Draft 2008 California 303(d)/305(b) Integrated Report

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name:	Chorro Creek
Water Body ID:	CAR3102201219980825120817
Water Body Type:	River & Stream

DECISION ID	4592
Pollutant:	Oxygen, Dissolved
Final Listing Decision:	Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2006)
Revision Status	Revised
Reason for Delisting:	State determines water quality standard is being met
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for removal from the section 303(d) list under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. The TMDL for Chorro Creek Nutrients and Dissolved Oxygen was approved by U.S. EPA on July 19, 2007. Twenty-three lines of evidence are available in the administrative record to assess this pollutant. LOE #1903 was the basis of the original listing, with 5 of 10 samples exceeding the Cold Freshwater Habitat water quality Objective. In this assessment multiple data sets are combined. Twelve of the 361 samples exceed the dissolved oxygen water quality objective for Cold Freshwater Habitat and none of 351 samples exceed the objective for Warm Freshwater Habitat (the original 10 samples were not included in the 2008 listing and thus were not evaluated for Warm Freshwater Habitat). In addition, 50 of 348 samples exceed the general water quality objective for oxygen saturation (applied as a single sample maximum). However, the Basin Plan objective states that the median oxygen saturation value shall not fall below 85% and the median value did not exceed this criterion. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Twelve of the 361 samples exceed the dissolved oxygen water quality objective for Cold Freshwater Habitat and none of 351 samples exceed the objective for Warm Freshwater Habitat (the original 10 samples were not included in the 2008 listing and thus were not evaluated for Warm Freshwater Habitat). Neither of these exceed the allowable frequency listed in Table 4.2 of the Listing Policy. In addition, the median value did not exceed the General Objective. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be removed from the section 303(d) list because applicable water quality standards for the pollutant are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 4592

LOE ID:	12602
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	15
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Oxygen, Dissolved.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	12603
Pollutant:	Dissolved oxygen saturation
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	15
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Oxygen, Saturation.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	12604
Pollutant:	Dissolved oxygen saturation
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	15
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Oxygen, Saturation.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	12595
Pollutant:	Dissolved oxygen saturation
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	13
Number of Exceedances:	10
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 10 of 13 samples exceed the criterion for Oxygen, Saturation.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 2 monitoring sites [ 310CAN-Chorro Creek at Canet Road, 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	12596
Pollutant:	Dissolved oxygen saturation
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	13
Number of Exceedances:	10
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 10 of 13 samples exceed the criterion for Oxygen, Saturation.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 2 monitoring sites [ 310CAN-Chorro Creek at Canet Road, 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	12601
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	15
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Oxygen, Dissolved.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, Cold Water Habitat Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	13453
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	58
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 58 samples exceed the criterion for Oxygen, Dissolved.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, Cold Water Habitat Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	13454
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	58
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 58 samples exceed the criterion for Oxygen, Dissolved.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	13455
Pollutant:	Dissolved oxygen saturation
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	58
Number of Exceedances:	9
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 9 of 58 samples exceed the criterion for Oxygen, Saturation.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	13456
Pollutant:	Dissolved oxygen saturation
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	58
Number of Exceedances:	9
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 9 of 58 samples exceed the criterion for Oxygen, Saturation.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14559
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Oxygen, Dissolved.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, Cold Water Habitat Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14560
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Oxygen, Dissolved.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14561
Pollutant:	Dissolved oxygen saturation
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 12 samples exceed the criterion for Oxygen, Saturation.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14562
Pollutant:	Dissolved oxygen saturation
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 12 samples exceed the criterion for Oxygen, Saturation.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	18192
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Oxygen, Dissolved.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, Cold Water Habitat Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/17/2003-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	18193
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Oxygen, Dissolved.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/17/2003-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	1903
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Adverse Biological Responses
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	10
Number of Exceedances:	5
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Regional Board staff is proposing that Chorro Creek (downstream of Chorro Creek Road) be listed as impaired for dissolved oxygen. The impairment is evidenced by depressed levels of dissolved oxygen measured during pre-dawn and 24-hour sampling periods. Continuous depressed levels of dissolved oxygen (< 7.0 mg/l) were found in Chorro Creek at TWB (approximately between 12a.m-8a.m.) during three 24-hour hourly sampling periods in July, August and September 2003. Continuous depressed levels of oxygen were also found between 5 p.m. and 7 a.m. at site added in September 2003 upstream of TWB (usTWB) (CCRWQCB, 2004o). Dissolved oxygen levels were within the COLD water quality objective at CAN during three 24-hour hourly sampling periods in July, August and September 2003 (CCAMP, 2004). Dissolved oxygen levels just under the COLD water quality objective (6.81-6.99 mg/l) were found during one of three sampling periods at an upstream site (CHO) in August 2003. Regional Board staff does not consider the segment upstream of CAN (and CHO) as impaired. Regional Board staff considers the segment between usTWB and TWB (downstream of Chorro Creek Road) as impaired for dissolved oxygen. The level of impairment between CAN and usTWB is unknown. Five out of 10 samples exceeded the COLD dissolved oxygen water quality objective.
Data Reference:	Placeholder reference 2006 303(d)
Water Quality Objective/Criterion:	COLD dissolved oxygen water quality objective of 7.0 mg/l.
Objective/Criterion Reference:	Placeholder reference 2006 303(d)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Chorro Creek (Calwater watershed no. 31022012) downstream of Chorro Creek Road. Measurements were taken in Chorro Creek at four locations (CHO, CAN, usTWB, and TWB).
Temporal Representation:	Hourly measurements were taken in three 24-hour hourly sampling periods in July, August, and September 2003.
Environmental Conditions:	Hourly dissolved oxygen measurements were taken using a recording dissolved oxygen meter.
QAPP Information:	Dissolved oxygen measurements in Chorro Creek were taken according to CCAMP 24-hour hourly recording meter sampling protocols. Morro Bay Volunteer Monitoring Program.
QAPP Information Reference(s):
LOE ID:	12639
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	13
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 13 samples exceed the criterion for Oxygen, Dissolved.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 2 monitoring sites [ 310CAN-Chorro Creek at Canet Road, 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	26476
Pollutant:	Dissolved oxygen saturation
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Fish Migration | Fish Spawning | Preservation of Rare & Endangered Species | Warm Freshwater Habitat | Wildlife Habitat
Number of Samples:	250
Number of Exceedances:	30
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Morro Bay Volunteer Monitoring Program data for Chorro Creek to determine beneficial use support and results are as follows: 30 of 250 samples exceed the criterion for Oxygen, Saturation.
Data Reference:	MBVMP Dissolved Oxygen, pH and Temperature data for Chorro Creek.
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 3 monitoring sites [ 310TWB-Chorro Creek at South Bay Blvd., 310CHO - Chorro Creek at the Highway 1 Bridge and 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period June 2002-December 2006. Chorro Creek monitoring sites are monitored monthly by Morro Bay Volunteer Monitoring Program volunteers. This monitoring is ongoing.
Environmental Conditions:
QAPP Information:	USEPA approved QAPP (Morro Bay National Estuary Program's Volunteer Monitoring Program Quality Assurance Program Plan, version 4.3. October 2008. The author is the Morro Bay National Estuary Program).
QAPP Information Reference(s):
LOE ID:	12638
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	13
Number of Exceedances:	3
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 3 of 13 samples exceed the criterion for Oxygen, Dissolved.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, Cold Water Habitat Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 2 monitoring sites [ 310CAN-Chorro Creek at Canet Road, 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	26479
Pollutant:	Dissolved oxygen saturation
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat | Fish Migration | Fish Spawning | Preservation of Rare & Endangered Species | Wildlife Habitat
Number of Samples:	250
Number of Exceedances:	30
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Morro Bay Volunteer Monitoring Program data for Chorro Creek to determine beneficial use support and results are as follows: 30 of 250 samples exceed the criterion for Oxygen, Saturation.
Data Reference:	MBVMP Dissolved Oxygen, pH and Temperature data for Chorro Creek.
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 3 monitoring sites [ 310TWB-Chorro Creek at South Bay Blvd., 310CHO - Chorro Creek at the Highway 1 Bridge and 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period June 2002-December 2006. Chorro Creek monitoring sites are monitored monthly by Morro Bay Volunteer Monitoring Program volunteers. This monitoring is ongoing.
Environmental Conditions:
QAPP Information:	USEPA approved QAPP (Morro Bay National Estuary Program's Volunteer Monitoring Program Quality Assurance Program Plan, version 4.3. October 2008. The author is the Morro Bay National Estuary Program).
QAPP Information Reference(s):
LOE ID:	26478
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat | Fish Migration | Fish Spawning | Preservation of Rare & Endangered Species | Wildlife Habitat
Number of Samples:	250
Number of Exceedances:	0
Data and Information Type:	Not Specified
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Morro Bay Volunteer Monitoring Program data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 250 samples exceed the criterion for Dissolved Oxygen.
Data Reference:	MBVMP Dissolved Oxygen, pH and Temperature data for Chorro Creek.
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, Cold Water Habitat Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 3 monitoring sites [ 310TWB-Chorro Creek at South Bay Blvd., 310CHO - Chorro Creek at the Highway 1 Bridge and 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period June 2002-December 2006. Chorro Creek monitoring sites are monitored monthly by Morro Bay Volunteer Monitoring Program volunteers. This monitoring is ongoing.
Environmental Conditions:
QAPP Information:	USEPA approved QAPP (Morro Bay National Estuary Program's Volunteer Monitoring Program Quality Assurance Program Plan, version 4.3. October 2008. The author is the Morro Bay National Estuary Program).
QAPP Information Reference(s):
LOE ID:	26477
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Fish Migration | Fish Spawning | Preservation of Rare & Endangered Species | Warm Freshwater Habitat | Wildlife Habitat
Number of Samples:	250
Number of Exceedances:	3
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Morro Bay Volunteer Monitoring Program data for Chorro Creek to determine beneficial use support and results are as follows: 3 of 250 samples exceed the criterion for Dissolved Oxygen.
Data Reference:	MBVMP Dissolved Oxygen, pH and Temperature data for Chorro Creek.
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, Cold Water Habitat Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 3 monitoring sites [ 310TWB-Chorro Creek at South Bay Blvd., 310CHO - Chorro Creek at the Highway 1 Bridge and 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period June 2002-December 2006. Chorro Creek monitoring sites are monitored monthly by Morro Bay Volunteer Monitoring Program volunteers. This monitoring is ongoing.
Environmental Conditions:
QAPP Information:	USEPA approved QAPP (Morro Bay National Estuary Program's Volunteer Monitoring Program Quality Assurance Program Plan, version 4.3. October 2008. The author is the Morro Bay National Estuary Program).
QAPP Information Reference(s):

DECISION ID	4241
Pollutant:	Fecal Coliform
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2006)
Revision Status	Revised
Sources:	Source Unknown
TMDL Name:	Morro Bay Pathogens
TMDL Project Code:	22
Date TMDL Approved by USEPA:	01/20/2004
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	The Morro Bay Pathogens TMDL (including Chorro Creek) was approved by RWQCB on May 16, 2003 and subsequently approved by USEPA on January 20, 2004. This pollutant is being considered for delisting under sections 4.2 of the Listing Policy. Under section 4.2 a single line of evidence is necessary to assess listing status. According to the binomial distribution, waters shall be placed on the section 303(d) list if the number of measured exceedances supports rejection of the null hypothesis as presented in Table 3.2. Eight lines of evidence are available in the administrative record to assess this pollutant. Two hundred and four of 941 samples exceed the water quality objectives for Water Contact Recreation, and this supports rejection of the null hypothesis. Eight hundred sixty nine of these 941 samples originated with a previous listing cycle and were only evaluated for Water Contact Recreation. The remaining 72 samples (new for this listing cycle) were evaluated for Non-Contact Recreation as well. Two of these 72 samples exceed the water quality objective for Non-Contact Recreation; therefore, this beneficial use is fully supported. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two hundred-and-four of 941 samples exceed the water quality objectives for Water Contact Recreation, and these exceed the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
SWRCB Board Decision / Staff Recommendation:	After review of the available data and information for this recommendation, SWRCB staff conclude that the water body should be placed in the Water Quality Limited Segments Being Addressed category of the section 303(d) list because a TMDL has been approved by USEPA and an implementation plan has been approved.
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 4241

LOE ID:	17563
Pollutant:	Fecal Coliform
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Non-Contact Recreation
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Coliform, Fecal.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected on a single day 5/17/2003. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	17562
Pollutant:	Fecal Coliform
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Water Contact Recreation
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Coliform, Fecal.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 200 MPN/100 ml, nor shall more than ten percent of total samples during any 30-day period exceed 400 MPN/100 ml.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected on a single day 5/17/2003. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	11614
Pollutant:	Fecal Coliform
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Non-Contact Recreation
Number of Samples:	57
Number of Exceedances:	1
Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 57 samples exceed the criterion for Coliform, Fecal.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-11/15/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11613
Pollutant:	Fecal Coliform
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Water Contact Recreation
Number of Samples:	57
Number of Exceedances:	7
Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 7 of 57 samples exceed the criterion for Coliform, Fecal.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 200 MPN/100 ml, nor shall more than ten percent of total samples during any 30-day period exceed 400 MPN/100 ml.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-11/15/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	10824
Pollutant:	Fecal Coliform
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Non-Contact Recreation
Number of Samples:	14
Number of Exceedances:	1
Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 14 samples exceed the criterion for Coliform, Fecal.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	10808
Pollutant:	Fecal Coliform
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Water Contact Recreation
Number of Samples:	14
Number of Exceedances:	4
Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 4 of 14 samples exceed the criterion for Coliform, Fecal.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 200 MPN/100 ml, nor shall more than ten percent of total samples during any 30-day period exceed 400 MPN/100 ml.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	1902
Pollutant:	Fecal Coliform
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Water Contact Recreation
Number of Samples:	869
Number of Exceedances:	193
Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	One hundred ninety-three of 869 samples exceed the water quality objectives.
Data Reference:	Placeholder reference 2006 303(d)
Water Quality Objective/Criterion:	Basin Plan: Fecal coliform concentration, based on minimum of not less than five samples or any 30-day period, shall not exceed a log mean of 200/100 ml, nor shall more than ten percent of the total samples during any 30-day period exceed 400/100 ml.
Objective/Criterion Reference:	Placeholder reference 2006 303(d)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Six stations were sampled.
Temporal Representation:	There were weekly or bi-weekly sampling events from 6/93 to 5/99.
Environmental Conditions:
QAPP Information:	Morro Bay National Monitoring Program (MBNMP) QA/QC.
QAPP Information Reference(s):
LOE ID:	1901
Pollutant:	Fecal Coliform
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded
Beneficial Use:	Water Contact Recreation
Number of Samples:	0
Number of Exceedances:	0
Data and Information Type:	Not Specified
Data Used to Assess Water Quality:	Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference:	Placeholder reference 2006 303(d)
Water Quality Objective/Criterion:
Objective/Criterion Reference:
Evaluation Guideline:
Guideline Reference:
Spatial Representation:
Temporal Representation:
Environmental Conditions:
QAPP Information:	QA Info Missing
QAPP Information Reference(s):

DECISION ID	12212
Pollutant:	Ammonia (Unionized)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. None of the 83 samples exceed the water quality objectives for Cold or Warm Freshwater Habitat. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 83 samples exceed the water quality objectives for Cold or Warm Freshwater Habitat and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12212

LOE ID:	9934
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	15
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin General Objective, Chapter III, Section II.A.2 (General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries) states that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	9933
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	15
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin General Objective, Chapter III, Section II.A.2 (General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries) states that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	9590
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	56
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 56 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin General Objective, Chapter III, Section II.A.2 (General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries) states that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	9591
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	56
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 56 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin General Objective, Chapter III, Section II.A.2 (General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries) states that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14542
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin General Objective, Chapter III, Section II.A.2 (General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries) states that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14541
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin General Objective, Chapter III, Section II.A.2 (General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries) states that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15959
Pollutant:	Anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with toxicity to result in adding that pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15959

LOE ID:	15830
Pollutant:	Anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Anthracene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for anthracene is 845 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	15831
Pollutant:	Anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Anthracene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for anthracene is 845 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12216
Pollutant:	Arsenic
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 and 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status. Under section 3.6 pollutant specific sediment data showing exceedances of the sediment guideline can only result in a listing for that pollutant if there is also sediment toxicity. Two lines of evidence are available in the administrative record to assess Arsenic concentrations. Neither of the two samples exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Neither of the two samples exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses, and did not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12216

LOE ID:	15642
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Arsenic.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for arsenic is 33 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	15655
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Arsenic.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for arsenic is 33 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15960
Pollutant:	Benzo(a)pyrene (3,4-Benzopyrene -7-d)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with toxicity to result in adding that pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15960

LOE ID:	15591
Pollutant:	Benzo(a)pyrene (3,4-Benzopyrene -7-d)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Benzo(a)pyrene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for Benzo(a)Pyrene is 1450 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	15578
Pollutant:	Benzo(a)pyrene (3,4-Benzopyrene -7-d)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Benzo(a)pyrene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for Benzo(a)Pyrene is 1450 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15961
Pollutant:	Benzo[a]anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with toxicity to result in adding that pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Use this to the RB recommendation. After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15961

LOE ID:	14834
Pollutant:	Benzo[a]anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Benzo(a)anthracene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for Benzo(a)anthracene is 1050 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14818
Pollutant:	Benzo[a]anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Benzo(a)anthracene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for Benzo(a)anthracene is 1050 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12218
Pollutant:	Boron
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the 60 samples exceed the water quality objective for Agricultural Supply. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 60 samples exceed the water quality objective for Agricultural Supply and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12218

LOE ID:	9991
Pollutant:	Boron
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Agricultural Supply
Number of Samples:	52
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 52 samples exceed the criterion for Boron, dissolved.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in Table 3.4 (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). Table 3-4 (page III-9) lists the maximum concentration for boron for irrigation supply is 0.75 mg/L.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	9935
Pollutant:	Boron
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Agricultural Supply
Number of Samples:	8
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 8 samples exceed the criterion for Boron, dissolved.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. In addition, waters used for irrigation and livestock watering shall not exceed concentrations for those chemicals listed in Table 3.4 (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). Table 3-4 (page III-9) lists the maximum concentration for boron for irrigation supply is 0.75 mg/L.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-8/5/2002. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12220
Pollutant:	Cadmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 and 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status. Under section 3.6 pollutant specific sediment data showing exceedances of the sediment guideline can only result in a listing for that pollutant if there is also sediment toxicity. Two lines of evidence are available in the administrative record to assess Cadmium concentrations. Neither of the two samples exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Neither of the two samples exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses, and did not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12220

LOE ID:	15440
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Cadmium.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for cadmium is 4.98 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	15439
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Cadmium.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for cadmium is 4.98 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12223
Pollutant:	Chlorophyll-a
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Eight lines of evidence are available in the administrative record to assess this pollutant. None of the 84 samples exceed the Evaluation Guideline (Sigler et al., 1984) applied to protect for aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 84 samples exceed the Evaluation Guideline (Sigler et al., 1984) applied to protect for aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12223

LOE ID:	10007
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	56
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 56 samples exceed the criterion for Chlorophyll a.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	Water quality standards table
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	12600
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	15
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Chlorophyll a.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	Water quality standards table
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	12585
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	15
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Chlorophyll a.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	Water quality standards table
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14543
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Chlorophyll a.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	Water quality standards table
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14544
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Chlorophyll a.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	Water quality standards table
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	13490
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chlorophyll a.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	Water quality standards table
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 7/3/2001. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	13491
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chlorophyll a.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	Water quality standards table
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 7/3/2001. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	10006
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	56
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 56 samples exceed the criterion for Chlorophyll a.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	Water quality standards table
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15970
Pollutant:	Chlorpyrifos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. One of the 2 samples exceed the water Evaluation Guideline (Sipmann and Finlayson, 2000) applied to protect for aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of the 2 samples exceed the water Evaluation Guideline (Sipmann and Finlayson, 2000) applied to protect for aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15970

LOE ID:	16262
Pollutant:	Chlorpyrifos
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (00SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chlorpyrifos.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	One hour average maximum concentration 0.025 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 3/27/2002. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	16263
Pollutant:	Chlorpyrifos
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (00SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chlorpyrifos.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	One hour average maximum concentration 0.025 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 3/27/2002. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	16234
Pollutant:	Chlorpyrifos
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Chlorpyrifos.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	One hour average maximum concentration 0.025 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	16235
Pollutant:	Chlorpyrifos
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Chlorpyrifos.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	One hour average maximum concentration 0.025 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12226
Pollutant:	Chromium (total)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 and 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status. Under section 3.6 pollutant specific sediment data showing exceedances of the sediment guideline can only result in a listing for that pollutant if there is also sediment toxicity. Two lines of evidence are available in the administrative record to assess Chromium concentrations and four lines of evidence are available in the administrative record to assess sediment toxicity. None of the samples were toxic to test organisms. Therefore, Chromium cannot be associated with toxic effects in this waterbody. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples were toxic to test organisms. Therefore, Chromium cannot be associated with toxic effects in this waterbody. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded. RWQCB staff have investigated metal concentrations in this watershed and others in the vicinity and have noted that the ambient concentrations are relatively high, presumeably from the serpentine geology of the area.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12226

LOE ID:	16085
Pollutant:	Chromium (total)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	2
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 2 of 2 samples exceed the criterion for Chromium.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for chromium is 111 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	16086
Pollutant:	Chromium (total)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	2
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 2 of 2 samples exceed the criterion for Chromium.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for chromium is 111 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15962
Pollutant:	Chrysene (C1-C4)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with toxicity to result in adding that pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15962

LOE ID:	15967
Pollutant:	Chrysene (C1-C4)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chrysene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for Chrysene is 1290 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	15966
Pollutant:	Chrysene (C1-C4)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chrysene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for Chrysene is 1290 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12230
Pollutant:	Copper
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 and 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status. Under section 3.6 pollutant specific sediment data showing exceedances of the sediment guideline can only result in a listing for that pollutant if there is also sediment toxicity. Two lines of evidence are available in the administrative record to assess Arsenic concentrations. Neither of the two samples exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Neither of the two samples exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses, and did not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12230

LOE ID:	16049
Pollutant:	Copper
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Copper.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for cooper is 149 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	16050
Pollutant:	Copper
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Copper.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for cooper is 149 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15971
Pollutant:	Diazinon
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. Neither of the 2 samples exceed the water Evaluation Guideline (Sipmann and Finlayson, 2000) applied to protect for aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Neither of the 2 samples exceed the water Evaluation Guideline (Sipmann and Finlayson, 2000) applied to protect for aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15971

LOE ID:	16637
Pollutant:	Diazinon
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (00SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Diazinon.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	One hour average maximum concentration 0.16 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 3/27/2002. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	16655
Pollutant:	Diazinon
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Diazinon.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	One hour average maximum concentration 0.16 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	16656
Pollutant:	Diazinon
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Diazinon.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	One hour average maximum concentration 0.16 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	16636
Pollutant:	Diazinon
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (00SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Diazinon.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	One hour average maximum concentration 0.16 ug/L as stated in Sipmann and Finlayson (2000).
Guideline Reference:	Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 3/27/2002. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15963
Pollutant:	Dieldrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with toxicity to result in adding that pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15963

LOE ID:	16725
Pollutant:	Dieldrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Dieldrin.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for dieldrin is 61.8 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	16724
Pollutant:	Dieldrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Dieldrin.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for dieldrin is 61.8 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12231
Pollutant:	Electrical Conductivity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. None of the 83 samples exceed the water quality objective for Agricultural Supply. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 83 samples exceed the water quality objective for Agricultural Supply and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12231

LOE ID:	10825
Pollutant:	Electrical Conductivity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	15
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Conductivity(Us).
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when conductivity exceeds 3.0 mS/cm in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	17590
Pollutant:	Electrical Conductivity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Conductivity(Us).
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when conductivity exceeds 3.0 mS/cm in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/17/2003-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	11615
Pollutant:	Electrical Conductivity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	58
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 58 samples exceed the criterion for Conductivity(Us).
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when conductivity exceeds 3.0 mS/cm in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11651
Pollutant:	Electrical Conductivity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Conductivity(Us).
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when conductivity exceeds 3.0 mS/cm in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15964
Pollutant:	Endrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with toxicity to result in adding that pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15964

LOE ID:	16575
Pollutant:	Endrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Endrin.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for endrin is 207 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	16576
Pollutant:	Endrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Endrin.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for endrin is 207 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15965
Pollutant:	Fluoranthene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with toxicity to result in adding that pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15965

LOE ID:	16423
Pollutant:	Fluoranthene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Fluoranthene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for Fluoranthene is 2,230 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	16422
Pollutant:	Fluoranthene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Fluoranthene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for Fluoranthene is 2,230 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15966
Pollutant:	Fluorene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with toxicity to result in adding that pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15966

LOE ID:	16491
Pollutant:	Fluorene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Fluorene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for fluorene is 536 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	16492
Pollutant:	Fluorene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Fluorene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for fluorene is 536 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12239
Pollutant:	Lead
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 and 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status. Under section 3.6 pollutant specific sediment data showing exceedances of the sediment guideline can only result in a listing for that pollutant if there is also sediment toxicity. Two lines of evidence are available in the administrative record to assess Lead concentrations. Neither of the two samples exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Neither of the two samples exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses, and did not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12239

LOE ID:	17373
Pollutant:	Lead
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Lead.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for lead is 128 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	17372
Pollutant:	Lead
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Lead.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for lead is 128 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12240
Pollutant:	Mercury
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 and 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status. Under section 3.6 pollutant specific sediment data showing exceedances of the sediment guideline can only result in a listing for that pollutant if there is also sediment toxicity. Two lines of evidence are available in the administrative record to assess Mercury concentrations. Neither of the two samples exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Neither of the two samples exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses, and did not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12240

LOE ID:	17205
Pollutant:	Mercury
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Mercury.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for mercury is 1.06 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	17218
Pollutant:	Mercury
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Mercury.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for mercury is 1.06 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15967
Pollutant:	Naphthalene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with toxicity to result in adding that pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15967

LOE ID:	17272
Pollutant:	Naphthalene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Naphthalene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for naphthalene is 561 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	17271
Pollutant:	Naphthalene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Naphthalene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for naphthalene is 561 ug/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12242
Pollutant:	Nickel
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 and 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status. Under section 3.6 pollutant specific sediment data showing exceedances of the sediment guideline can only result in a listing for that pollutant if there is also sediment toxicity. Two lines of evidence are available in the administrative record to assess Nickel concentrations and four lines of evidence are available in the administrative record to assess sediment toxicity. None of the samples were toxic to test organisms. Therefore, Nickel cannot be associated with toxic effects in this waterbody. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples were toxic to test organisms. Therefore, Nickel cannot be associated with toxic effects in this waterbody. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded. RWQCB staff have investigated metal concentrations in this watershed and others in the vicinity and have noted that the ambient concentrations are relatively high, presumeably from the serpentine geology of the area.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12242

LOE ID:	17107
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	2
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 2 of 2 samples exceed the criterion for Nickel.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for nickel is 48.6 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	17106
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	2
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 2 of 2 samples exceed the criterion for Nickel.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for nickel is 48.6 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12214
Pollutant:	Nitrogen, ammonia (Total Ammonia)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three line of evidence is available in the administrative record to assess this pollutant. None of the 87 samples exceed the Evaluation Guideline (EPA's Lifetime Health advisory level, 2006) applied to protect the Municipal & Domestic Supply beneficial use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 87 samples exceed the Evaluation Guideline (EPA's Lifetime Health advisory level, 2006) applied to protect the Municipal & Domestic Supply beneficial use and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12214

LOE ID:	15247
Pollutant:	Ammonia as Nitrogen
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	12
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Ammonia As N, Total.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	USEPA Health Advisory 2006 Edition of the Drinking Water Standards and Health Advisories (EPA 822-R-06-013, 2006).
Objective/Criterion Reference:	2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
Evaluation Guideline:	EPA's Lifetime Health advisory level for total ammonia is 30.0 mg/L as stated on page 8 of the 2006 edition of the drinking water standards and health advisories. This Advisory Level is defined as "the concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects for up to ten days of exposure."
Guideline Reference:	2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	9990
Pollutant:	Ammonia as Nitrogen
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	59
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 59 samples exceed the criterion for Ammonia as N, Total.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	USEPA Health Advisory 2006 Edition of the Drinking Water Standards and Health Advisories (EPA 822-R-06-013, 2006).
Objective/Criterion Reference:	2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
Evaluation Guideline:	EPA's Lifetime Health advisory level for total ammonia is 30.0 mg/L as stated on page 8 of the 2006 edition of the drinking water standards and health advisories. This Advisory Level is defined as "the concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects for up to ten days of exposure."
Guideline Reference:	2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	9932
Pollutant:	Ammonia as Nitrogen
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	16
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 16 samples exceed the criterion for Ammonia as N, Total.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	USEPA Health Advisory 2006 Edition of the Drinking Water Standards and Health Advisories (EPA 822-R-06-013, 2006).
Objective/Criterion Reference:	2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
Evaluation Guideline:	EPA's Lifetime Health advisory level for total ammonia is 30.0 mg/L as stated on page 8 of the 2006 edition of the drinking water standards and health advisories. This Advisory Level is defined as "the concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects for up to ten days of exposure."
Guideline Reference:	2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15968
Pollutant:	Phenanthrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with toxicity to result in adding that pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15968

LOE ID:	16940
Pollutant:	Phenanthrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Phenanthrene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for Phenanthrene is 1170 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	16939
Pollutant:	Phenanthrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Phenanthrene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for Phenanthrene is 1170 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15969
Pollutant:	Pyrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with toxicity to result in adding that pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. The sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15969

LOE ID:	17057
Pollutant:	Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Pyrene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for Pyrene is 1520 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	17070
Pollutant:	Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Pyrene.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for Pyrene is 1520 ug/Kg dry weight (Macdonald et al. 2000)
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12250
Pollutant:	Salinity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. None of the 88 samples exceed the water quality objective for Agricultural Supply. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 88 samples exceed the water quality objective for Agricultural Supply and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12250

LOE ID:	13492
Pollutant:	Salinity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Salinity.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when salinity exceeds 3.0 ppt in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/30/2001. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	12620
Pollutant:	Salinity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	15
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Salinity.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when salinity exceeds 3.0 ppt in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14596
Pollutant:	Salinity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	12
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Salinity.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when salinity exceeds 3.0 ppt in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	13472
Pollutant:	Salinity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	58
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 58 samples exceed the criterion for Salinity.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when salinity exceeds 3.0 ppt in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15972
Pollutant:	Sediment Toxicity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under section 3.6 a single line of evidence is necessary to assess listing status for toxicity. Four lines of evidence are available in the administrative record to assess this pollutant in sediment samples. Neither of the samples were toxic to invertebrate test organisms (exhibit a significant increase in mortality compared to the laboratory control) and therefore do not exceed the narrative General Objective for toxicity, set to protect for aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. of the samples were toxic to invertebrate test organisms. Therefore, this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15972

LOE ID:	23827
Pollutant:	Invertebrate Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Hyalella azteca Survival (%) 10 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected on a single day 5/17/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	23826
Pollutant:	Invertebrate Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Hyalella azteca Survival (%) 10 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected on a single day 5/17/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	23805
Pollutant:	Invertebrate Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Hyalella azteca Survival (%) 10 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	23804
Pollutant:	Invertebrate Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Hyalella azteca Survival (%) 10 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12252
Pollutant:	Temperature, water
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. One of the 101 samples exceed the Evaluation Guideline (Moyle 1976) applied to protect the Cold Freshwater Habitat beneficial use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of the 101 samples exceed the Evaluation Guideline (Moyle 1976) applied to protect the Cold Freshwater Habitat beneficial use and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12252

LOE ID:	12597
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	13
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 13 samples exceed the criterion for Water Temperature.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (General Objective in Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference:	Inland Fishes of California
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 2 monitoring sites [ 310CAN-Chorro Creek at Canet Road, 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	13475
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	58
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 58 samples exceed the criterion for Water Temperature.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (General Objective in Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference:	Inland Fishes of California
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14611
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 12 samples exceed the criterion for Water Temperature.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (General Objective in Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference:	Inland Fishes of California
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	12623
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	15
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Water Temperature.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (General Objective in Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference:	Inland Fishes of California
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	18594
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Water Temperature.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (General Objective in Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference:	Inland Fishes of California
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/17/2003-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):

DECISION ID	12253
Pollutant:	Turbidity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Ten lines of evidence are available in the administrative record to assess this pollutant. Two of the 82 samples exceed the Evaluation Guideline (Sigler et al., 1984) applied to protect for aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two of the 82 samples exceed the Evaluation Guideline (Sigler et al., 1984) applied to protect for aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12253

LOE ID:	14597
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	10
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 10 samples exceed the criterion for Turbidity(NTU).
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	18703
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Turbidity(NTU).
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/17/2003-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	14598
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	10
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 10 samples exceed the criterion for Turbidity(NTU).
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	13474
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	51
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 51 samples exceed the criterion for Turbidity(NTU).
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	13493
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Turbidity(NTU).
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/30/2001. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	12622
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	15
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 15 samples exceed the criterion for Turbidity(NTU).
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	13509
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Turbidity(NTU).
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/30/2001. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	12621
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	15
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 15 samples exceed the criterion for Turbidity(NTU).
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	18704
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Turbidity(NTU).
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/17/2003-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	13473
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	51
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 51 samples exceed the criterion for Turbidity(NTU).
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	15973
Pollutant:	Unknown Toxicity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 and section 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Ten lines of evidence are available in the administrative record to assess this pollutant in water samples. None of the samples were toxic to test organisms (exhibited a significant increase in mortality or decrease in cell density compared to the laboratory control) and therefore do not exceed the narrative General Objective for toxicity, set to protect for aquatic life beneficial uses. The following is a summary of the results from individual toxicity tests. None of the 4 samples (tested for toxicity to plants) exhibited significant reduction in cell density relative to the control. In addition, none of the 4 samples (tested for toxicity to vertebrate test organisms) exhibited a significant increase in mortality compared to the laboratory control. Lastly, none of the 4 samples, tested for toxicity to invertebrate test organisms exhibited a significant increase in mortality compared to the laboratory control. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples were toxic to test organisms. Therefore, this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 15973

LOE ID:	23808
Pollutant:	Vertebrate Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Toxicity, Pimephales promelas Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 2/24/2006-9/27/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	23833
Pollutant:	Plant Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Toxicity, Selenastrum capricornutum Growth (Cell Density) 4 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Significant reduction in cell count of test organism relative to the control (alpha < 0.05) and cell count <80% of control.
Guideline Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 2/24/2006-9/27/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	23831
Pollutant:	Vertebrate Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (00SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Pimephales promelas Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 3/27/2002. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	23691
Pollutant:	Invertebrate Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (00SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Ceriodaphnia dubia Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 3/27/2002. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	23832
Pollutant:	Plant Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Toxicity, Selenastrum capricornutum Growth (Cell Density) 4 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Significant reduction in cell count of test organism relative to the control (alpha < 0.05) and cell count <80% of control.
Guideline Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 2/24/2006-9/27/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	23690
Pollutant:	Invertebrate Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (00SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Ceriodaphnia dubia Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 3/27/2002. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	23809
Pollutant:	Vertebrate Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (00SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Pimephales promelas Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 3/27/2002. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	23821
Pollutant:	Invertebrate Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Toxicity, Ceriodaphnia dubia Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 2/24/2006-9/27/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	23822
Pollutant:	Invertebrate Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Toxicity, Ceriodaphnia dubia Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 2/24/2006-9/27/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	23807
Pollutant:	Vertebrate Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPsouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Toxicity, Pimephales promelas Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.
Guideline Reference:	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 2/24/2006-9/27/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12260
Pollutant:	Zinc
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 and 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status. Under section 3.6 pollutant specific sediment data showing exceedances of the sediment guideline can only result in a listing for that pollutant if there is also sediment toxicity. Two lines of evidence are available in the administrative record to assess Zinc concentrations. Neither of the two samples exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 16 samples to make a "use rating" decision of Fully Supporting. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Neither of the two samples exceed the Evaluation Guideline (MacDonald et al. 2000) as it applies to aquatic life beneficial uses, and did not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12260

LOE ID:	17685
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Zinc.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for zinc is 459 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	17699
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (03SW3001) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Zinc.
Data Reference:	Final Data File used for assessment: SWAMP Toxicity Data 2001-06
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	In fresh water sediments the probable effects level (predictive of sediment toxicity) for zinc is 459 mg/Kg dry weight (MacDonald et al. 2000).
Guideline Reference:	Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected on a single day 4/1/2004. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	12257
Pollutant:	pH
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under sections 2.1 and 3.2 of the Listing Policy. Thirty-six lines of evidence are available in the administrative record to assess this pollutant. Twelve of the 343 samples exceed the Agricultural Supply water quality objective, 3 of the 343 samples exceed the Cold and Warm Freshwater Habitat water quality objectives and 18 of the 343 samples exceed the numeric objectives for Municipal & Domestic Supply, Non-Contact Recreation and Water Contact Recreation. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Twelve of the 343 samples exceed the Agricultural Supply water quality objective, 3 of the 343 samples exceed the Cold and Warm Freshwater Habitat water quality objectives and 18 of the 343 samples exceed the numeric objectives for Municipal & Domestic Supply, Non-Contact Recreation and Water Contact Recreation. None of these exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12257

LOE ID:	18882
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/17/2003-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	18883
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Municipal and Domestic Supply Objectives, Section II.A.2.a states the following: The pH value shall neither be depressed below 6.5 or raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/17/2003-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	18884
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Water Contact Recreation
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/17/2003-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	18885
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Non-Contact Recreation
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/17/2003-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	18886
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/17/2003-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	18866
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/17/2003-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	14579
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Non-Contact Recreation
Number of Samples:	12
Number of Exceedances:	4
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 4 of 12 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	10826
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	15
Number of Exceedances:	2
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 2 of 15 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	10827
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	15
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	10828
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	15
Number of Exceedances:	3
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 3 of 15 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Municipal and Domestic Supply Objectives, Section II.A.2.a states the following: The pH value shall neither be depressed below 6.5 or raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	10844
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Water Contact Recreation
Number of Samples:	15
Number of Exceedances:	3
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 3 of 15 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	10845
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Non-Contact Recreation
Number of Samples:	15
Number of Exceedances:	3
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 3 of 15 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	10846
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	15
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11654
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	7
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 7 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Municipal and Domestic Supply Objectives, Section II.A.2.a states the following: The pH value shall neither be depressed below 6.5 or raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11634
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Water Contact Recreation
Number of Samples:	58
Number of Exceedances:	8
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 8 of 58 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11635
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Non-Contact Recreation
Number of Samples:	58
Number of Exceedances:	8
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 8 of 58 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11668
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Water Contact Recreation
Number of Samples:	7
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 7 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11669
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Non-Contact Recreation
Number of Samples:	7
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 7 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11670
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11631
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	58
Number of Exceedances:	5
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 5 of 58 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11632
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	58
Number of Exceedances:	3
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 3 of 58 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11633
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	58
Number of Exceedances:	8
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 8 of 58 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Municipal and Domestic Supply Objectives, Section II.A.2.a states the following: The pH value shall neither be depressed below 6.5 or raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11650
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	58
Number of Exceedances:	3
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 3 of 58 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11652
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11653
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 7/3/2001-8/5/2006. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14575
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	12
Number of Exceedances:	3
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 3 of 12 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14576
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Cold Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14577
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	12
Number of Exceedances:	4
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 4 of 12 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Municipal and Domestic Supply Objectives, Section II.A.2.a states the following: The pH value shall neither be depressed below 6.5 or raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14595
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Aquatic Life Use:	Warm Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	14578
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Water Contact Recreation
Number of Samples:	12
Number of Exceedances:	4
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 4 of 12 samples exceed the criterion for pH.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	26485
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Non-Contact Recreation
Number of Samples:	248
Number of Exceedances:	2
Data and Information Type:	Not Specified
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Morro Bay Volunteer Monitoring Program data for Chorro Creek to determine beneficial use support and results are as follows: 2 of 248 samples exceed the criterion for pH.
Data Reference:	MBVMP Dissolved Oxygen, pH and Temperature data for Chorro Creek.
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 4 monitoring sites [ 310TWB-Chorro Creek at South Bay Blvd., 310CHO - Chorro Creek at the Highway 1 Bridge, 310CAN-Chorro Creek at Canet Road and 310CER - Chorro Creek at
Temporal Representation:	Data was collected over the time period June 2002-December 2006. Chorro Creek monitoring sites are monitored monthly by Morro Bay Volunteer Monitoring Program volunteers. This monitoring is ongoing.
Environmental Conditions:
QAPP Information:	USEPA approved QAPP (Morro Bay National Estuary Program's Volunteer Monitoring Program Quality Assurance Program Plan, version 4.3. October 2008. The author is the Morro Bay National Estuary Program).
QAPP Information Reference(s):
LOE ID:	26484
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	248
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Morro Bay Volunteer Monitoring Program data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 248 samples exceed the criterion for pH.
Data Reference:	MBVMP Dissolved Oxygen, pH and Temperature data for Chorro Creek.
Water Quality Objective/Criterion:	Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For Cold Freshwater Habitat the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 4 monitoring sites [ 310TWB-Chorro Creek at South Bay Blvd., 310CHO - Chorro Creek at the Highway 1 Bridge, 310CAN-Chorro Creek at Canet Road and 310CER - Chorro Creek at
Temporal Representation:	Data was collected over the time period June 2002-December 2006. Chorro Creek monitoring sites are monitored monthly by Morro Bay Volunteer Monitoring Program volunteers. This monitoring is ongoing.
Environmental Conditions:
QAPP Information:	USEPA approved QAPP (Morro Bay National Estuary Program's Volunteer Monitoring Program Quality Assurance Program Plan, version 4.3. October 2008. The author is the Morro Bay National Estuary Program).
QAPP Information Reference(s):
LOE ID:	26482
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	248
Number of Exceedances:	2
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Morro Bay Volunteer Monitoring Program data for Chorro Creek to determine beneficial use support and results are as follows: 2 of 248 samples exceed the criterion for pH.
Data Reference:	MBVMP Dissolved Oxygen, pH and Temperature data for Chorro Creek.
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 4 monitoring sites [ 310TWB-Chorro Creek at South Bay Blvd., 310CHO - Chorro Creek at the Highway 1 Bridge, 310CAN-Chorro Creek at Canet Road and 310CER - Chorro Creek at
Temporal Representation:	Data was collected over the time period June 2002-December 2006. Chorro Creek monitoring sites are monitored monthly by Morro Bay Volunteer Monitoring Program volunteers. This monitoring is ongoing.
Environmental Conditions:
QAPP Information:	USEPA approved QAPP (Morro Bay National Estuary Program's Volunteer Monitoring Program Quality Assurance Program Plan, version 4.3. October 2008. The author is the Morro Bay National Estuary Program).
QAPP Information Reference(s):
LOE ID:	26487
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	248
Number of Exceedances:	2
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Morro Bay Volunteer Monitoring Program data for Chorro Creek to determine beneficial use support and results are as follows: 2 of 248 samples exceed the criterion for pH.
Data Reference:	MBVMP Dissolved Oxygen, pH and Temperature data for Chorro Creek.
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 4 monitoring sites [ 310TWB-Chorro Creek at South Bay Blvd., 310CHO - Chorro Creek at the Highway 1 Bridge, 310CAN-Chorro Creek at Canet Road and 310CER - Chorro Creek at
Temporal Representation:	Data was collected over the time period June 2002-December 2006. Chorro Creek monitoring sites are monitored monthly by Morro Bay Volunteer Monitoring Program volunteers. This monitoring is ongoing.
Environmental Conditions:
QAPP Information:	USEPA approved QAPP (Morro Bay National Estuary Program's Volunteer Monitoring Program Quality Assurance Program Plan, version 4.3. October 2008. The author is the Morro Bay National Estuary Program).
QAPP Information Reference(s):
LOE ID:	26486
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Water Contact Recreation
Number of Samples:	248
Number of Exceedances:	2
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Morro Bay Volunteer Monitoring Program data for Chorro Creek to determine beneficial use support and results are as follows: 2 of 248 samples exceed the criterion for pH.
Data Reference:	MBVMP Dissolved Oxygen, pH and Temperature data for Chorro Creek.
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 4 monitoring sites [ 310TWB-Chorro Creek at South Bay Blvd., 310CHO - Chorro Creek at the Highway 1 Bridge, 310CAN-Chorro Creek at Canet Road and 310CER - Chorro Creek at
Temporal Representation:	Data was collected over the time period June 2002-December 2006. Chorro Creek monitoring sites are monitored monthly by Morro Bay Volunteer Monitoring Program volunteers. This monitoring is ongoing.
Environmental Conditions:
QAPP Information:	USEPA approved QAPP (Morro Bay National Estuary Program's Volunteer Monitoring Program Quality Assurance Program Plan, version 4.3. October 2008. The author is the Morro Bay National Estuary Program).
QAPP Information Reference(s):
LOE ID:	26481
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	248
Number of Exceedances:	2
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Morro Bay Volunteer Monitoring Program data for Chorro Creek to determine beneficial use support and results are as follows: 2 of 248 samples exceed the criterion for pH.
Data Reference:	MBVMP Dissolved Oxygen, pH and Temperature data for Chorro Creek.
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Municipal and Domestic Supply Objectives, Section II.A.2.a states the following: The pH value shall neither be depressed below 6.5 or raised above 8.3.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 4 monitoring sites [ 310TWB-Chorro Creek at South Bay Blvd., 310CHO - Chorro Creek at the Highway 1 Bridge, 310CAN-Chorro Creek at Canet Road and 310CER - Chorro Creek at
Temporal Representation:	Data was collected over the time period June 2002-December 2006. Chorro Creek monitoring sites are monitored monthly by Morro Bay Volunteer Monitoring Program volunteers. This monitoring is ongoing.
Environmental Conditions:
QAPP Information:	USEPA approved QAPP (Morro Bay National Estuary Program's Volunteer Monitoring Program Quality Assurance Program Plan, version 4.3. October 2008. The author is the Morro Bay National Estuary Program).
QAPP Information Reference(s):

DECISION ID	12232
Pollutant:	Escherichia coli (E. Coli)
Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	Agriculture | Grazing-Related Sources | Natural Sources | Urban Runoff/Storm Sewers
TMDL Name:	Morro Bay Pathogens
TMDL Project Code:	22
Date TMDL Approved by USEPA:	01/20/2004
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. The Morro Bay Pathogen TMDL (Including Chorro and Los Osos Creek) was approved by the USEPA on January 20, 2004. Five lines of evidence are available in the administrative record to assess this pollutant. Thirty-six of 143 samples Evaluation Guideline (USEPA Ambient Water Quality Criteria for Bacteria, 1986) as it applies to the Water Contact Recreation beneficial use. One of the 27 samples exceed the water quality objective for Non-Contact Recreation. These data represent monitoring from 4 sites along Chorro Creek. However, E. coli levels are lower at the South Bay Boulevard monitoring site (310TWB). This is the lowest site in the watershed and is located just above the estuary. Both CCAMP data and data collected by the Morro Bay Volunteer Monitoring Program (VMP) support this finding. The following is a summary of monitoring data collected only at 310TWB: CCAMP results from 310TWB - 4 of 27 samples exceed the Evaluation Guideline (USEPA Ambient Water Quality Criteria for Bacteria, 1986) as it applies to the Water Contact Recreation beneficial use. Morro Bay VMP results from 310TWB - 2 of 17 samples Evaluation Guideline (USEPA Ambient Water Quality Criteria for Bacteria, 1986) as it applies to the Water Contact Recreation beneficial use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Thirty-six of 143 samples Evaluation Guideline (USEPA Ambient Water Quality Criteria for Bacteria, 1986) as it applies to the Water Contact Recreation beneficial use and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12232

LOE ID:	18517
Pollutant:	Escherichia coli (E. Coli)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Non-Contact Recreation
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Escherichia coli.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml. E. coli is a fecal coliform.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/1/2004-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	18516
Pollutant:	Escherichia coli (E. Coli)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Water Contact Recreation
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 2 samples exceed the criterion for Escherichia coli.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	USEPA Ambient Water Quality Criteria for Bacteria -1986.
Objective/Criterion Reference:	Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Evaluation Guideline:	Single sample maximum allowable density for E. coli in freshwater is 235 MPN/100mL (as stated in Table 4, page 15)
Guideline Reference:	Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/1/2004-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	11671
Pollutant:	Escherichia coli (E. Coli)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Water Contact Recreation
Number of Samples:	25
Number of Exceedances:	3
Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 3 of 25 samples exceed the criterion for Escherichia coli.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	USEPA Ambient Water Quality Criteria for Bacteria -1986.
Objective/Criterion Reference:	Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Evaluation Guideline:	Single sample maximum allowable density for E. coli in freshwater is 235 MPN/100mL (as stated in Table 4, page 15)
Guideline Reference:	Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 1/10/2005-11/15/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	11672
Pollutant:	Escherichia coli (E. Coli)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Non-Contact Recreation
Number of Samples:	25
Number of Exceedances:	1
Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 25 samples exceed the criterion for Escherichia coli.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml. E. coli is a fecal coliform.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 1/10/2005-11/15/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	26517
Pollutant:	Escherichia coli (E. Coli)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Water Contact Recreation
Number of Samples:	116
Number of Exceedances:	32
Data and Information Type:	PATHOGEN MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Morro Bay Volunteer Monitoring Program data for Chorro Creek to determine beneficial use support and results are as follows: 32 of 116 samples exceed the Evaluation Guideline for E. coli.
Data Reference:	Final_Data_MBVMP_Bacteria_for_Chorro_Creek
Water Quality Objective/Criterion:	USEPA Ambient Water Quality Criteria for Bacteria -1986.
Objective/Criterion Reference:	Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Evaluation Guideline:	Single sample maximum allowable density for E. coli in freshwater is 235 MPN/100mL (as stated in Table 4, page 15).
Guideline Reference:	Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Spatial Representation:	Staff and volunteer working with the Morro Bay Volunteer Monitoring PRogram collected data from four monitoring sites (310TWB - Chorro Creek at South Bay Blvd, 310CAN - Chorro Creek at Cannet Road, 310CER - Chorro Creek Ecological Reserve, in between Gilardi road and Canet Road and 310CHO - Chorro Creek at Highway 1).
Temporal Representation:	Data was collected (approxinately monthly) between August 2002 and December 2006.
Environmental Conditions:
QAPP Information:	USEPA approved QAPP (Morro Bay National Estuary Program's Volunteer Monitoring Program Quality Assurance Program Plan, version 4.3. October 2008. The author is the Morro Bay National Estuary Program).
QAPP Information Reference(s):

DECISION ID	5987
Pollutant:	Nutrients
Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2006)
Revision Status	Revised
Sources:	Agriculture | Major Municipal Point Source-dry and/or wet weather discharge
TMDL Name:	Chorro Creek Nutrients and Dissolved Oxygen
TMDL Project Code:	618
Date TMDL Approved by USEPA:	07/17/2007
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. A TMDL for Nutrients and Dissolved Oxygen in Chorro Creek was approved July 19, 2007 by USEPA to achieve the narrative water quality objective for biostimulatory substances. The TMDL requires that the median nitrate-N concentration not exceed 1.5 mg/L-N within the half-mile reach of Chorro Creek measured upstream from the road crossing at South Bay Boulevard. The median is measured as a rolling median of data collected between May through September at this location. Nitrate-N concentration in Chorro Creek is supportive of the MUN beneficial use. Thus, Chorro Creek is not impaired for nitrate-N, but nitrate-N concentrations are contributing to exceedances of the biostimulatory objective, which in turn contributes to exceedances of the dissolved oxygen objective. Eleven lines of evidence (LOEs) are available in the administrative record to assess these pollutants for nutrients. One LOE (LOE #3940) is a placeholder that does not contain data or information. Staff are unable to reconstruct the original data used to place this water segment-pollutant combination on the section 303(d) list. Seven lines of evidence are available in the administrative record to assess this pollutant for Municipal and Domestic Supply. None of the 78 nitrate samples exceed water quality objectives for either Municipal and Domestic Supply or Agricultural Supply. Only 1 of the 12 Nitrate+Nitrite samples exceed the OEHHA Public Health Goal in Drinking Water (December 1997) as it applies to the Municipal and Domestic Supply beneficial use. Nitrate samples from LOE #25329 are compared to the TMDL numeric target. The numeric target meets the criteria of the Listing Policy (Section 6.1.3) as it is applicable to the beneficial use, protective of the beneficial use, linked to the pollutant under consideration, scientifically based and peer reviewed, well described and identified at a range above which negative impacts will occur. Twenty-one of the 24 nitrate samples exceed the TMDL (evaluated as a rolling median of data collected between May through September from the half-mile reach upstream of South Bay Boulevard). Similarly, ortho-phosphate data summarized in LOE #25331 are compared to the TMDL numeric target. Thirty-five of 59 ortho-phosphate samples exceed the TMDL (again evaluated as a rolling median of data collected between May through September from the half-mile reach upstream of South Bay Boulevard). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Twenty-one of 24 nitrate samples exceed the TMDL for Nitrate and 35 of 59 ortho-phosphate samples exceed the TMDL. Each of these exceeds the allowable frequency calculated from the equation in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant, developed in the Chorro Creek Nutrient TMDL (July, 2007), are being exceeded.
SWRCB Board Decision / Staff Recommendation:	N/A
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 5987

LOE ID:	25329
Pollutant:	Nitrogen, Nitrate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Fish Migration | Fish Spawning | Preservation of Rare & Endangered Species | Warm Freshwater Habitat | Wildlife Habitat
Number of Samples:	24
Number of Exceedances:	21
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	CCAMP monitoring data collected data monthly between April 2001 and December 2006 (with the exception of April 2004 – December 2004) from a single site (Chorro Creek at South Bay Boulevard, 310TWB) was used to determine if the TMDL is being met. Only data collected between the months of May and September were used in this assessment. Twenty-one of the 24 samples, as well as the median value, exceed the TMDL.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause a nuisance or adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin, Chapter 3, Section II.A.2.a, General Objectives).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	The following TMDL is established in the Total Maximum Daily Load for Nutrients and Dissolved Oxygen in Chorro Creek,San Luis Obispo County, California (Approved July 19, 2007 by USEPA) to achieve the narrative water quality objective for biostimulatory substances. Median nitrate-N concentration shall not exceed 1.5 mg/L-N within the half-mile reach of Chorro Creek, measured upstream from the road crossing at South Bay Boulevard. The median is measured as a rolling median from May through September.
Guideline Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Spatial Representation:	Regional Board staff analyzed monitoring data from one site (Chorro Creek at South Bay Boulevard, 310TWB) in this assessment.
Temporal Representation:	CCAMP staff collected monitoring data monthly between April 2001 and December 2006 (with the exception of April 2004 – December 2004).
Environmental Conditions:
QAPP Information:	SWAMP QAPP (Puckett et al., 2002)
QAPP Information Reference(s):
LOE ID:	25331
Pollutant:	Orthophosphate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Fish Migration | Fish Spawning | Preservation of Rare & Endangered Species | Warm Freshwater Habitat | Wildlife Habitat
Number of Samples:	59
Number of Exceedances:	35
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	CCAMP monitoring data collected data monthly between April 2001 and December 2006 (with the exception of April 2004 – December 2004) from a single site (Chorro Creek at South Bay Boulevard, 310TWB) was used to determine if the TMDL is being met.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause a nuisance or adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin, Chapter 3, Section II.A.2.a, General Objectives).
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:	The following TMDL is established in the Total Maximum Daily Load for Nutrients and Dissolved Oxygen in Chorro Creek, San Luis Obispo County, California (Approved July 19, 2007 by USEPA) to achieve the narrative water quality objective for biostimulatory substances. Median orthophosphorus-P concentration shall not exceed 0.4 mg/L-P within the half-mile reach of Chorro Creek, measured upstream from the road crossing at South Bay Boulevard.
Guideline Reference:	Region 3 TMDL reports, plans and data for multiple waterbodies. San Luis Obispo, CA: Central Coast RWQCB. https://www.waterboards.ca.gov/central coast/TMDL/303dand TMDLprojects.htm
Spatial Representation:	Regional Board staff analyzed monitoring data from one site (Chorro Creek at South Bay Boulevard, 310TWB) in this assessment.
Temporal Representation:	CCAMP staff collected monitoring data monthly between April 2001 and December 2006 (with the exception of April 2004 – December 2004).
Environmental Conditions:
QAPP Information:	SWAMP QAPP (Puckett et al, 2002)
QAPP Information Reference(s):
LOE ID:	18413
Pollutant:	Nitrate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Nitrate as N.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin Objective for municipal and domestic supply uses of inland surface waters (Section II.A.2) states the following: waters shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Article 4, Chapter 15, Section 64435, Tables 2 and 3 as listed in Table 3-2. The maximum contaminant level listed in Table 3-2 (inorganic and fluoride concentrations not to be exceeded in domestic or municipal supply) for nitrate is 10.0 mg/L (NO3 as N).
Objective/Criterion Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/17/2003-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	9992
Pollutant:	Nitrate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	59
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 59 samples exceed the criterion for Nitrate as N.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when nitrate exceeds 30 mg/L NO3 as N in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	9949
Pollutant:	Nitrate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	16
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 16 samples exceed the criterion for Nitrate as N.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin Objective for municipal and domestic supply uses of inland surface waters (Section II.A.2) states the following: waters shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Article 4, Chapter 15, Section 64435, Tables 2 and 3 as listed in Table 3-2. The maximum contaminant level listed in Table 3-2 (inorganic and fluoride concentrations not to be exceeded in domestic or municipal supply) for nitrate is 10.0 mg/L (NO3 as N).
Objective/Criterion Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	9936
Pollutant:	Nitrate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	16
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Santa Lucia (SantaLucia) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 16 samples exceed the criterion for Nitrate as N.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when nitrate exceeds 30 mg/L NO3 as N in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CAN-Chorro Creek at Canet Road]
Temporal Representation:	Data was collected over the time period 1/16/2002-3/4/2003. Santa Lucia Coast is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	10005
Pollutant:	Nitrate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	59
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCAMP Coastal Confluences (CC) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 59 samples exceed the criterion for Nitrate as N.
Data Reference:	Final Data File used for assessment: CCAMP Water Quality Data_file1
	Final Data File used for assessment: CCAMP Water Quality Data_file2
	Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion:	The Water Quality Control Plan, Central Coast Basin Objective for municipal and domestic supply uses of inland surface waters (Section II.A.2) states the following: waters shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Article 4, Chapter 15, Section 64435, Tables 2 and 3 as listed in Table 3-2. The maximum contaminant level listed in Table 3-2 (inorganic and fluoride concentrations not to be exceeded in domestic or municipal supply) for nitrate is 10.0 mg/L (NO3 as N).
Objective/Criterion Reference:	Title 22, Division 4, Ch. 15, Article 4, Section 64431, Table 64431-A
	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310TWB-Chorro Creek at South Bay Boulevard]
Temporal Representation:	Data was collected over the time period 4/24/2001-12/20/2006. CCAMP Coastal confluence monitoring is conducted monthly (with the exception of April 2003 - December 2003) and is ongoing.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID:	18412
Pollutant:	Nitrate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Agricultural Supply
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Chorro Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Nitrate as N.
Data Reference:	Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion:	Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when nitrate exceeds 30 mg/L NO3 as N in irrigation supply water.
Objective/Criterion Reference:	Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310-UCF-41 - Upper Chorro Flats]
Temporal Representation:	Data was collected over the time period 5/17/2003-5/7/2005. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID:	3940
Pollutant:	Nutrients
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	0
Number of Exceedances:	0
Data and Information Type:	Not Specified
Data Used to Assess Water Quality:	Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference:	Placeholder reference pre-2006 303(d)
Water Quality Objective/Criterion:	Unspecified
Objective/Criterion Reference:	Placeholder reference pre-2006 303(d)
Evaluation Guideline:	Unspecified
Guideline Reference:	Placeholder reference pre-2006 303(d)
Spatial Representation:	Unspecified
Temporal Representation:	Unspecified
Environmental Conditions:	Unspecified
QAPP Information:	Unspecified
QAPP Information Reference(s):
LOE ID:	15248
Pollutant:	Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Municipal & Domestic Supply
Number of Samples:	12
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Central Coast Regional Board Staff assessed CCWQP Southern Area Ag-Waiver Monitoring (R3_CMPSouth) data for Chorro Creek to determine beneficial use support and results are as follows: 1 of 12 samples exceed the criterion for Nitrate/Nitrite as N.
Data Reference:	Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data
	Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data
Water Quality Objective/Criterion:	OEHHA public Health Goals for Nitrate and Nitrogen in Drinking Water (December 1997). Page 6.
Objective/Criterion Reference:	Public health goals for nitrate and nitrite in drinking water
Evaluation Guideline:	OEHHA Public Health Goal states that sum of the concentration of nitrate + nitrite shall not exceed 10 mg/L (NO3+NO2 expressed as N).
Guideline Reference:	Public health goals for nitrate and nitrite in drinking water
Spatial Representation:	Data for this line of evidence for Chorro Creek was collected at 1 monitoring site [ 310CCC - Chorro Creek up stream from Chorro Flats]
Temporal Representation:	Data was collected over the time period 1/26/2006-12/14/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).
Environmental Conditions:	Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information:	All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID	4242
Pollutant:	Sedimentation/Siltation
Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2006)
Revision Status	Original
Sources:	Agriculture | Agriculture-storm runoff | Channel Erosion | Channelization | Construction/Land Development | Erosion/Siltation | Golf course activities | Hydromodification | Irrigated Crop Production | Natural Sources | Nonpoint Source | Range Grazing-Riparian and/or Upland | Range Grazing-Upland | Resource Extraction | Road Construction | Streambank Modification/Destabilization
TMDL Name:	Morro Bay Sediment
TMDL Project Code:	242
Date TMDL Approved by USEPA:	01/20/2004
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for listing under section 2.2 of the Listing Policy. Under this section of the Policy, a minimum of one line of evidence is needed to assess listing status. The Morro Bay Sediment TMDL was approved by RWQCB on May 16, 2003 and subsequently approved by USEPA on January 20, 2004. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination in the Water Quality Limited Segments Being Addressed portion of the section 303(d) list.
RWQCB Board Decision / Staff Recommendation:	No new data were assessed for 2008. The decision has not changed.
SWRCB Board Decision / Staff Recommendation:	After review of the available data and information for this recommendation, SWRCB staff conclude that the water body should be placed in the Water Quality Limited Segments Being Addressed category of the section 303(d) list because a TMDL has been approved by USEPA and an implementation plan has been approved.
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 4242

LOE ID:	1900
Pollutant:	Sedimentation/Siltation
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	0
Number of Exceedances:	0
Data and Information Type:	Not Specified
Data Used to Assess Water Quality:	Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference:	Placeholder reference 2006 303(d)
Water Quality Objective/Criterion:
Objective/Criterion Reference:
Evaluation Guideline:
Guideline Reference:
Spatial Representation:
Temporal Representation:
Environmental Conditions:
QAPP Information:	QA Info Missing
QAPP Information Reference(s):