Final California 2020 Integrated Report (303(d) List/305(b) Report)

SWAMP Data:

Non-SWAMP

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):

Line of Evidence (LOE) for Decision ID 99525, Ammonia	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

94376

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Surface water shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Evaluation Guideline:

Aquatic Life Ambient Water Quality Criteria for Ammonia ? Freshwater (USEPA 2013): the 30-day rolling average concentration (criterion continuous concentration or CCC) of total ammonia nitrogen(in mg TAN/L) in freshwater are not to be exceeded more than once every three years on average. The CCC values are based on pH and temperature. The CCC formula is found on page 46 and the table of CCC values is on page 49.

Guideline Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Spatial Representation:

Data for this line of evidence for Calleguas Creek Reach 12 (was Conejo Creek/Arroyo Conejo North Fork on 1998 303d list) was collected at 1 monitoring site [ North Fork Arroyo Conejo Random Site 36 - 408BA0036]

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	70499	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Chlordane (tissue)
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Nonpoint Source
TMDL Name:	Calleguas Creek Historic Pesticides (5)
TMDL Project Code:	358
Date TMDL Approved by USEPA:	03/14/2006
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal on the CWA section 303(d) List under sections 2.2 and 4.1 of the Listing Policy. Under 4.1 of the Policy, a minimum of one line of evidence is needed to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. One placeholder decision for a CWA section 303(d) Listing made in a previous assessment cycle exceed the objective. Zero of 21 samples exceed the objective. 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 CWA section 303(d) List. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. 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 placeholder decision and zero of 21 samples exceeded the objective and these exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4. The Calleguas Creek Historic Pesticides TMDL was approved by USEPA on 03/14/2006. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 70499, Chlordane (tissue)	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83485

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 21 samples exceeded the water quality criteria/objective. Chlordane, alpha-chlordane, gamma-chlordane, Heptachlor, Heptachlor Epoxide, cis-and trans Nonachlor and Oxychlordane results were added to assess this waterbody. Results were evaluated against Chlordane value.

Data Reference:

Data for Various Pollutants in Ventura County, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. Waters shall not contain substances in concentrations that result in the deposition of material that causes nuisance or adversely affects beneficial uses. (Water Quality Control Plan for the Coastal Watersheds of Los Angeles And Ventura Counties).

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The CTR CCC for Chlordane is 0.0043 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

The 21 samples were collected at Calleguas Creek at University Drive, North Fork Arroyo Conejo (tributary to Conejo Creek)at sampling location Thousand Oaks-1.

Temporal Representation:

Water samples were collected in 2006 (one sample), in 2007 ( 6 samples), in 2008 (6 samples), in 2009 ( 6 samples), and in 2010 ( 2 samples).

Environmental Conditions:

There was no special environmental condition reported.

QAPP Information:

Samples were collected and analyzed in accordance to Ventrua County Agricultural Irrigated Land Group (VCAILG) Quality Assurance Project Plan (QAPP) dated Augus 3, 2006.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 70499, Chlordane (tissue)	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

2189

Pollutant:

Chlordane (tissue)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

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:

Data for Various Pollutants in Ventura County, 2006-2009.

SWAMP Data:

Non-SWAMP

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	70680	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	DDT (tissue)
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Nonpoint Source
TMDL Name:	Calleguas Creek Historic Pesticides (5)
TMDL Project Code:	358
Date TMDL Approved by USEPA:	03/14/2006
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.5 of the Listing Policy. Under section 4.5 a single line of evidence is necessary to assess listing status. 2 lines of evidence are available in the administrative record to assess pollutant. 10 of 21 samples exceeded the GUIDELINE. 0 of 0 samples exceeded the GUIDELINE. 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 CWA 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. 10 of 21 and 0 of 0 samples exceeded the GUIDELINE and this exceeds the allowable frequency listed 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 70680, DDT (tissue)	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83497

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Ten of the 21 sample exceeded the water quality evaluation guideline. Results of 2,4,DDD, 2,4,DDE, 2,4,DDT, 4,4, DDD, 4,4,DDE, and 4,4,DDT were added to assess water quality against DDT criteria.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan states "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxics Rule Criteria Freshwater Aquatic Life Protection Continuous Concentration (4-day Average)criteria is 0.001 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Twenty-one samples were collected at Calleguas Creek at University Drive, North Fork Arroyo Conejo (tributary to Conejo Creek)at sampling location Thousand Oaks-1.

Temporal Representation:

Water samples were collected in 2006 (one sample), in 2007 (6 samples), in 2008 (6 samples), in 2009 (6 samples) and in 2010 (two samples).

Environmental Conditions:

There was no special environmental condition reported.

QAPP Information:

Samples were collected and analyzed in accordance to Ventrua County Agricultural Irrigated Land Group (VCAILG) Quality Assurance Project Plan (QAPP) dated Augus 3, 2006.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 70680, DDT (tissue)	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

2190

Pollutant:

DDT (tissue)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Not Recorded

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

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:

SWAMP Data:

Non-SWAMP

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	89773	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Sulfates
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Atmospheric Deposition \| Domestic Use of Ground Water \| Groundwater Loadings \| Irrigated Crop Production \| Major Municipal Point Source-dry weather discharge \| Surface Runoff
TMDL Name:	Calleguas Creek Boron/Sulfate/TDS (4)
TMDL Project Code:	357
Date TMDL Approved by USEPA:	12/02/2008
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 4.2 of the Listing Policy. Under section 4.2 a single line of evidence are necessary to assess listing status. 3 lines of evidence are available in the administrative record to assess this pollutant. 0 of the 0 samples exceeded the OBJECTIVE. 1 of the 1 samples exceeded the OBJECTIVE. 0 of the 0 samples exceeded the OBJECTIVE. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for removing this water segment-pollutant combination from the CWA 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. 0 of 0, 1 of 1, and 0 of 0 samples exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using table 4.2. 4. Pursuant to SECTION 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 89773, Sulfates	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

4074

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

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:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Unspecified

Objective/Criterion Reference:

Evaluation Guideline:

Unspecified

Guideline Reference:

Spatial Representation:

Unspecified

Temporal Representation:

Unspecified

Environmental Conditions:

Unspecified

QAPP Information:

Unspecified

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 89773, Sulfates	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83536

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Table 3-8 of The Water Quality Control Plan for the Los Angeles Region specifies the Sulfate objective for the Calleguas Creek Reach 12 (was Conejo Creek/Arroyo Conejo North Fork on 1998 303d list) within the Calleguas-Conejo Creek watershed's Above Portrero Road reach boundary as 250 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 89773, Sulfates	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

28040

Pollutant:

Sulfates

LOE Subgroup:

Narrative Description Data

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

A TMDL has been approved for this water segment-pollutant combination. The Calleguas Creek Watershed Salts TMDL was adopted by the Los Angeles RWQCB on October 04, 2007 and subsequently approved by USEPA. The TMDL was integrated into the Basin Plan as Attachment A of Regional Board Resolution No. 2007-016.

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QA information unavailable.

QAPP Information Reference(s):


DECISION ID	69012	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Total Dissolved Solids
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Atmospheric Deposition \| Domestic Use of Ground Water \| Groundwater Loadings \| Irrigated Crop Production \| Major Municipal Point Source-dry weather discharge \| Surface Runoff
TMDL Name:	Calleguas Creek Boron/Sulfate/TDS (4)
TMDL Project Code:	357
Date TMDL Approved by USEPA:	12/02/2008
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 4.2 of the Listing Policy. Under section 4.2 a single line of evidence are necessary to assess listing status. 4 lines of evidence are available in the administrative record to assess this pollutant. 1 of the 1 samples exceeded the OBJECTIVE. 0 of the 0 samples exceeded the OBJECTIVE. 0 of the 0 samples exceeded the OBJECTIVE. 1 of the 1 samples exceeded the OBJECTIVE. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for removing this water segment-pollutant combination from the CWA 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. 1 of 1, 0 of 0, 0 of 0, and 1 of 1 samples exceeded the OBJECTIVE and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using table 4.2. 4. Pursuant to SECTION 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 69012, Total Dissolved Solids	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83543

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The sample collected exceeded the objective.

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Table 3-8 states that the Total Dissolved Solids maximum concentration objective Above Potrero Rd. in the Calleguas Creek watershed is 850 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The sample was collected from the North Fork Arroyo Conejo Random Site 36 station (408BA0036).

Temporal Representation:

The sample was collected on 5/5/2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 69012, Total Dissolved Solids	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

4075

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

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:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Unspecified

Objective/Criterion Reference:

Evaluation Guideline:

Unspecified

Guideline Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Spatial Representation:

Unspecified

Temporal Representation:

Unspecified

Environmental Conditions:

Unspecified

QAPP Information:

Unspecified

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 69012, Total Dissolved Solids	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

28041

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Narrative Description Data

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

A TMDL has been approved for this water segment-pollutant combination. The Calleguas Creek Watershed Salts TMDL was adopted by the Los Angeles on October 04, 2007 and subsequently approved by USEPA. The TMDL was integrated into the Basin Plan as Attachment A of Regional Board Resolution No. 2007-016.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QA information unavailable.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 69012, Total Dissolved Solids	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83539

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Table 3-8 of The Water Quality Control Plan for the Los Angeles Region specifies the Dissolved Solids objective for the Calleguas Creek Reach 12 (was Conejo Creek/Arroyo Conejo North Fork on 1998 303d list) within the Calleguas-Conejo Creek watershed's Above Portrero Road reach boundary as 850 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	68995	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Toxaphene
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	A Source Unknown
TMDL Name:	Calleguas Creek Historic Pesticides (5)
TMDL Project Code:	358
Date TMDL Approved by USEPA:	03/14/2006
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal on the CWA section 303(d) List under sections 2.2 and 3.1 of the Listing Policy. Under SECTION 3.1 of the Policy, a minimum of one line of evidence is needed to assess listing status. 2 lines of evidence are available in the administrative record to assess this pollutant. 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 CWA section 303(d) List. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. 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. 5 of 21 samples exceeded the OBJECTIVE and these exceed the allowable frequency listed in Table 3.1of the Listing Policy. 4. The Calleguas Creek Historic Pesticides was approved by USEPA on 03/14/2006. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 68995, Toxaphene	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

2193

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Not Recorded

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Unspecified--This LOE is a placeholder to support a listing decision made by USEPA for 2006.

Data Reference:

Data for Various Pollutants in Ventura County, 2006-2009.

SWAMP Data:

Non-SWAMP

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):

Line of Evidence (LOE) for Decision ID 68995, Toxaphene	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83544

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

5 of the 21 samples exceeded the water quality criteria/objective.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Criteria Continuous Concentration (4-day Average) is 0.0002 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Twenty-one samples were collected at Calleguas Creek at University Drive, North Fork Arroyo Conejo (tributary to Conejo Creek)at sampling location Thousand Oaks-1.

Temporal Representation:

Water samples were collected in 2006 (one sample), in 2007 (6 samples), in 2008 (6 samples), in 2009 (6 samples) and in 2010 (two samples).

Environmental Conditions:

There was no special environmental condition reported.

QAPP Information:

Samples were collected and analyzed in accordance to Ventrua County Agricultural Irrigated Land Group (VCAILG) Quality Assurance Project Plan (QAPP) dated Augus 3, 2006.

QAPP Information Reference(s):


DECISION ID	94304	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Alkalinity as CaCO3
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the OBJECTIVE. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA 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. 0 of 1 sample exceeded the OBJECTIVE and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using table 3.2. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94304, Alkalinity as CaCO3	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83465

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

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, Colorado River Basin).

Objective/Criterion Reference:

Evaluation Guideline:

The Alkalinity as CaCO3 criteria for the protection of freshwater aquatic life is 20000 ug/L (National Recommended Water Quality Criteria, 2009).

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	95004	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Aluminum
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 2 lines of evidence are available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. 2 of 36 samples exceeded the CRITERIA. 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 CWA 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. 0 of 1 and 2 of 36 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95004, Aluminum	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83466

Pollutant:

Aluminum

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Surface water shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Evaluation Guideline:

The National Recommended Water Quality Critiera for the protection of aquatic life from aluminum is the chronic continuous concentration (expressed as a 4-day average) of 87 ug/L.

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 95004, Aluminum	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83470

Pollutant:

Aluminum

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Two of the 36 samples exceeded the evaluation guideline.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations are intended protect aquatic organisms from chronic exposures (expressed as 4-day average concentration) in freshwater. The evaluation guideline for aluminum is 87 ug/L to protect warm freshwater habitat.

Guideline Reference:

Spatial Representation:

R-1 is the upstream of the discharge (Hill Canyon WWTP) sample site (Latitude (N) 34.21332, Longitude (W) 118.92149 and elev. at 87 m). R-2 is downstream (Latitude (N) 34.21139, Longitude (W) 118.92329 and elev. at 84m) of our discharge and consists of effluent and the water flowing from sample site R-1.

Temporal Representation:

Samples are collected quarterly during the months of February, May, August, and November. Semi-annual sampling events in February and August, and an annual event takes place in August. The data analyzed is for data collected from August 2007 through March of 2011.

Environmental Conditions:

Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West).

QAPP Information:

Samples are collected and analyzed in accordance with the City of Thousand Oaks Hill Canyon Wastewater Treatment Plant (Hill Canyon WWTP)located in Camarillo, to North Fork Arroyo Conejo, a water of the United States. The discharge is regulated under waste discharge requirements contained in Order No. 96-044, adopted by this Regional Board on June 10, 1996. Order No. 96-044 also serves as a permit under the National Pollutant Discharge Elimination System (NPDES No.CA0056294).

QAPP Information Reference(s):


DECISION ID	95005	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Arsenic
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 2 lines of evidence are available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. 0 of 36 samples exceeded the CRITERIA. 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 CWA 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. 0 of 1 and 0 of 36 samples exceeded the CRITERIA 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.

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95005, Arsenic	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83474

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 36 samples exceeded the evaluation guideline.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The CTR for arsenic is 150 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Temporal Representation:

Environmental Conditions:

Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West).

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 95005, Arsenic	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83473

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for dissolved arsenic is 0.150 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94366	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Azinphos-methyl (Guthion)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA 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. 0 of 1 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94366, Azinphos-methyl (Guthion)	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83479

Pollutant:

Azinphos-methyl (Guthion)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 4 samples exceeded the water quality evaluation guideline criteria.

Data Reference:

Data for Various Pollutants in Ventura County, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan states "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA National Recommended Criteria 4-day Criterion Continuous Concentration for Guthion in freshwater is 0.01 ug/L.

Guideline Reference:

Spatial Representation:

The four samples were collected at Calleguas Creek at University Drive, North Fork Arroyo Conejo (tributary to Conejo Creek)at sampling location Thousand Oaks-1.

Temporal Representation:

Water samples were collected in 2009 (10/14/2009 & 12/08/2009) and in 2010 (2/22/2010 & 3/18/2010).

Environmental Conditions:

There was no special environmental condition reported.

QAPP Information:

Samples were collected and analyzed in accordance to Ventrua County Agricultural Irrigated Land Group (VCAILG) Quality Assurance Project Plan (QAPP) dated Augus 3, 2006.

QAPP Information Reference(s):


DECISION ID	98467	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Benthic Community Effects
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Benthic Community Effects is being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, an additional line of evidence associating the Benthic Community Effects with a water or sediment concentration of pollutants is necessary to assess listing status. The CSCI score for this site is below the 0.79 threshold. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing Benthic Community Effects in this water segment on the CWA 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. The CSCI score for this site is below the 0.79 threshold indicating poor water quality for this area but this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 2 samples is needed to determine impairment using Table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. The CSCI is applicable statewide, accounts for a much wider range of natural variability, and provides equivalent scoring thresholds in all regions of the state. The CSCI will be used in the future for water quality assessment purposes statewide over the regional indices of biologic integrity (IBIs).

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:	The CSCI is applicable statewide, accounts for a much wider range of natural variability, and provides equivalent scoring thresholds in all regions of the state. The CSCI will be used in the future for water quality assessment purposes statewide over the regional indices of biologic integrity (IBIs).

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 98467, Benthic Community Effects	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

95282

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

The CSCI score for this site is below the 0.79 threshold, and is therefore exceeding the water quality objective for the aquatic life beneficial use.

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.

Objective/Criterion Reference:

Evaluation Guideline:

The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rhen, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.

Guideline Reference:

Bioassessment in complex environments: designing an index for consistent meaning in different settings

Spatial Representation:

The sample was collected from North Fork Arroyo Conejo Random Site 36.

Temporal Representation:

The sample was collected in May 2008.

Environmental Conditions:

QAPP Information:

Samples were collected for the SWAMP RWB4 Stormwater Monitoring Council CY 2008 following SWAMP protocols and stored in the SWAMP database.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94365	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Bifenthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA 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. 0 of 1 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94365, Bifenthrin	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83480

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Bifenthrin does not exceed 0.0006 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	95006	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Cadmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 2 lines of evidence are available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. 0 of 36 samples exceeded the CRITERIA. 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 CWA 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. 0 of 1 and 0 of 36 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 95006, Cadmium	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83484

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 36 samples exceeded the evaluation guideline.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion. If no hardness data were available, a value of 100 mg/L was used.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Temporal Representation:

Environmental Conditions:

Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West).

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 95006, Cadmium	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83481

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94534	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Chromium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 3 lines of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. 0 of 12 samples exceeded the CRITERIA. 0 of 36 samples exceeded the CRITERIA. 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 CWA 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. 0 of 1, 0 of 12, 0 of 36 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94534, Chromium	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83488

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 12 samples exceeded the evaluation guideline.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Temporal Representation:

Environmental Conditions:

Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West).

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 94534, Chromium	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83489

Pollutant:

Chromium, hexavalent

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 36 samples exceeded the evaluation guideline.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The CTR for hexavalent chromium is 11 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Temporal Representation:

Environmental Conditions:

Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West).

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 94534, Chromium	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83487

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	100406	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Chromium, hexavalent
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 36 samples exceeded the CRITERIA. 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 CWA 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. 0 of 36 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 100406, Chromium, hexavalent	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83489

Pollutant:

Chromium, hexavalent

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 36 samples exceeded the evaluation guideline.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The CTR for hexavalent chromium is 11 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Temporal Representation:

Environmental Conditions:

Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West).

QAPP Information:

QAPP Information Reference(s):


DECISION ID	94180	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Copper
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 2 lines of evidence are available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. 3 of 108 samples exceeded the CRITERIA. 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 CWA 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. 0 of 1 and 3 of 108 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94180, Copper	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83490

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

108

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Three of the 108 samples exceeded the evaluation guideline.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Temporal Representation:

Samples are collected monthly from August 2007 through March of 2011.

Environmental Conditions:

Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West).

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 94180, Copper	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83491

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94417	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Cyhalothrin, Lambda
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA 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. 0 of 1 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94417, Cyhalothrin, Lambda	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83493

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Surface water shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Cyhalothrin, lambda, total does not exceed 0.0005 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94418	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Cypermethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA 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. 0 of 1 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94418, Cypermethrin	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83496

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The interim freshwater criterion maximum concentration is 0.002 ug/L (DFG 00-6, 2000).

Guideline Reference:

Sacramento River Water Sampling Data for 303(d) Listing/Delisting Process. Letter W-101-200-000 and data files

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94419	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Deltamethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA 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. 0 of 1 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94419, Deltamethrin	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83498

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Deltamethrin is the maximum acceptable toxicant concentration (MATC) of 0.02 ug/L.

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94245	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Endosulfan
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 21 samples exceeded the CRITERIA. 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 CWA 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. 0 of 21 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94245, Endosulfan	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83500

Pollutant:

Endosulfan

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 21 samples exceeded the water quality evaluation guideline criteria. Results of Endosulfan I and Endosulfan II were added for assessment. Results were evaluated against Endosufan I criteria value.

Data Reference:

Data for Various Pollutants in Ventura County, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan states "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxic Rule criteria fresh aquatic life protection continuous concentration (4-day average)is 0.056 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Twenty-one samples were collected at Calleguas Creek at University Drive, North Fork Arroyo Conejo (tributary to Conejo Creek)at sampling location Thousand Oaks-1.

Temporal Representation:

Water samples were collected in 2006 (one sample), 2007 (6 samples), 2008 (6 samples), 2009 (6 samples) and in 2010 (two samples).

Environmental Conditions:

There was no special environmental condition reported.

QAPP Information:

Samples were collected and analyzed in accordance to Ventrua County Agricultural Irrigated Land Group (VCAILG) Quality Assurance Project Plan (QAPP) dated Augus 3, 2006.

QAPP Information Reference(s):


DECISION ID	94420	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Esfenvalerate/Fenvalerate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA 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. 0 of 1 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94420, Esfenvalerate/Fenvalerate	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83502

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.13 ug/L, as determined in a 96 hour toxicity test using the fathead minnow, Pimephales promelas. (USEPA OPP Ecotoxicity database)

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94472	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Fenpropathrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA 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. 0 of 1 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94472, Fenpropathrin	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83503

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the median lethal concentration (LC50; 2.2 ug/L).

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94302	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Heptachlor epoxide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 21 samples exceeded the CRITERIA. 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 CWA 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. 0 of 21 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94302, Heptachlor epoxide	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83507

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 21 samples exceeded the water quality criteria/objective.

Data Reference:

Data for Various Pollutants in Ventura County, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Region 4 Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxic Rule criteria fresh aquatic life protection continuous concentration (4-day average)is 0.0038 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Twenty-one samples were collected at Calleguas Creek at University Drive, North Fork Arroyo Conejo (tributary to Conejo Creek)at sampling location Thousand Oaks-1.

Temporal Representation:

Twenty-one water samples were collected in 2006 (one sample), in 2007 (6 samples), in 2008 (6 samples) 2009 (6 samples) and two samples in 2010 (2 samples).

Environmental Conditions:

There was no special environmental condition reported.

QAPP Information:

Samples were collected and analyzed in accordance to Ventrua County Agricultural Irrigated Land Group (VCAILG) Quality Assurance Project Plan (QAPP) dated Augus 3, 2006.

QAPP Information Reference(s):


DECISION ID	94181	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Iron
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 2 lines of evidence are available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. 0 of 36 samples exceeded the CRITERIA. 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 CWA 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. 0 of 1 and 0 of 36 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94181, Iron	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83508

Pollutant:

Iron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region, Tulare Lake Basin: waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations are intended protect aquatic organisms from chronic exposures (expressed as 4-day average concentration) in freshwater. The evaluation guideline for iron is 1,000 ug/L to protect warm freshwater habitat.

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 94181, Iron	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83510

Pollutant:

Iron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 36 samples exceeded the evaluation guideline.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations are intended protect aquatic organisms from chronic exposures (expressed as 4-day average concentration) in freshwater. The evaluation guideline for iron is 1,000 ug/L to protect warm freshwater habitat.

Guideline Reference:

Spatial Representation:

Temporal Representation:

Environmental Conditions:

Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West).

QAPP Information:

QAPP Information Reference(s):


DECISION ID	94182	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Lead
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 2 lines of evidence are available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. 0 of 36 samples exceeded the CRITERIA. 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 CWA 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. 0 of 1 and 0 of 36 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94182, Lead	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83457

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 36 samples exceeded the evaluation guideline.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations are intended protect aquatic organisms from chronic exposures (expressed as 4-day average concentration) in freshwater. The evaluation guideline for thallium is 20 ug/L to protect warm freshwater habitat.

Guideline Reference:

Spatial Representation:

Temporal Representation:

Environmental Conditions:

Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West).

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 94182, Lead	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83511

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94303	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Mercury
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 102 samples exceeded the CRITERIA. 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 CWA 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. 0 of 102 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94303, Mercury	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83460

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

102

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 102 samples exceeded the evaluation guideline.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations (4-day average concentrations) for freshwater aquatic organisms exposure to elemental mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

Temporal Representation:

Samples are collected monthly from August 2007 through March of 2011.

Environmental Conditions:

Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West).

QAPP Information:

QAPP Information Reference(s):


DECISION ID	94243	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Methyl Parathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 25 samples exceeded the CRITERIA. 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 CWA 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. 0 of 25 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94243, Methyl Parathion	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83461

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 21 samples exceeded the water quality evaluation guideline criteria.

Data Reference:

Data for Various Pollutants in Ventura County, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan states "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The Department of Fish and Game instantaneous criteria for Methyl parathion; parathion, methyl is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Spatial Representation:

Twenty-one samples were collected at Calleguas Creek at University Drive, North Fork Arroyo Conejo (tributary to Conejo Creek)at sampling location Thousand Oaks-1.

Temporal Representation:

Water samples were collected in 2006 (one sample), in 2007 (6 samples), in 2008 (6 samples), in 2009 (6 samples) and in 2010 (two samples).

Environmental Conditions:

There was no special environmental condition reported.

QAPP Information:

Samples were collected and analyzed in accordance to Ventrua County Agricultural Irrigated Land Group (VCAILG) Quality Assurance Project Plan (QAPP) dated Augus 3, 2006.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 94243, Methyl Parathion	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83462

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the four samples exceeded the the water quality criteria/objective.

Data Reference:

Data for Various Pollutants in Ventura County, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The Department of Fish and Game instantaneous criteria for Methyl parathion; parathion, methyl is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Spatial Representation:

The four samples were collected at Calleguas Creek at University Drive, North Fork Arroyo Conejo (tributary to Conejo Creek)at sampling location Thousand Oaks-1.

Temporal Representation:

Two samples were collected in 2009 (10/14/2009 & 12/8/2009) and two samples were collected in 2010 (2/6/2010 & 3/18/2010).

Environmental Conditions:

There was no special environmental condition reported.

QAPP Information:

Samples were collected and analyzed in accordance to Ventrua County Agricultural Irrigated Land Group (VCAILG) Quality Assurance Project Plan (QAPP) dated Augus 3, 2006.

QAPP Information Reference(s):


DECISION ID	94533	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Metribuzin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 4 samples exceeded the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA 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. 0 of 4 samples exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94533, Metribuzin	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83463

Pollutant:

Metribuzin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 4 samples exceeded the water quality evaluation guideline criteria.

Data Reference:

Data for Various Pollutants in Ventura County, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan states "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Freshwater Aquatic Life Protection Recommended Criteria Maximum(Instantaneous) is 100 ug/L.

Guideline Reference:

Spatial Representation:

Four samples were collected at Calleguas Creek at University Drive, North Fork Arroyo Conejo (tributary to Conejo Creek)at sampling location Thousand Oaks-1.

Temporal Representation:

Two samples were collected in 2009 (12/14/2009 & 12/8/2009) and two samples in 2010 (2/22/2010 & 3/18/2010).

Environmental Conditions:

There was no special environmental condition reported.

QAPP Information:

Samples were collected and analyzed in accordance to Ventrua County Agricultural Irrigated Land Group (VCAILG) Quality Assurance Project Plan (QAPP) dated Augus 3, 2006.

QAPP Information Reference(s):


DECISION ID	100405	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Mirex
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 21 samples exceeded the CRITERIA. 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 CWA 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. 0 of 21 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 100405, Mirex	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83467

Pollutant:

Mirex

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 21 samples exceeded the water quality evaluation guideline criteria.

Data Reference:

Data for Various Pollutants in Ventura County, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan states "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Freshwater Aquatic Life Protection Recommended Criteria Maximum (Instantaneous) is 0.001 ug/L. (The US EPA 1976 and also appears in current list).

Guideline Reference:

Spatial Representation:

Twenty-one samples were collected at Calleguas Creek at University Drive, North Fork Arroyo Conejo (tributary to Conejo Creek)at sampling location Thousand Oaks-1.

Temporal Representation:

Water samples were collected in 2006 (one sample), in 2007 (6 samples), in 2008 (6 samples), in 2009 (6 samples) and in 2010 (two samples).

Environmental Conditions:

There was no special environmental condition reported.

QAPP Information:

Samples were collected and analyzed in accordance to Ventrua County Agricultural Irrigated Land Group (VCAILG) Quality Assurance Project Plan (QAPP) dated Augus 3, 2006.

QAPP Information Reference(s):


DECISION ID	94241	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Nickel
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 2 lines of evidence are available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. 0 of 36 samples exceeded the CRITERIA. 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 CWA 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. 0 of 1 and 0 of 36 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94241, Nickel	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83468

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 94241, Nickel	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83471

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 36 samples exceeded the evaluation guideline.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Temporal Representation:

Environmental Conditions:

Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West).

QAPP Information:

QAPP Information Reference(s):


DECISION ID	94473	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA 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. 0 of 1 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94473, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83472

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Table 3-8 of The Water Quality Control Plan for the Los Angeles Region specifies the Nitrate/Nitrite as N objective for the Calleguas Creek Reach 12 (was Conejo Creek/Arroyo Conejo North Fork on 1998 303d list) within the Calleguas-Conejo Creek watershed's Above Portrero Road reach boundary as 10 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94242	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

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:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 2 lines of evidence are available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. 0 of 132 samples exceeded the CRITERIA. 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 CWA 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. 0 of 1 and 0 of 132 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94242, Nitrogen, ammonia (Total Ammonia)	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83475

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

132

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Zero of the 132 samples exceeded the objective for ammonia.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected in two locations: R-1 and R-2.

Temporal Representation:

Samples were collected monthly from January 2005 through June 2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 94242, Nitrogen, ammonia (Total Ammonia)	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

94376

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Surface water shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94667	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Oxygen, Dissolved
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 572 samples exceeded the OBJECTIVE. 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 CWA 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. 0 of 572 samples exceeded the OBJECTIVE 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94667, Oxygen, Dissolved	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83477

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Numeric data generated from 4 minimums of Dissolved Oxygen concentrations had no exceedences.

Data Reference:

Data for Metals, Nuisance, Nutrients, Other Inorganics, and Salinity in Various Region 4 Water Bodies, 2006-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Dissolved Oxygen Water Quality Objective of all surface waters designated as Warm Fresh Water Aquatic Habitat shall not be depressed below 5 mg/l.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the R1_CONCRK station.

Temporal Representation:

Samples were collected annually from 2006 to 2008

Environmental Conditions:

QAPP Information:

NPDES quality assurance.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 94667, Oxygen, Dissolved	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83478

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

567

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Numeric data generated from 567 minimums of Dissolved Oxygen concentrations had no exceedences.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Dissolved Oxygen Water Quality Objective of all surface waters designated as Warm Fresh Water Aquatic Habitat shall not be depressed below 5 mg/l.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the R1 and R2 stations.

Temporal Representation:

Samples were collected once a week from January 2005 to June 2010.

Environmental Conditions:

QAPP Information:

NPDES quality assurance.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 94667, Oxygen, Dissolved	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83476

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region (page 3-11) states that: "The dissolved oxygen content of all surface waters designated as WARM shall not be depressed below 5 mg/L as a result of waste discharges."

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94244	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Pentachlorophenol (PCP)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 18 samples exceeded the CRITERIA. 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 CWA 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. 0 of 18 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94244, Pentachlorophenol (PCP)	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83514

Pollutant:

Pentachlorophenol (PCP)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 18 samples exceeded the water quality criteria/objective.

Data Reference:

Data for Various Pollutants in Ventura County, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA Nationally Recommended Criteria Continuous Concentration (4-day Average) for Aquatic Life is 15 ug/L. Which is calculated based on a pH of 7.8 using equation CCC=exp(1.005(pH) - 5.134).

Guideline Reference:

Spatial Representation:

Eighteen samples were collected at Calleguas Creek at University Drive.

Temporal Representation:

Water samples were collected in 2006 (one sample), in 2007 (7 samples), in 2008 (6 samples), in 2009 (4 samples.

Environmental Conditions:

There was no special environmental condition reported.

QAPP Information:

Samples were collected and analyzed in accordance to Ventrua County Agricultural Irrigated Land Group (VCAILG) Quality Assurance Project Plan (QAPP) dated Augus 3, 2006.

QAPP Information Reference(s):


DECISION ID	94668	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Permethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 0 sample exceeded the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA 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. 0 of 0 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94668, Permethrin	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83520

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed SWAMP data for Calleguas Creek Reach 12 (was Conejo Creek/Arroyo Conejo North Fork on 1998 303d list) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Permethrin, Total. One sample was not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Permethrin; Permethrin, total does not exceed 0.0002 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94184	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Selenium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 2 lines of evidence are available in the administrative record to assess this pollutant. 1 of 1 sample exceeded the CRITERIA. 0 of 36 samples exceeded the CRITERIA. 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 CWA 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. 1 of 1 and 0 of 36 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94184, Selenium	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83534

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 36 samples exceeded the evaluation guideline.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxics Rule Criteria Continuous Concentrations are intended protect aquatic organisms from chronic exposures (expressed as 4-day average concentration) in freshwater. The evaluation guideline for Selenium is 5.0 ug/L to protect warm freshwater habitat.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Temporal Representation:

Environmental Conditions:

Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West).

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 94184, Selenium	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83533

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.005 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94474	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Silver
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA 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. 0 of 1 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94474, Silver	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83535

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94666	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Temperature, water
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 1 line of evidence is available in the administrative record to assess this pollutant. 3 of 568 samples exceeded the OBJECTIVE. Based on the readily available data and information, the weight of evidence indicates that there is not sufficient justification in favor of placing this water segment-pollutant combination on the CWA 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. 3 of 568 samples exceeded the OBJECTIVE 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94666, Temperature, water	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83538

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

567

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Weekly temperature samples were taken between 2005 and 2010. There were 3 out of 567 exceedances of the evaluation guideline. It should also be noted that temperatures downstream of the discharge were much higher than the upstream measurements. In some cases, there was almost a 30 degree F difference.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

For waters designated as WARM, water temperature shall not be altered more than 5 degrees F above the natural temperature. At no time shall these WARM designated waters be raised above 80 degrees F as a result of waste discharges.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

At no time shall these WARM designated waters be raised above 80 degrees F as a result of waste discharges.

Guideline Reference:

Fish introductions in CA: History and impact on native fishes. Davis, CA: University of CA, Davis

Spatial Representation:

Samples collected at two different sample locations (R-1 and R-2); R-1: North Fork Arroyo conejo, 50 feet upstream of discharge No. 005, and R-2: North Fork Arroyo Conejo, 200 feet downstream of discharge No. 005.

Temporal Representation:

Samples collected weekly from January of 2005 through June of 2010.

Environmental Conditions:

QAPP Information:

Data collected for NPDES PERMIT NO. CA0056294 CITY OF THOUSAND OAKS HILL CANYON WASTEWATER TREATMENT PLANT.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 94666, Temperature, water	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83537

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

For waters designated WARM, water temperature shall not be altered by more than 5 deg. F above the natural temperature. At no time shall these WARM-designated waters be raised above 80 deg. F as a result of waste discharges.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94475	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Toxicity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA 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. 0 of 1 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94475, Toxicity	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

82627

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

One sample was collected to evaluate water toxicity. None of the samples exhibited significant toxicity. The toxicity test included survival and reproduction of Ceriodaphnia dubia. One sample can have multiple toxicity test results but will be counted only once. One sample is defined as being collected on the same day at the same location with the same lab sample id (if provided).

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life. Region 4 Basin Plan.

Objective/Criterion Reference:

Evaluation Guideline:

Toxicity is defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing. For SWAMP data exceedances are counted with the significant effect code SL. SL is defined as the result being significant compared to the negative control based on a statistical test, less than stated the alpha level, AND less than the evaluation threshold.

Guideline Reference:

Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013

Spatial Representation:

The sample was collected at station 408BA0036.

Temporal Representation:

The sample was collected in May 2008.

Environmental Conditions:

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.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	94183	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Zinc
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 2 lines of evidence are available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. 0 of 36 samples exceeded the CRITERIA. 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 CWA 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. 0 of 1 and 0 of 36 samples exceeded the CRITERIA 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94183, Zinc	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83545

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 94183, Zinc	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83546

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 36 samples exceeded the evaluation guideline.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Temporal Representation:

Environmental Conditions:

Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West).

QAPP Information:

QAPP Information Reference(s):


DECISION ID	94586	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	pH
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. 5 lines of evidence are available in the administrative record to assess this pollutant. 0 of 570 samples exceeded the OBJECTIVE. 0 of 1 sample exceeded the OBJECTIVE. 0 of 1 sample exceeded the OBJECTIVE. 0 of 1 sample exceeded the OBJECTIVE. 0 of 1 sample exceeded the OBJECTIVE. 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 CWA 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. 0 of 570, 0 of 1, 0 of 1, 0 of 1 and 0 of 1 sample exceeded the OBJECTIVE 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 94586, pH	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83531

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

567

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Numeric data generated from 567 minimums and maximums had no exceedences.

Data Reference:

Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH of all inland surface waters shall not be depressed below 6.5 or raised above 8.5 as a result of waste discharges.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the R1 and R2 stations.

Temporal Representation:

Samples were collected once a week from January 2005 to June 2010.

Environmental Conditions:

QAPP Information:

NPDES quality assurance.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 94586, pH	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83529

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Numeric data generated from 3 minimums and maximums of pH had no exceedences.

Data Reference:

Data for Metals, Nuisance, Nutrients, Other Inorganics, and Salinity in Various Region 4 Water Bodies, 2006-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH of all inland surface waters shall not be depressed below 6.5 or raised above 8.5 as a result of waste discharges.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the R1_CONCRK station.

Temporal Representation:

Samples were collected once in 2007 and twice in 2008.

Environmental Conditions:

QAPP Information:

NPDES quality assurance.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 94586, pH	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83522

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Los Angeles Basin: the pH for insland surface waters, bays, or estuaries shall not be depressed below 6.5 or raised above 8.5 as a result of waste discharges.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 94586, pH	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83521

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Los Angeles Basin: the pH for insland surface waters, bays, or estuaries shall not be depressed below 6.5 or raised above 8.5 as a result of waste discharges.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 94586, pH	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83528

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Los Angeles Basin: the pH for insland surface waters, bays, or estuaries shall not be depressed below 6.5 or raised above 8.5 as a result of waste discharges.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/5/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 94586, pH	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

83530

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

0 of 1 samples exceed the water quality objective.

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Los Angeles Region (LARWQCB 1994): In inland surface waters the pH shall not be depressed below 6.5 nor raised above 8.5. Ambient pH levels shall not be changed more than 0.5 units from natural conditions as a result of waste discharge.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at 408BA0036 (North Fork Arroyo Conejo Random Site 36).

Temporal Representation:

Samples collected on 5/5/2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	68934	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	Dieldrin
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)(2016)
Revision Status	Original
Sources:	A Source Unknown
TMDL Name:	Calleguas Creek Historic Pesticides (5)
TMDL Project Code:	358
Date TMDL Approved by USEPA:	03/14/2006
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Dieldrin has not been specifically listed on the 303(d) list for this water body. The USEPA final decision for the 2006 303(d) list added this listing to the being addressed by USEPA approved TMDL portion of the 303(d) List because the Calleguas Creek OC Pesticides & PCBs TMDL was approved by USEPA on 03/14/2006.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 68934, Dieldrin	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

2191

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Unspecified--This LOE is a placeholder to support a listing decision made by USEPA for 2006.

Data Reference:

SWAMP Data:

Non-SWAMP

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	70227	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

Pollutant:	PCBs (Polychlorinated biphenyls)
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)(2016)
Revision Status	Original
Sources:	A Source Unknown
TMDL Name:	Calleguas Creek PCBs (7)
TMDL Project Code:	360
Date TMDL Approved by USEPA:	03/14/2006
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Region 4 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle. PCBs have not been listed on the 303(d) list for this water body. The USEPA final decision for the 2006 303(d) list added this listing to the being addressed by USEPA approved TMDL portion of the 303(d) List because the Calleguas Creek OC Pesticides & PCBs TMDL was approved by USEPA on 03/14/2006.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 70227, PCBs (Polychlorinated biphenyls)	Region 4
Calleguas Creek Reach 12 (North Fork Arroyo Conejo)

LOE ID:

2192

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Unspecified--This LOE is a placeholder to support a listing decision made by USEPA for 2006.

Data Reference: