Final California 2018 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name:	Walters Creek
Water Body ID:	CAR3102201120021002231800
Water Body Type:	River & Stream


DECISION ID	83536	Region 3
Walters Creek

Pollutant:	Escherichia coli (E. coli)
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 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. The sample size for the evaluation guideline for water contact recreation for Escherichia coli (E. coli) 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 supported and a minimum of five exceedances is needed to determine if beneficial uses are not supported using Table 3.2. Therefore, the use support rating is set to 'insufficient information'. One line of evidence is available in the administrative record to assess this pollutant. Two of 9 samples exceed the evaluation guideline (USEPA Ambient Water Quality Criteria for Bacteria -1986) set to protect for water contact recreation (i.e. swimming, wading etc.). 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. Two of 9 samples exceed the evaluation guideline set to protect for water contact recreation (i.e. swimming, wading etc.) 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. 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 83536, Escherichia coli (E. coli)	Region 3
Walters Creek

LOE ID:

47818

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Region 3 - Central Coast Region staff assessed R3 public submissions data for Walters Creek to determine beneficial use support and results are as follows: 2 of 9 samples exceed the criterion for Escherichia coli.

Data Reference:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

USEPA Ambient Water Quality Criteria for Bacteria -1986.

Objective/Criterion Reference:

Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Evaluation Guideline:

Single sample maximum allowable density for E. coli in freshwater is 235 MPN/100mL (as stated in Table 4, page 15 of the USEPA Ambient Water Quality Criteria for Bacteria -1986).

Guideline Reference:

Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 8/6/2002 2:06:00 PM-1/5/2006 8:15:00 AM.

Environmental Conditions:

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

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2


DECISION ID	87232	Region 3
Walters Creek

Pollutant:	Nitrate
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. Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the 6 nitrate samples exceed the water quality objectives for municipal and domestic supply use (i.e. drinking water) and agricultural uses. Although two of the 6 samples exceed the Central Coast Region¿s evaluation guideline for maximum nitrate concentration (R3 NNE Technical Report, 2010) and the protection of aquatic life uses from bio-stimulatory or eutrophic effects (i.e. enhanced algal and aquatic plant growth and unhealthy dissolved oxygen fluctuations), there is no supporting evidence indicating high risk for, or occurrence of, eutrophication (such as low dissolved oxygen or elevated chlorophyll a concentrations). 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. 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. Zero of the 6 nitrate samples exceed the water quality objectives for municipal and domestic supply use (i.e. drinking water) and agricultural uses. Although two of the 6 samples exceed the Central Coast Region¿s evaluation guideline for maximum nitrate concentration but there is not supporting evidence of eutrophic conditions. These do 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 87232, Nitrate	Region 3
Walters Creek

LOE ID:

47819

Pollutant:

Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Region 3 - Central Coast Region staff assessed R3 public submissions data for Walters Creek to determine beneficial use support and results are as follows: 2 of 6 samples exceed the criterion for Nitrate as N.

Data Reference:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Technical approach to develop nutrient numeric endpoints for California, Tetra Tech, June 2006. The Central Coast Region numeric target for maximum nitrate concentration is based on the Tetra Tech NNE (Nutrient Numeric Endpoint) Model and CCAMP data for 193 sites, monitored monthly for at least 1 year between January 1998 and December 2006. The model numeric target for aquatic life habitats in the Central Coast Region is 1.0 mg/L Nitrate as N.

Guideline Reference:

Technical Approach to Develop Nutrient Numeric Endpoints for California. U.S. EPA Region IX. State Water Resources Control Board. 68-C-02-108-To-111

Guideline Reference:

Central Coast RegionTechnical Paper: Interpreting Narrative Objectives for Biostimulatory Substances for California Central Coast Waters. This method uses the Technical Approach for Developing California Nutrient Numeric Endpoints.

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

Nitrate data was collected using a screening level test kit. Quality control is consistent with the QAPP.

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2

Line of Evidence (LOE) for Decision ID 87232, Nitrate	Region 3
Walters Creek

LOE ID:

47820

Pollutant:

Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Region 3 - Central Coast Region staff assessed R3 public submissions data for Walters Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceed the criterion for Nitrate as N.

Data Reference:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nitrate (NO3 as N) incorporated by reference in the Basin Plan is 10.0 mg/L (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

Nitrate data was collected using a screening level test kit. Quality control is consistent with the QAPP.

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2

Line of Evidence (LOE) for Decision ID 87232, Nitrate	Region 3
Walters Creek

LOE ID:

47821

Pollutant:

Nitrate

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:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Technical Approach to Develop Nutrient Numeric Endpoints for California. U.S. EPA Region IX. State Water Resources Control Board. 68-C-02-108-To-111

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

Nitrate data was collected using a screening level test kit. Quality control is consistent with the QAPP.

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2


DECISION ID	85520	Region 3
Walters Creek

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. Four lines of evidence are available in the administrative record to assess this pollutant. One of the 5 samples exceeded the water quality objectives for dissolved oxygen in both Cold and Warm Freshwater Habitats. 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 supported and a minimum of five exceedances is needed to determine if beneficial uses are not supported using table 3.2. Therefore, the use support rating is set to 'insufficient information'. Additionally, the Basin Plan general water quality objective for oxygen saturation states that the median value shall not fall below 85% saturation. However, the oxygen saturation objective is only applied ¿for waters not mentioned by a specific beneficial use¿¿ and this water body is designated for both Cold and Warm Freshwater Habitats. Therefore, the use support rating for oxygen saturation is set at Insufficient Information. 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. One of the 5 samples exceeded the water quality objectives 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. 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 85520, Oxygen, Dissolved	Region 3
Walters Creek

LOE ID:

47823

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:

Region 3 - Central Coast Region staff assessed R3 public submissions data for Walters Creek to determine beneficial use support and results are as follows: 1 of 5 samples exceed the criterion for Oxygen, Dissolved.

Data Reference:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

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

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2

Line of Evidence (LOE) for Decision ID 85520, Oxygen, Dissolved	Region 3
Walters Creek

LOE ID:

47822

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

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

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2

Line of Evidence (LOE) for Decision ID 85520, Oxygen, Dissolved	Region 3
Walters Creek

LOE ID:

47824

Pollutant:

Dissolved oxygen saturation

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Region 3 - Central Coast Region staff assessed R3 public submissions data for Walters Creek to determine beneficial use support and results are as follows: 4 of 5 samples exceed the criterion for Oxygen, Saturation.

Data Reference:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Median values should not fall below 85% saturation as a result of controllable water quality conditions (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

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

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2

Line of Evidence (LOE) for Decision ID 85520, Oxygen, Dissolved	Region 3
Walters Creek

LOE ID:

47835

Pollutant:

Dissolved oxygen saturation

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:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Median values should not fall below 85% saturation as a result of controllable water quality conditions (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

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

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2


DECISION ID	86614	Region 3
Walters Creek

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. One line of evidence is available in the administrative record to assess this pollutant. Zero of the five samples exceed the evaluation guideline (Moyle, 1976) used to interpret the water quality objective for water temperature. 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 supported and a minimum of five exceedances is needed to determine if beneficial uses are not supported using table 3.2. Therefore, the use support rating is set to 'insufficient information'. 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. Zero of the five samples exceed the evaluation guideline 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. 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 86614, Temperature, water	Region 3
Walters Creek

LOE ID:

47853

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Region 3 - Central Coast Region staff assessed R3 public submissions data for Walters Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceed the criterion for Water Temperature.

Data Reference:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The optimum range for growth and completion of most life stages of rainbow trout is 13-21 degrees Celsius (Moyle 1976).

Guideline Reference:

The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

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

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2


DECISION ID	86201	Region 3
Walters Creek

Pollutant:	Turbidity
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. Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the 6 samples exceed the evaluation guideline for Cold Freshwater Habitat (Sigler et al. 1984) and 0 of the 6 samples exceed the Warm Freshwater Habitat evaluation guideline (Shoup, D.E. and Wahl D.H., 2009), both used to interpret the water quality objective for turbidity. 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 supported and a minimum of five exceedances is needed to determine if beneficial uses are not supported using table 3.2. Therefore, the use support rating is set to 'insufficient information'. 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. Zero of the 6 samples exceed the evaluation guideline for both Cold and Warm Freshwater Habitats 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. 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 86201, Turbidity	Region 3
Walters Creek

LOE ID:

47852

Pollutant:

Turbidity

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:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Turbidities of 40 NTU or greater can cause a reduction in piscivorous fish (largemouth bass) growth due to interference with their ability to find food (Shoup, D.E. and Wahl D.H., 2009).

Guideline Reference:

Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

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

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2

Line of Evidence (LOE) for Decision ID 86201, Turbidity	Region 3
Walters Creek

LOE ID:

47841

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. (Basin Plan)

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Turbidities of 25 NTU or greater can cause a reduction in juvenile salmonid growth due to interference with their ability to find food (Sigler et al. 1984).

Guideline Reference:

Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

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

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2


DECISION ID	86202	Region 3
Walters Creek

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. Five lines of evidence are available in the administrative record to assess this pollutant. Four beneficial uses are assessed. Two of the 6 samples exceed the water quality objectives for both Cold and Warm Freshwater Habitats. Zero of the 6 samples exceed the water quality objectives for Drinking Water and Recreation. These sample sizes are 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 supported and a minimum of five exceedances is needed to determine if beneficial uses are not supported using table 3.2. Therefore, the use support rating is set to 'insufficient information'. 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. Two of the 6 samples exceed the water quality objectives for both Cold and Warm Freshwater Habitats. Zero of the 6 samples exceed the water quality objectives for Drinking Water and Recreation and none of these exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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 86202, pH	Region 3
Walters Creek

LOE ID:

47837

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Region 3 - Central Coast Region staff assessed R3 public submissions data for Walters Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceed the criterion for pH.

Data Reference:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH value shall not be depressed below 6.5 or raised above 8.3 (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

pH was measured using test strips. In recent communication with the program QA officer concern has been raised about underestimation of the result with test strips.

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2

Line of Evidence (LOE) for Decision ID 86202, pH	Region 3
Walters Creek

LOE ID:

47839

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:

Region 3 - Central Coast Region staff assessed R3 public submissions data for Walters Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceed the criterion for pH.

Data Reference:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH value shall neither be depressed below 6.5 nor raised above 8.3 (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

pH was measured using test strips. In recent communication with the program QA officer concern has been raised about underestimation of the result with test strips.

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2

Line of Evidence (LOE) for Decision ID 86202, pH	Region 3
Walters Creek

LOE ID:

47840

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:

Region 3 - Central Coast Region staff assessed R3 public submissions data for Walters Creek to determine beneficial use support and results are as follows: 2 of 6 samples exceed the criterion for pH.

Data Reference:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH value shall not be depressed below 7.0 or raised above 8.5 (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

pH was measured using test strips. In recent communication with the program QA officer concern has been raised about underestimation of the result with test strips.

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2

Line of Evidence (LOE) for Decision ID 86202, pH	Region 3
Walters Creek

LOE ID:

47838

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:

Region 3 - Central Coast Region staff assessed R3 public submissions data for Walters Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceed the criterion for pH.

Data Reference:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH value shall neither be depressed below 6.5 nor raised above 8.3 (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

pH was measured using test strips. In recent communication with the program QA officer concern has been raised about underestimation of the result with test strips.

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2

Line of Evidence (LOE) for Decision ID 86202, pH	Region 3
Walters Creek

LOE ID:

47836

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Region 3 - Central Coast Region staff assessed R3 public submissions data for Walters Creek to determine beneficial use support and results are as follows: 2 of 6 samples exceed the criterion for pH.

Data Reference:

Data from Morro Bay National Estuary Program's Volunteer Monitoring Program, May 2002-Apr. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH value shall not be depressed below 7.0 or raised above 8.5 (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walters Creek was collected at 1 monitoring site [ 310WAL-Walters Creek]

Temporal Representation:

Data was collected over the time period 12/15/2002 11:15:00 AM-1/29/2008 2:38:00 PM.

Environmental Conditions:

pH was measured using test strips. In recent communication with the program QA officer concern has been raised about underestimation of the result with test strips.

QAPP Information:

All data was collected in compliance with an EPA approved QAPP

QAPP Information Reference(s):

Quality Assurance Project Plan for Morro Bay National Estuary Program¿s Volunteer Monitoring Program. Jan. 12, 2010, Version 5, Draft 2


DECISION ID	69640	Region 3
Walters Creek

Pollutant:	Fecal Coliform
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2027
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for listing under section 2.2 of the Listing Policy. Under this section of the Policy, a minimum of one line of evidence is needed to assess listing status. Based on the readily available information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination in the Water Quality Limited Segments Being Addressed portion of the section 303(d) list. USEPA in its final decision for the 2006 303(d) list, has determined that a TMDL has not been approved by USEPA for this pollutant water body combination. Therefore, this water body pollutant combination is being placed back on the 303(d) list (TMDL required list) pending completion and USEPA approval of a TMDL.

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 cycle. 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 69640, Fecal Coliform	Region 3
Walters Creek

LOE ID:

1899

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

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:

Placeholder reference 2006 303(d)

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):