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

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name:	Los Osos Creek (Los Osos to Los Osos Creek Estuary)
Water Body ID:	CAR3102300020150205055908
Water Body Type:	River & Stream


DECISION ID	85084	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

Pollutant:	Oxygen, Dissolved
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 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 removal from the CWA section 303(d) List under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. One of the six samples exceeded the water quality objective for dissolved oxygen in 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'. The Basin Plan general water quality objective for oxygen saturation states that the median value shall not fall below 85% saturation. Furthermore, 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 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. One of the six samples exceeded the water quality objective and this is not enough data to determine if the beneficial use is supported or not. Therefore there is not enough evidence to remove this water segment from the List. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met. Note: This decision was formerly associated with Los Osos Creek but in the 2014 assessment cycle was transferred to the newly mapped Los Osos Creek (Los Osos to Los Osos Creek Estuary), where the monitoring stations associated with the LOEs in this decision are located. The 'Listing Year' associated with every LOE is 2014, regardless of the year the LOE was created. This is because the old LOEs (pre 2014) were moved to this newly mapped water segment in 2014 and this process changed the date associated with the LOE in the assessment data base.

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:	Note: This decision was formerly associated with Los Osos Creek but in the 2014 assessment cycle was transferred to the newly mapped Los Osos Creek (Los Osos to Los Osos Creek Estuary), where the monitoring stations associated with the LOEs in this decision are located. The 'Listing Year' associated with every LOE is 2014, regardless of the year the LOE was created. This is because the old LOEs (pre 2014) were moved to this newly mapped water segment in 2014 and this process changed the date associated with the LOE in the assessment data base.

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 85084, Oxygen, Dissolved	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80776

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:

Region 3 - Central Coast Region staff assessed R3 public submissions data for Los Osos Creek (Los Osos to Morro Bay) to determine beneficial use support and results are as follows: 1 of 6 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 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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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 85084, Oxygen, Dissolved	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80780

Pollutant:

Low Dissolved Oxygen

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold 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:

Placeholder reference pre-2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Unspecified

Objective/Criterion Reference:

Placeholder reference pre-2006 303(d)

Evaluation Guideline:

Unspecified

Guideline Reference:

Placeholder reference pre-2006 303(d)

Spatial Representation:

Unspecified

Temporal Representation:

Unspecified

Environmental Conditions:

Unspecified

QAPP Information:

Unspecified

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 85084, Oxygen, Dissolved	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80782

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:

Region 3 - Central Coast Region staff assessed R3 public submissions data for Los Osos Creek (Los Osos to Morro Bay) to determine beneficial use support and results are as follows: 1 of 7 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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 8/28/2002 3:30:00 PM-3/5/2010 12:25:00 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 85084, Oxygen, Dissolved	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80790

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 Los Osos Creek (Los Osos to Morro Bay) to determine beneficial use support and results are as follows: 1 of 7 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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 8/28/2002 3:30:00 PM-3/5/2010 12:25:00 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 85084, Oxygen, Dissolved	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80775

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:

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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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	84770	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

Pollutant:	Fecal Coliform
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Domestic Pet Waste \| Grazing-Related Sources \| Natural Sources \| Onsite Wastewater Systems (Septic Tanks) \| Transient encampments \| Urban Runoff/Storm Sewers
TMDL Name:	Morro Bay Pathogens
TMDL Project Code:	22
Date TMDL Approved by USEPA:	01/20/2004
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	No new data were assessed. This pollutant is being considered for delisting under section 2.2 of the Listing Policy. Under this section of the Policy, a minimum of one line of evidence is needed to assess listing status. The Morro Bay Pathogens TMDL was approved by RWQCB on May 16, 2003 and subsequently approved by USEPA on January 20, 2004. LOE # 1907 is a placeholder for this listing which was made prior to 2006 when the assessment data base was initiated. The original listing was based on 10 years of data from the National monitoring Program in the Morro Bay Watershed. Two additional LOE summarize a single sample and the single sample does not exceed the water quality objectives for Water Contact Recreation or Non-Contact Recreation. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification in favor of delisting this water segment-pollutant combination from the Water Quality Limited Segments Being Addressed portion of the section 303(d) list.

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 84770, Fecal Coliform	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80807

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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):


DECISION ID	87228	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

Pollutant:	Nitrate
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:	Agriculture \| Grazing-Related Sources
TMDL Name:	Los Osos Creek Nutrients
TMDL Project Code:	597
Date TMDL Approved by USEPA:	03/01/2005
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. In the 2014 assessment cycle, the pollutant name has been changed from 'Nutrients' to 'Nitrate' which is the pollutant addressed in the TMDL. Five lines of evidence are available in the administrative record to assess this pollutant. The original listing decision was made by USEPA and the data supporting that decision are not available in this assessment database. More recent data shows that zero of six samples exceed the water quality objectives for Municipal and Domestic Supply and Agriculture and zero of six samples exceed the evaluation guidelines for protection of aquatic life from eutrophic effects. 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 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 [NUMBER] of the Policy. 2. The data used satisfies the data quantity requirements of section NUMBER of the Policy. 3. The original listing decision was made by USEPA and the data supporting that decision are not available in this assessment database. More recent data shows that zero of six samples exceed the water quality objectives for Municipal and Domestic Supply and Agriculture and zero of six samples exceed the evaluation guidelines for protection of aquatic life from eutrophic effects. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. 4. The Los Osos Creek, Warden Creek, and Warden Lake Wetland TMDL for Nutrients has been approved by USEPA. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Note: This decision was formerly associated with Los Osos Creek but in the 2014 assessment cycle was transferred to the newly mapped Los Osos Creek (Los Osos to Los Osos Creek Estuary), where the monitoring stations associated with the LOEs in this decision are located. The 'Listing Year' associated with every LOE is 2014, regardless of the year the LOE was created. This is because the old LOEs (pre 2014) were moved to this newly mapped water segment in 2014 and this process changed the date associated with the LOE in the assessment data base.

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. 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.

State Board Review of Regional Board Conclusion and Recommendation:	Note: This decision was formerly associated with Los Osos Creek but in the 2014 assessment cycle was transferred to the newly mapped Los Osos Creek (Los Osos to Los Osos Creek Estuary), where the monitoring stations associated with the LOEs in this decision are located. The 'Listing Year' associated with every LOE is 2014, regardless of the year the LOE was created. This is because the old LOEs (pre 2014) were moved to this newly mapped water segment in 2014 and this process changed the date associated with the LOE in the assessment data base.

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 87228, Nitrate	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80766

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:

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):

Line of Evidence (LOE) for Decision ID 87228, Nitrate	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80754

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:

Region 3 - Central Coast Region staff assessed R3 public submissions data for Los Osos Creek (Los Osos to Morro Bay) 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:

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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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 87228, Nitrate	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80753

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 Los Osos Creek (Los Osos to Morro Bay) 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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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 87228, Nitrate	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80755

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 Los Osos Creek (Los Osos to Morro Bay) 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:

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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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 87228, Nitrate	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80756

Pollutant:

Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Agricultural 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 Los Osos Creek (Los Osos to Morro Bay) 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:

Waters shall not contain concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when nitrate exceeds 30 mg/L NO3 as N in irrigation supply water.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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	84721	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

Pollutant:	Sedimentation/Siltation
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:	Erosion/Siltation
TMDL Name:	Morro Bay Sediment
TMDL Project Code:	242
Date TMDL Approved by USEPA:	01/20/2004
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for delisting under section 2.2 of the Listing Policy. Under this section of the Policy, a minimum of one line of evidence is needed to assess listing status. The Morro Bay Sediment TMDL was approved by RWQCB on May 16, 2003 and subsequently approved by USEPA on January 20, 2004. No new data is available to evaluate this listing. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification in favor removing this water segment-pollutant combination from the Water Quality Limited Segments Being Addressed portion of the section 303(d) list.

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 84721, Sedimentation/Siltation	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80805

Pollutant:

Sedimentation/Siltation

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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:

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):


DECISION ID	84955	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

Pollutant:	Specific Conductivity
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:	Note: This decision was formerly associated with Los Osos Creek but in the 2014 assessment cycle was transferred to the newly mapped Los Osos Creek (Los Osos to Los Osos Creek Estuary), where the monitoring stations associated with the LOEs in this decision are located. The 'Listing Year' associated with every LOE is 2014, regardless of the year the LOE was created. This is because the old LOEs (pre 2014) were moved to this newly mapped water segment in 2014 and this process changed the date associated with the LOE in the assessment data base. 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. Note that the pollutant name for the older LOEs and decisions is electrical conductivity. This was an error and the pollutant name should have always been specific conductivity. For this reason, the pollutant name was changed for this decision and sample and exceedance counts are summed for LOEs with both pollutant names in this assessment for specific conductivity. One line of evidence is available in the administrative record to assess this pollutant. Zero of the six samples exceed the water quality objective for agricultural uses. 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. Three of the nine samples exceed the water quality 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. 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 84955, Specific Conductivity	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80769

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Agricultural 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 Los Osos Creek (Los Osos to Morro Bay) to determine beneficial use support and results are as follows: 0 of 6 samples exceed the criterion for Conductivity(Us).

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 concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Waterboard Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when conductivity exceeds 3000 uS/cm in irrigation supply water.

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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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	100115	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

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:	Note: This decision was formerly associated with Los Osos Creek but in the 2014 assessment cycle was transferred to the newly mapped Los Osos Creek (Los Osos to Los Osos Creek Estuary), where the monitoring stations associated with the LOEs in this decision are located. The 'Listing Year' associated with every LOE is 2014, regardless of the year the LOE was created. This is because the old LOEs (pre 2014) were moved to this newly mapped water segment in 2014 and this process changed the date associated with the LOE in the assessment data base. 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 six 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 six 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 100115, Temperature, water	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80763

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 Los Osos Creek (Los Osos to Morro Bay) to determine beneficial use support and results are as follows: 0 of 6 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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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	84909	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

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:	Note: This decision was formerly associated with Los Osos Creek but in the 2014 assessment cycle was transferred to the newly mapped Los Osos Creek (Los Osos to Los Osos Creek Estuary), where the monitoring stations associated with the LOEs in this decision are located. The 'Listing Year' associated with every LOE is 2014, regardless of the year the LOE was created. This is because the old LOEs (pre 2014) were moved to this newly mapped water segment in 2014 and this process changed the date associated with the LOE in the assessment data base. 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 six samples exceed the evaluation guideline for Cold Freshwater Habitat (Sigler et al. 1984) but only 10 of the 101 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. One of the six samples exceed the evaluation guideline for Cold Freshwater Habitat but 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 84909, Turbidity	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80760

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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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 84909, Turbidity	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80764

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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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	87278	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

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. Six beneficial uses are assessed. Zero of the six samples exceed the water quality objectives for Agriculture, Cold and Warm Freshwater Habitats, Drinking Water and Recreation. 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 six samples exceed the water quality objectives for Agriculture, Cold and Warm Freshwater Habitats, Drinking Water and Recreation 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. Note: This decision was formerly associated with Los Osos Creek but in the 2014 assessment cycle was transferred to the newly mapped Los Osos Creek (Los Osos to Los Osos Creek Estuary), where the monitoring stations associated with the LOEs in this decision are located. The 'Listing Year' associated with every LOE is 2014, regardless of the year the LOE was created. This is because the old LOEs (pre 2014) were moved to this newly mapped water segment in 2014 and this process changed the date associated with the LOE in the assessment data base.

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:	Note: This decision was formerly associated with Los Osos Creek but in the 2014 assessment cycle was transferred to the newly mapped Los Osos Creek (Los Osos to Los Osos Creek Estuary), where the monitoring stations associated with the LOEs in this decision are located. The 'Listing Year' associated with every LOE is 2014, regardless of the year the LOE was created. This is because the old LOEs (pre 2014) were moved to this newly mapped water segment in 2014 and this process changed the date associated with the LOE in the assessment data base.

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 87278, pH	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80757

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Agricultural Supply

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 concentrations of chemical constituents in amounts which adversely affect the agricultural beneficial use. Interpretation of adverse effect shall be as derived from the University of California Agricultural Extension Service guidelines provided in Table 3-3 (Central Coast Region Basin Plan, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries). In Table 3-3 of the Basin Plan (page III-8), water quality guidelines state that severe problems may occur when pH is greater than 8.4 or less than 6.5 in irrigation supply water.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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 87278, pH	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80797

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:

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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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 87278, pH	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80799

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:

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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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 87278, pH	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80786

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:

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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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 87278, pH	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80789

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:

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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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 87278, pH	Region 3
Los Osos Creek (Los Osos to Los Osos Creek Estuary)

LOE ID:

80794

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:

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 Los Osos Creek (Los Osos to Morro Bay) was collected at 1 monitoring site [ 310LVR - Los Osos Creek]

Temporal Representation:

Data was collected over the time period 4/15/2003 2:00:00 PM-3/5/2010 12:25:00 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