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

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name: Morro Bay
Water Body ID: CAB3102201219980827141506
Water Body Type: Bay & Harbor
 
DECISION ID
83815
Region 3     
Morro Bay
 
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: 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. Two water quality objectives are assessed. A total of 240 of the 292 samples exceeded the water quality objective for dissolved oxygen in Cold Freshwater Habitats and 1701 of the 1721 samples exceeded the water quality objective for dissolved oxygen in Marine Habitats. 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 Marine 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. A total of 240 of the 292 samples exceeded the water quality objective for dissolved oxygen in Cold Freshwater Habitats and 1701 of the 1721 samples exceeded the water quality objective for dissolved oxygen in Marine Habitats. Each of these exceeds the allowable frequency listed in Table 4.2 of the Listing Policy.
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Staff 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 83815, Oxygen, Dissolved
Region 3     
Morro Bay
 
LOE ID: 80
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Adverse Biological Responses
Matrix: -N/A
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 283
Number of Exceedances: 231
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Regional Board staff is proposing that Morro Bay be listed as impaired for dissolved oxygen. The impairment is evidenced by depressed levels of dissolved oxygen measured during pre-dawn and 24-hour sampling periods. Two Hundred and thirty one data points (of a total of 283 data points) collected between 1997 and 2002 fell below the water quality objective of 7.0 mg/L (CCRWQCB, 2004o). Depressed oxygen levels were found at all sampling locations except for EEL. There were 231 out of 283 samples that exceeded the COLD dissolved oxygen water quality objective.
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: MAR = Marine Habitat
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline: COLD Dissolved Oxygen = 7.0 mg/L.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Morro Bay Estuary (Calwater watershed no. 31023012), San Luis Obispo County. Samples were collected at 8 locations throughout the bay: ATP, SPM, Lo2, PSP, EEL, Ch1, CSI, and SHI.
Temporal Representation: Single measurements were taken in the Morro Bay estuary using a hand-held meter. Measurements were taken during pre-dawn conditions from 4/17/1997 through 12/132002.
Environmental Conditions: Samples were primarily taken during pre-dawn conditions, when dissolved oxygen levels are expected to be lowest.
QAPP Information: Samples were taken according to the Morro Bay Volunteer Monitoring Program protocols for pre-dawn sampling in the Morro Bay National Estuary Programs Quality Assurance Program Plan.

The Morro Bay Volunteer Monitoring Program staff has monthly correspondence with volunteers regarding data review, meter operation, and safety. Volunteer monitors collect dissolved oxygen data according to the Morro Bay National Estuary Programs Quality Assurance Program Plan.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 83815, Oxygen, Dissolved
Region 3     
Morro Bay
 
LOE ID: 47758
 
Pollutant: Dissolved oxygen saturation
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 27
Number of Exceedances: 14
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Central Coast Water Board staff assessed public submissions data for Morro Bay to determine beneficial use support and results are as follows: The daily median oxygen saturation value was evaluated for 27 sample days and three monitoring sites In Morro Bay and the criterion was exceeded 14 times.
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 Morro Bay was collected at 3 monitoring sites [ EMB - Embarcadero dock Pilings, 310MIT - Mitchell Lane Dock and 310SPM - State Park Marina]
Temporal Representation: Data was collected over the time period July 27, 2005 - June 30, 2006
Environmental Conditions: Oxygen Saturation data were collected every 30 minutes for a minimum of 24 hours. Central Coast Water Board Staff counted the number of sample days and the daily median value for each sample day was compared to the water quality objective as defined in S
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 83815, Oxygen, Dissolved
Region 3     
Morro Bay
 
LOE ID: 47756
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 9
Number of Exceedances: 9
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Central Coast Water Board staff assessed public submissions data for Morro Bay to determine beneficial use support and results are as follows: The daily minimum dissolved oxygen concentration was evaluated for nine sample days and three monitoring sites in Morro Bay and the criterion was exceeded all 9 times.
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 Morro Bay was collected at 3 monitoring sites [ EMB - Embarcadero dock Pilings, 310MIT - Mitchell Lane Dock and 310SPM - State Park Marina]
Temporal Representation: Data was collected over the time period July 27, 2005 - June 30, 2006
Environmental Conditions: Dissolved oxygen data were collected every 30 minutes for a minimum of 24 hours. Central Coast Water Board Staff counted the number of sample days and the minimum value for each sample day was compared to the water quality objective as defined in Section
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 83815, Oxygen, Dissolved
Region 3     
Morro Bay
 
LOE ID: 55368
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Marine Habitat
 
Number of Samples: 1721
Number of Exceedances: 1701
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Numeric data generated from 1721 minimum of Dissolved Oxygen concentrations had 1701 exceedences.
Data Reference: Data for temperature and nutrients in Morro Bay and Chorro Creek
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from the BM1, BS1, CM1, and CM2 stations.
Temporal Representation: One sample was collected approximately once a day from January 2008 to December 2009.
Environmental Conditions:
QAPP Information: QA information contained in data submittal file and with the filename 'QA_LOE_water_sediment_tissue.pdf'.
QAPP Information Reference(s):
 
 
DECISION ID
68249
Region 3     
Morro Bay
 
Pollutant: Aluminum
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: No new data are assessed. This decision has not changed from the 2010 listing cycle.

This pollutant is being considered for placement on the section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5 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. Aluminum is one of five metals originally included in the 1996-303(d) metals listing. The listing was originally based on exceedances of Median International Standards (MIS) and Elevated Data Levels (EDL) guidelines for State Mussel Watch tissue data. The MIS and EDL guidelines do not meet the requirements of the Listing Policy. The CTR criteria for the dissolved fraction of selected metals are applicable for the protection of aquatic life but there is no CTR criterion for dissolved aluminum and there is no criterion or guideline for aluminum in tissue that meets the requirement of the Listing Policy.

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 by it self on the section 303(d) list.

This conclusion is based on the staff findings that:

1.The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2.The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. No exceedances of CTR criteria were recorded and no exceedances of aluminum in tissue were recorded because there is no criterion or guidelines for the dissolved fraction of aluminum or aluminum in tissue that meet the requirements 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 met.
 
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 Staff 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 68249, Aluminum
Region 3     
Morro Bay
 
LOE ID: 82
 
Pollutant: Aluminum
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: No exceedances were recorded for all 5 samples because there are no criterion or guidelines for the dissolved fraction of aluminum that meet the requirements of the Listing Policy (Keeling, 2003).

This is one of five metals originally included in the 1996-303(d) metals listing. The listing was originally based on exceedances of Median International Standards (MIS) and Elevated Data Levels (EDL) guidelines for State Mussel Watch tissue data. The MIS and EDL guidelines do not meet the requirements of the Listing Policy.
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain suspended material in concentrations that cause nuisance or adversely affect beneficial uses. Waters shall not contain settleable material in concentrations that result in deposition of material that causes nuisance or adversely affects beneficial uses.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline: The CTR criteria for the dissolved fraction of selected metals are applicable for the protection of aquatic life but there are no criteria or guidelines for the dissolved fraction of aluminum that meet the requirements of the Listing Policy.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: There were five sampling sites throughout Morro Bay. Locations represented the back, middle, and front of the Bay including inflows from Chorro and Los Osos Creeks. The stations were: Back Bay, Mouth Los Osos, Mouth Chorro, Middle Bay and Front Bay.
Temporal Representation: Water was sampled on March 8, 2001.
Environmental Conditions:
QAPP Information: Battelle Laboratory Quality Assurance Plan.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 68249, Aluminum
Region 3     
Morro Bay
 
LOE ID: 81
 
Pollutant: Aluminum
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Originally, one out of 12 analyzed samples exceeded the EDL 85 of 138.43 ppm. However, no exceedances are currently recorded because there are no criteria or guidelines for aluminum in tissue that meet the requirements of the Listing Policy (Keeling, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline: There are no tissue criteria for Aluminum.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: There were four stations sampled: 427.0, 428.5, 429.0 and 429.2.
Temporal Representation: Site 429.0 was sampled on 6/28/1982, 1/21/1983 and 5/3/1983. Site 429.2 was sampled on 1/26/1987, 3/14/1988, 12/19/1988, 2/2/1990 and 1/20/1993. Site 427.0 was sampled 5-30-1980 and 12-14-1980. Site 428.5 was sampled 5-30-1980 and 12-14-1980.
Environmental Conditions: This is one of five metals originally included in the 1996-303(d) metals listing. The listing was originally based on exceedances of Median International Standards (MIS) and Elevated Data Levels (EDL) guidelines for State Mussel Watch tissue data. The MIS and EDL guidelines do not meet the requirements of the Listing Policy (section 6.1.3.2).
QAPP Information: State Mussel Watch Program Quality Assurance Plan.
QAPP Information Reference(s):
 
 
DECISION ID
68059
Region 3     
Morro Bay
 
Pollutant: Barium
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 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.

One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality standards because there is no dissolved barium water quality objective, guideline or criteria for the protection of aquatic live in marine waters.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. A guideline for barium is not available that complies with the requirements of section 6.1.3 of the 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: 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 Staff 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 68059, Barium
Region 3     
Morro Bay
 
LOE ID: 93
 
Pollutant: Barium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: None of the five samples taken in Morro Bay, were in exceedance because there is no barium criterion or guideline for barium in marine waters (Keeling, S. 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain suspended material in concentrations that cause nuisance or adversely affect beneficial uses. Waters shall not contain settleable material in concentrations that result in deposition of material that causes nuisance or adversely affects beneficial uses.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Water was sampled from five (5) separate locations representing the back, middle and front of the Bay including inflows from the mouth Chorro and the mouth Los Osos creeks that feed into the Bay. The stations were: Back Bay, Mouth Los Osos, Mouth Chorro, Middle Bay and Front Bay.
Temporal Representation: Water was sampled on March 8, 2001.
Environmental Conditions:
QAPP Information: Battelle Laboratory Quality Assurance Plan.
QAPP Information Reference(s):
 
 
DECISION ID
99645
Region 3     
Morro Bay
 
Pollutant: Cadmium
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.5 of the Listing Policy. Under section 3.1, a single line of evidence is necessary to assess listing status. Under section 3.5, one line of evidence is necessary to assess listing status.

Four lines of evidence are available in the administrative record to assess this pollutant. Zero out of fourteen shellfish tissue samples exceeded the evaluation guideline applied to protect for the shellfish beneficial use. Zero of five dissolved water samples exceeded the evaluation guideline applied to protect estuarine habitat. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. Zero out of fourteen shellfish tissue samples exceeded the evaluation guideline. This does exceeds 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 Staff 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 99645, Cadmium
Region 3     
Morro Bay
 
LOE ID: 86
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: None of five samples taken in Morro Bay exceeded any CTR criteria for dissolved cadmium in saltwater. Cadmium concentrations ranged from 0.0686 to 0.0349 ug/L (Keeling, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain suspended material in concentrations that cause nuisance or adversely affect beneficial uses. Material Waters shall not contain settleable material in concentrations that result in deposition of material that causes nuisance or adversely affects beneficial uses.

Water quality objective in marine environment - total concentration 0.2 ppb.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline: CTR Saltwater acute 42 ug/L Criterion Maximum Concentration (CMC) and saltwater chronic 9.3 ug/L Criterion Continuous Concentration (CCC) criteria is applicable.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Water was sampled from five (5) separate locations representing the back, middle and front of the Bay including the inflows from the mouth Chorro and the mouth of Los Osos creeks that feed into the Bay. The stations were: Back Bay, Mouth Los Osos, Mouth Chorro, Middle Bay and Front Bay.
Temporal Representation: Water was sampled on March 8, 2001.
Environmental Conditions: This is one of five metals originally included in the 1996-303(d) metals listing. The listing was originally based on exceedances of Median International Standards (MIS) and Elevated Data Levels (EDL) guidelines for State Mussel Watch tissue data. The MIS and EDL guidelines do not meet the requirements of the Listing Policy.
QAPP Information: Battelle Laboratory Quality Assurance Plan.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 99645, Cadmium
Region 3     
Morro Bay
 
LOE ID: 55336
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The one sample did not exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. The three replicates were averaged prior to assessment.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for cadmium in shellfish tissue is 3.3 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 99645, Cadmium
Region 3     
Morro Bay
 
LOE ID: 77450
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The single result did not exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for cadmium in shellfish tissue is 3.3 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 99645, Cadmium
Region 3     
Morro Bay
 
LOE ID: 85
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 12
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: None of 12 samples from the 4 stations were in exceedance when the data was reevaluated using USEPA and OEHHA criteria (Keeling, S. 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline: USEPA standard of 4.0 ppm (wet weight) and OEHHA standard of 3.0 ppm (wet weight).
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Four sites were sampled on Morro Bay: 427.0, 428.5, 429.0, and 429.2.
Temporal Representation: Sampling occurred from 5-30-1980 to 1-20-1993.
Environmental Conditions: This is one of five metals originally included in the 1996-303(d) metals listing. The listing was originally based on exceedances of Median International Standards (MIS) and Elevated Data Levels (EDL) guidelines for State Mussel Watch tissue data. The MIS and EDL guidelines do not meet the requirements of the Listing Policy. Site 429.2, on 1/26/1987, 3/14/1988, 12/19/1988, 2/2/1990 and 1/20/1993 had levels over the MIS values (levels ranged from 1.01 - 1.23 ppm wet weight). Five out of five samples at site 429.2 were over MIS. One out of three samples were above MIS values at site 429.0 (6/28/1982, 1.17 ppm wet weight).
QAPP Information: State Mussel Watch Program Quality Assurance Plan.
QAPP Information Reference(s):
 
 
DECISION ID
83296
Region 3     
Morro Bay
 
Pollutant: Chlordane
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 section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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 out of two shellfish tissue samples exceeded the evaluation guideline. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. Zero out of two tissue samples exceeded the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 83296, Chlordane
Region 3     
Morro Bay
 
LOE ID: 55341
 
Pollutant: Chlordane
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The one sample did not exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. Total chlordane was calculated as the sum of the following chlordane isomers: cis- and trans-chlordane, cis- and trans-nonachlor, and oxychlordane.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for total chlordane in shellfish tissue is 6.0 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 83296, Chlordane
Region 3     
Morro Bay
 
LOE ID: 77451
 
Pollutant: Chlordane
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The single result did not exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011):  No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses.  There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for total chlordane in shellfish tissue is 6.0 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
 
DECISION ID
87187
Region 3     
Morro Bay
 
Pollutant: Chlorpyrifos
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.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero out of two shellfish tissue samples exceeded the evaluation guideline. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. Zero out of two shellfish tissue samples exceeded the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 87187, Chlorpyrifos
Region 3     
Morro Bay
 
LOE ID: 55342
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The one sample did not exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for chlorpyrifos in shellfish tissue is 1,000 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 87187, Chlorpyrifos
Region 3     
Morro Bay
 
LOE ID: 77452
 
Pollutant: Chlorpyrifos
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The single result did not exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011):  No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses.  There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for chlorpyrifos in shellfish tissue is 1,000 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
 
DECISION ID
83459
Region 3     
Morro Bay
 
Pollutant: Chromium
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5 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. Cadmium is one of five metals originally included in the 1996-303(d) metals listing. The listing was originally based on exceedances of Median International Standards (MIS) and Elevated Data Levels (EDL) guidelines for State Mussel Watch tissue data. The MIS and EDL guidelines do not meet the requirements of the Listing Policy. There are also no evaluation guideline for the dissolved fraction of chromium for the protection of aquatic life in marine waters that meets the requirements of the Listing Policy.

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 by it self on the section 303(d) list.

This conclusion is based on the staff findings that:

1.The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2.The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. None of the five samples taken can be compared with the established water quality objective because the established water quality objective available for comparison is in the total form of chromium and the available data is reported in the dissolved fraction. None of the 12 tissue samples could also not be evaluated because there is no numeric criteria or guideline that meets the requirements of the Listing Policy for chromium in tissue.

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: 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 Staff 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 83459, Chromium
Region 3     
Morro Bay
 
LOE ID: 87
 
Pollutant: Chromium (total)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: None of the 12 samples could be evaluated because there are no numeric criteria or guidelines that meets the requirements of the Listing Policy for chromium in tissue (Keeling, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline: There is no numeric criteria or guideline that meets the requirements of the Listing Policy for chromium in tissue.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Four sites were sampled on Morro Bay: 427.0, 428.5, 429.0, and 429.2.
Temporal Representation: Site 429.0 was sampled on 6/28/1982, 1/21/1983 and 5/3/1983. Site 429.2 was
sampled on 1/26/1987, 3/14/1988, 12/19/1988, 2/2/1990 and 1/20/1993. Sampling for all other sites occurred from 5-30-98 to 1-20-93.
Environmental Conditions: This is one of five metals originally included in the 1996-303(d) metals listing. The listing was originally based on exceedances of Median International Standards (MIS) and Elevated Data Levels (EDL) guidelines for State Mussel Watch tissue data. The MIS and EDL guidelines do not meet the requirements of the Listing Policy.
QAPP Information: State Mussel Watch Program Quality Assurance Plan.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 83459, Chromium
Region 3     
Morro Bay
 
LOE ID: 88
 
Pollutant: Chromium (total)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: None of the five samples taken can be compared with the established water quality objective because the established water quality objective is in the total form of chromium and the available data is reported in the dissolved fraction (Keeling, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline: There is no evaluation guideline for the dissolved fraction of chromium for the protection of aquatic like in marine waters that meets the requirements of the Listing Policy.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Water was sampled from five (5) separate locations representing the back, middle and front of the Bay including inflows from the mouth of Chorro and the mouth of Los Osos creeks that feed into the Bay. The stations are: Back Bay, Mouth Los Osos, Mouth Chorro, Middle Bay and Front Bay.
Temporal Representation: Water was sampled on March 8, 2001.
Environmental Conditions: This is one of five metals originally included in the 1996-303(d) metals listing. The listing was originally based on exceedances of Median International Standards (MIS) and Elevated Data Levels (EDL) guidelines for State Mussel Watch tissue data. The MIS and EDL guidelines do not meet the requirements of the Listing Policy.
QAPP Information: Battelle Laboratory Quality Assurance Plan.
QAPP Information Reference(s):
 
 
DECISION ID
83461
Region 3     
Morro Bay
 
Pollutant: Copper
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5 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. The CTR copper saltwater acute 4.8 ug/l Criterion Maximum Concentration (CMC) and saltwater chronic 3.1 ug/l Criterion Continuous Concentration (CCC) criteria as well as the copper USFWS effects value of 15 ppm (wet weight) are applicable.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list.

This conclusion is based on the staff findings that:

1.The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2.The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. None of the five water samples taken exceeded any of the CTR dissolved copper criteria in the water column. Dissolved copper concentrations ranged from 0.815 to0.262 ug/l. There were also no exceedances for the 12 copper samples in tissue. Tissue concentration measured from 0.76 to 3.13 ppm.

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: 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 Staff 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 83461, Copper
Region 3     
Morro Bay
 
LOE ID: 91
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: None of the five samples taken at the 5 stations exceeded any of the CTR dissolved copper criteria in the water column. Dissolved copper concentrations ranged from 0.815 to 0.262 μg/L (Keeling, S. 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain suspended material in concentrations that cause nuisance or adversely affect beneficial uses. Waters shall not contain settleable material in concentrations that result in deposition of material that causes nuisance or adversely affects beneficial uses. The CTR criteria for the dissolved fraction of copper is applicable for the protection of aquatic life.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline: CTR Saltwater acute 4.8 μg/L Criterion Maximum Concentration (CMC) and saltwater chronic 3.1 μg/L Criterion Continuous Concentration (CCC) criteria.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Water was sampled from five (5) separate locations representing the back, middle and front of the Bay including the inflows from the mouth Chorro and the mouth of Los Osos creeks that feed into the Bay. The stations are: Back Bay, Mouth Los Osos, Mouth Chorro, Middle Bay and Front Bay.
Temporal Representation: Water was sampled on March 8, 2001.
Environmental Conditions:
QAPP Information: Battelle Laboratory Quality Assurance Plan.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 83461, Copper
Region 3     
Morro Bay
 
LOE ID: 92
 
Pollutant: Copper
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Not Recorded
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 12
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: There were no exceedances of the 12 samples for copper in tissue for all 4 stations. Tissue concentration measured from 0.76 to 3.13 ppm (Keeling, S. 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline: US Fish and Wildlife Biological Effects value for copper is 15 ppm.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Four sites were sampled on Morro Bay: 427.0, 428.5, 429.0, and 429.2.
Temporal Representation: Sampling occurred from 5-30-1980 to 1-20-1993.
Environmental Conditions:
QAPP Information: State Mussel Watch Program Quality Assurance Plan.
QAPP Information Reference(s):
 
 
DECISION ID
83566
Region 3     
Morro Bay
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
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 section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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. The single shellfish tissue samples did not exceeded the evaluation guideline. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. The single shellfish tissue sample did not exceed the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 83566, DDT (Dichlorodiphenyltrichloroethane)
Region 3     
Morro Bay
 
LOE ID: 77453
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The single result did not exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. The total DDTs were calculated as the sum of 4,4- and 2,4- isomers of DDT, DDE, and DDD.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011):  No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses.  There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for total DDT in shellfish tissue is 23 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 83566, DDT (Dichlorodiphenyltrichloroethane)
Region 3     
Morro Bay
 
LOE ID: 55381
 
Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The one sample did not exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. Total DDT was calculated as the sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for total DDT in shellfish tissue is 23 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
 
DECISION ID
82983
Region 3     
Morro Bay
 
Pollutant: Diazinon
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 section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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. The single shellfish tissue sample did not exceed the evaluation guideline. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. The single shellfish tissue sample did not exceed the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 82983, Diazinon
Region 3     
Morro Bay
 
LOE ID: 55343
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The one sample did not exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for diazinon in shellfish tissue is 2,300 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
 
DECISION ID
82984
Region 3     
Morro Bay
 
Pollutant: Dieldrin
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 section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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 out of one shellfish tissue samples exceeded the evaluation guideline. One sample was not used in the assessment because the laboratory data reporting limit was above the objective and therefore the result could not be quantified with the level of certainty required by the Listing Policy. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. Zero out of one shellfish tissue samples exceeded the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 82984, Dieldrin
Region 3     
Morro Bay
 
LOE ID: 77454
 
Pollutant: Dieldrin
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The single result did not exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011):  No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses.  There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for dieldrin in shellfish tissue is 0.49 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 82984, Dieldrin
Region 3     
Morro Bay
 
LOE ID: 55348
 
Pollutant: Dieldrin
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: Zero of 0 samples exceeded the guideline. Each sample consisted of 45 California mussels. The one sample was not used in the assessment because the laboratory data reporting limit was above the objective and therefore the result could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for dieldrin in shellfish tissue is 0.49 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
 
DECISION ID
83032
Region 3     
Morro Bay
 
Pollutant: Endosulfan
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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 out of two shellfish tissue samples exceeded the evaluation guideline. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. Zero out of two shellfish tissue samples exceeded the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 83032, Endosulfan
Region 3     
Morro Bay
 
LOE ID: 55349
 
Pollutant: Endosulfan
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The one sample did not exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for endosulfan (l and ll) in shellfish tissue is 20,000 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 83032, Endosulfan
Region 3     
Morro Bay
 
LOE ID: 77455
 
Pollutant: Endosulfan
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The single result did not exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. Total Endosulfan result was calculated by summing Endosulfan I and Endosulfan II.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011):  No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses.  There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for endosulfan (l and ll) in shellfish tissue is 20,000 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
 
DECISION ID
83035
Region 3     
Morro Bay
 
Pollutant: Endrin
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 section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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 out of two shellfish tissue samples exceeded the evaluation guideline. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. Zero out of two shellfish tissue samples exceeded the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 83035, Endrin
Region 3     
Morro Bay
 
LOE ID: 55350
 
Pollutant: Endrin
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The one sample did not exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for endrin in shellfish tissue is 1,000 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 83035, Endrin
Region 3     
Morro Bay
 
LOE ID: 77456
 
Pollutant: Endrin
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The single result did not exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011):  No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses.  There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for endrin in shellfish tissue is 1,000 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
 
DECISION ID
82903
Region 3     
Morro Bay
 
Pollutant: Enterococcus
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.

One line of evidence is available in the administrative record to assess this pollutant. Thirty-eight of 463 samples exceeded the geometric mean standard for enterococcus for the water contact recreation water quality standard (USEPA Ambient Water Quality Criteria for Bacteria -1986).

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. Thirty-eight of 463 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 because applicable water quality standards are not being exceeded.
 
State Board Staff 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 82903, Enterococcus
Region 3     
Morro Bay
 
LOE ID: 47755
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 463
Number of Exceedances: 38
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Region 3 - Central Coast Region staff assessed R3 public submissions data for Morro Bay to determine beneficial use support and results are as follows: 38 of 463 samples exceed the criterion for Enterococci.
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 Enterococci in marine waters is 104 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 Morro Bay was collected at 12 monitoring sites [ 310BAY - Baywood Pier Beach, 310CIN - Cuesta Inlet Shoreline, 310COL - Coleman Beach, 310MID - Midway Seep, 310PAS - Pasadena Point, 310PSS - Pismo Seep, 310SIN - Sharks Inlet, shoreline, 310SPM - State Park Marina, 310TID - Tidelands Park Dock, 310TRN - Third Street Seep North, 310TRS - Third Street Seep South, 310WIN - Windy Cove]
Temporal Representation: Data was collected over the time period 3/7/2005 9:05:00 AM-2/16/2010 12:05:00 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
83088
Region 3     
Morro Bay
 
Pollutant: Heptachlor epoxide
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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 out of one shellfish tissue samples exceeded the evaluation guideline. The one sample was not used in the assessment because the laboratory data reporting limit was above the objective and therefore the result could not be quantified with the level of certainty required by the Listing Policy. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. Zero out of one shellfish tissue samples exceeded the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 83088, Heptachlor epoxide
Region 3     
Morro Bay
 
LOE ID: 55356
 
Pollutant: Heptachlor epoxide
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: Zero of 0 samples exceeded the guideline. Each sample consisted of 45 California mussels. The one sample was not used in the assessment because the laboratory data reporting limit was above the objective and therefore the result could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for heptachlor epoxide in shellfish tissue is 1.4 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 1999)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Public Health Goal for Heptachlor and Heptachlor Epoxide in Drinking Water
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 83088, Heptachlor epoxide
Region 3     
Morro Bay
 
LOE ID: 77458
 
Pollutant: Heptachlor epoxide
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The single result did not exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011):  No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses.  There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for heptachlor epoxide in shellfish tissue is 1.4 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 1999)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Public Health Goal for Heptachlor and Heptachlor Epoxide in Drinking Water
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
 
DECISION ID
83142
Region 3     
Morro Bay
 
Pollutant: Hexachlorobenzene/ HCB
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 section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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 out of two shellfish tissue samples exceeded the evaluation guideline. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. Zero out of two shellfish tissue samples exceeded the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 83142, Hexachlorobenzene/ HCB
Region 3     
Morro Bay
 
LOE ID: 55357
 
Pollutant: Hexachlorobenzene/ HCB
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The one sample did not exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for hexachlorobenzene in shellfish tissue is 4.3 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 2005)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 83142, Hexachlorobenzene/ HCB
Region 3     
Morro Bay
 
LOE ID: 77459
 
Pollutant: Hexachlorobenzene/ HCB
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The single result did not exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011):  No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses.  There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for hexachlorobenzene in shellfish tissue is 4.3 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 2005)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
 
DECISION ID
68936
Region 3     
Morro Bay
 
Pollutant: Lead
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5 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. There is no criteria or guideline available for lead in tissue that meets the requirements of the Listing Policy.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list.

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.No exceedances were recorded because there is no criteria or guideline available for lead in tissue that meets the requirements 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: 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 Staff 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 68936, Lead
Region 3     
Morro Bay
 
LOE ID: 98
 
Pollutant: Lead
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Not Recorded
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: No exceedances were recorded because there is no criteria or guideline available for lead in tissue that meets the requirements of the Listing Policy (Keeling, S. 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline: There is no criteria or guideline available for lead in tissue that meets the requirements of the Listing Policy.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: There were five sampling sites samples throughout Morro Bay. Locations represented the back, middle, and front of the Bay including inflows from Chorro and Los Osos Creeks.
Temporal Representation: Samples were taken on April 29 and May 4-5, 2002.
Environmental Conditions:
QAPP Information: State Mussel Watch Program Quality Assurance Plan.
QAPP Information Reference(s):
 
 
DECISION ID
83197
Region 3     
Morro Bay
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
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 section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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 out of two shellfish tissue samples exceeded the evaluation guideline. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. Zero out of two shellfish tissue samples exceeded the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 83197, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Region 3     
Morro Bay
 
LOE ID: 55358
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The one sample did not exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for lindane in shellfish tissue is 7.1 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 2005)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 83197, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Region 3     
Morro Bay
 
LOE ID: 77457
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The single result did not exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011):  No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses.  There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for lindane in shellfish tissue is 7.1 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 2005)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
 
DECISION ID
83300
Region 3     
Morro Bay
 
Pollutant: Mercury
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.5 of the Listing Policy. Under sections 3.1 and 3.5, 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. Mercury is one of five metals originally included in the 1996-303(d) metals listing. The listing was originally based on exceedances of Median International Standards (MIS) and Elevated Data Levels (EDL) guidelines for State Mussel Watch tissue data. The MIS and EDL guidelines do not meet the requirements of the Listing Policy. The CTR criteria for the dissolved fraction of selected metals are applicable for the protection of aquatic life but there is no CTR criterion for dissolved mercury in the saltwater column. However, OEHHA screening values are applicable for consumption of aquatic organisms. None of the 12 tissue samples exceeded the OEHHA screening value and none of the five water samples taken were in exceedance because there are no guidelines for dissolved mercury in the saltwater column that meet the requirements of the Listing Policy. Zero of one shellfish tissue samples exceed the evaluation guideline.

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 using table 3.1.

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 from the section 303(d) list.

This conclusion is based on the staff findings that:

1.The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2.The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. None of the 12 tissue samples exceeded the OEHHA screening value and none of the five water samples taken were in exceedance because there are no guidelines for dissolved mercury in the saltwater column that meet the requirements of the Listing Policy. Zero of one shellfish tissue samples exceed the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 83300, Mercury
Region 3     
Morro Bay
 
LOE ID: 90
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: None of the five samples taken in Morro Bay exceeded because there are no guidelines for dissolved mercury in the saltwater column that meet the requirements of the Listing Policy (Keeling, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain suspended material in concentrations that cause nuisance or adversely affect beneficial uses. Waters shall not contain settleable material in concentrations that result in deposition of material that causes nuisance or adversely affects beneficial uses.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline: There are no acute or chronic criteria for dissolved mercury in saltwater that meets the requirements of the Listing Policy.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Water was sampled from five (5) separate locations meant to represent the back, middle and front of the Bay and were also meant to represent the flow from the two creeks that feed the Bay (sites were Front Bay, Middle Bay, Back Bay, Mouth Chorro and Mouth Los Osos. The stations are: Back Bay, Mouth Los Osos, Mouth Chorro, Middle Bay and Front Bay.
Temporal Representation: Water was sampled on March 8, 2001.
Environmental Conditions:
QAPP Information: Battelle Laboratory Quality Assurance Plan.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 83300, Mercury
Region 3     
Morro Bay
 
LOE ID: 55366
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The one sample did not exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. The three replicates were averaged prior to assessment.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The USEPA 304(a) recommended water quality criterion for concentrations of methylmercury in shellfish tissue (wet weight) with a consumption rate of 21 g/day is 0.20 ppm. (Brodberg, R.K., and G.A. Pollock, 1999; USEPA, 2001)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Water Quality Criterion for the Protection of Human Health: Methylmercury. Final. United States Environmental Protection Agency Office of Science and Technology Office of Water. EPA-823-R-01-001. January 2001
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 83300, Mercury
Region 3     
Morro Bay
 
LOE ID: 89
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 12
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: None of the 12 samples exceeded the OEHHA screening value at the 4 sampling stations (Keeling, 2003).

This is one of five metals originally included in the 1996-303(d) metals listing. The listing was originally based on exceedances of Median International Standards (MIS) and Elevated Data Levels (EDL) guidelines for State Mussel Watch tissue data. The MIS and EDL guidelines do not meet the requirements of the Listing Policy. Two samples out of eight were found to be above the EDL 85 values (0.06 ppm) with concentrations of 0.136 ppm and 0.061 ppm wet weight on 1/26/1987 and 1/20/1993 respectively. Both samples were taken at site 429.2.
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline: OEHHA screening values of 0.3 ppm.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Four sites were sampled on Morro Bay: 427.0, 428.5, 429.0, and 429.2.
Temporal Representation: Sampling occurred from 5-30-1980 to 1-20-1993.
Environmental Conditions:
QAPP Information: State Mussel Watch Program Quality Assurance Plan.
QAPP Information Reference(s):
 
 
DECISION ID
83302
Region 3     
Morro Bay
 
Pollutant: Mirex
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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 out of zero shellfish tissue samples exceeded the evaluation guideline. The two samples were not used in the assessment because the laboratory data reporting limit was above the objective and therefore the result could not be quantified with the level of certainty required by the Listing Policy. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. Zero out of zero shellfish tissue samples exceeded the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 83302, Mirex
Region 3     
Morro Bay
 
LOE ID: 55367
 
Pollutant: Mirex
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: Zero of 0 samples exceeded the guideline. Each sample consisted of 45 California mussels. The one sample was not used in the assessment because the laboratory data reporting limit was above the objective and therefore the result could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for mirex in shellfish tissue is 0.43 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 1992)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Expedited Cancer Potency Values and Proposed Regulatory Levels for Certain Proposition 65 Carcinogens.
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 83302, Mirex
Region 3     
Morro Bay
 
LOE ID: 77460
 
Pollutant: Mirex
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The non detect result was not included in the assessment since the reporting limit was above the evaluation guideline. MDL were provided by NOAA Federal and RL were calculated by multiplying 3.18 by the MDL.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011):  No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses.  There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for mirex in shellfish tissue is 0.43 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 1992)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Expedited Cancer Potency Values and Proposed Regulatory Levels for Certain Proposition 65 Carcinogens.
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
 
DECISION ID
68264
Region 3     
Morro Bay
 
Pollutant: Nickel
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: No new data are assessed. This decision has not changed from the 2010 listing cycle.

This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. One line of evidence pertains to Nickel concentrations in the saltwater column, and the other pertains to Nickel concentrations in tissue. An insufficient number of samples exceed the CTR chronic-CCC criteria and there is no applicable guidelines to assess Nickel in tissue.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1.The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2.The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3.One of five samples exceeded the CTR chronic criteria and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using Table 3.1.
4.Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: 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 Staff 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 68264, Nickel
Region 3     
Morro Bay
 
LOE ID: 95
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Not Recorded
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: No standards exist. Tissue values ranged from 0.6 to 1.08 ppm for all 12 samples at all 4 sites (Keeling, S. 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline: There is no criteria or guideline for Nickel in tissue that meets the requirement of the Listing Policy.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Four sites were sampled on Morro Bay: 427.0, 428.5, 429.0, and 429.2.
Temporal Representation: Sampling occurred from 5-30-1980 to 1-20-1993.
Environmental Conditions:
QAPP Information: State Mussel Watch Quality Assurance Plan.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 68264, Nickel
Region 3     
Morro Bay
 
LOE ID: 94
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 5
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: One of five samples (at the mouth of Chorro Creek - 11.300 ug/l) exceeded the CTR-chronic CCC guideline and no sample exceeded the Acute CMC-CTR guideline concentration (Keeling, S. 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain suspended material in concentrations that cause nuisance or adversely affect beneficial uses. Waters shall not contain settleable material in concentrations that result in deposition of material that causes nuisance or adversely affects beneficial uses. Water quality objective in marine environment - total concentration 2 ppb.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline: CTR dissolved Nickel Saltwater acute is 74 ug/l (CMC) and saltwater chronic is 8.2 ug/l(CCC) criteria applicable for the protection of aquatic life in saltwater.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Water was sampled from five (5) separate locations representing the back, middle and front of the Bay including inflows from the mouth of the Chorro and the mouth of Los Osos creeks that that feed the Bay. The stations are: Back Bay, Mouth Los Osos, Mouth Chorro, Middle Bay and Front Bay.
Temporal Representation: Water was sampled on March 8, 2001.
Environmental Conditions:
QAPP Information: Battelle Laboratory Quality Assurance Plan.
QAPP Information Reference(s):
 
 
DECISION ID
83358
Region 3     
Morro Bay
 
Pollutant: PAHs (Polycyclic Aromatic Hydrocarbons)
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 section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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. One out of two shellfish tissue samples exceeded the evaluation guideline. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. One out of two shellfish tissue samples exceeded the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 83358, PAHs (Polycyclic Aromatic Hydrocarbons)
Region 3     
Morro Bay
 
LOE ID: 55369
 
Pollutant: PAHs (Polycyclic Aromatic Hydrocarbons)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The sample did not exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. PAH, Total is calculated as a potency weighted concentration with respect to benzo(a)pyrene and was calculated based on the following analytes: Dibenz(a,h)anthracene, Benzo(a)pyrene, Benz(a)anthracene, Benzo(b)fluoranthene, Benzo(k)fluoranthene, Indeno(1,2,3-c,d)pyrene, Anthracene, Benzo(g,h,i)perylene, Chrysene, Acenaphthene, Acenaphthylene, Fluoranthene, Fluorene, Phenanthrene, and Pyrene.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for polycyclic aromatic hydrocarbons in shellfish tissue is 1.1 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 83358, PAHs (Polycyclic Aromatic Hydrocarbons)
Region 3     
Morro Bay
 
LOE ID: 77461
 
Pollutant: PAHs (Polycyclic Aromatic Hydrocarbons)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The non detect result was not included in the assessment since the reporting limit was above the evaluation guideline. MDL were provided by NOAA Federal and RL were calculated by multiplying 3.18 by the MDL.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for polycyclic aromatic hydrocarbons in shellfish tissue is 1.1 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
 
DECISION ID
73119
Region 3     
Morro Bay
 
Pollutant: PCBs (Polychlorinated biphenyls)
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 section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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. One out of two shellfish tissue samples exceeded the evaluation guideline. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. One out of two shellfish tissue samples exceeded the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 73119, PCBs (Polychlorinated biphenyls)
Region 3     
Morro Bay
 
LOE ID: 77462
 
Pollutant: PCBs (Polychlorinated biphenyls)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The single result did exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. Total PCB was assessed for as follows: PCB aroclors and congeners were summed separately and the sum that yielded the highest value was used for the assessment.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for polychlorinated biphenyls in shellfish tissue is 3.9 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 73119, PCBs (Polychlorinated biphenyls)
Region 3     
Morro Bay
 
LOE ID: 55379
 
Pollutant: PCBs (Polychlorinated biphenyls)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The one sample did not exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. Total PCB was assessed for as follows: PCB aroclors and congeners were summed separately and the sum that yielded the highest value was used for the assessment.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for polychlorinated biphenyls in shellfish tissue is 3.9 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
 
DECISION ID
83360
Region 3     
Morro Bay
 
Pollutant: Selenium
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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. One out of two shellfish tissue samples exceeded the evaluation guideline. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. One out of two shellfish tissue samples exceeded the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 83360, Selenium
Region 3     
Morro Bay
 
LOE ID: 55380
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The one sample did not exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. The three replicates were averaged prior to assessment.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for selenium in shellfish tissue is 11 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. A background dietary consumption rate of 0.114 mg/day is applied for this micronutrient. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 83360, Selenium
Region 3     
Morro Bay
 
LOE ID: 77463
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The single result did not exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for selenium in shellfish tissue is 11 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. A background dietary consumption rate of 0.114 mg/day is applied for this micronutrient. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
 
DECISION ID
83414
Region 3     
Morro Bay
 
Pollutant: Toxaphene
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 section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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 zero shellfish tissue samples exceeded the evaluation guideline. The one sample was not used in the assessment because the laboratory data reporting limit was above the objective and therefore the result could not be quantified with the level of certainty required by the Listing Policy. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. Zero of zero shellfish tissue samples exceeded the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 83414, Toxaphene
Region 3     
Morro Bay
 
LOE ID: 55390
 
Pollutant: Toxaphene
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: Zero of 0 samples exceeded the guideline. Each sample consisted of 45 California mussels. The one sample was not used in the assessment because the laboratory data reporting limit was above the objective and therefore the result could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for toxaphene in shellfish tissue is 6.5 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
 
DECISION ID
83466
Region 3     
Morro Bay
 
Pollutant: Tributyltin TBT (Tributylstanne)
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 section 303(d) list under section 3.5 of the Listing Policy. Under section 3.5, 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. The single shellfish tissue sample did not exceed the evaluation guideline. 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. The single shellfish tissue sample did not exceed the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.

4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Staff 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 83466, Tributyltin TBT (Tributylstanne)
Region 3     
Morro Bay
 
LOE ID: 55391
 
Pollutant: Tributyltin TBT (Tributylstanne)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The one sample did not exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for tributyltin in shellfish tissue is 1 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
 
DECISION ID
68417
Region 3     
Morro Bay
 
Pollutant: Vanadium (fume or dust)
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: No new data are assessed. This decision has not changed from the 2010 listing cycle.

This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. It is not possible to determine exceedances of any standard because there are no guidelines for dissolved Vanadium in the saltwater column for the protection of aquatic life or any applicable guideline for Vanadium in tissue that meets the requirements of the Listing Policy.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1.The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2.The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3.A guideline for vanadium is not available that complies with the requirements of section 6.1.3 of the 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: 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 Staff 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 68417, Vanadium (fume or dust)
Region 3     
Morro Bay
 
LOE ID: 96
 
Pollutant: Vanadium (fume or dust)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: None of the five samples taken were found to exceed because there is no criterion or guideline for dissolved Vanadium in the saltwater column for the protection of aquatic life that meets the requirements of the Listing Policy (Keeling, S. 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain suspended material in concentrations that cause nuisance or adversely affect beneficial uses. Waters shall not contain settleable material in concentrations that result in deposition of material that causes nuisance or adversely affects beneficial uses.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Water was sampled from five (5) separate locations representing the back, middle and front of the Bay including inflow from the mouth Chorro and mouth Los Osos creeks that feed into the Bay. The stations are: Back Bay, Mouth Los Osos, Mouth Chorro, Middle Bay and Front Bay.
Temporal Representation: Water was sampled on March 8, 2001.
Environmental Conditions:
QAPP Information: Battelle Laboratory Quality Assurance Plan.
QAPP Information Reference(s):
 
 
DECISION ID
80882
Region 3     
Morro Bay
 
Pollutant: Zinc
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: No new data are assessed. This decision has not changed from the 2010 listing cycle.

This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. None of the samples in the water column exceed any of the CTR criteria for dissolved Zinc for the protection of aquatic life. In addition there is no criteria or guideline for Zinc in tissue that meets the requirements of the Listing Policy.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1.The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2.The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3.No samples exceeded any of the CTR criteria for the protection of aquatic life in the saltwater column. In addition, it was not possible to evaluate zinc in tissue samples because there is no guideline that meets the requirement of the Listing. The sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using Table 3.1.
4.Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: 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 Staff 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 80882, Zinc
Region 3     
Morro Bay
 
LOE ID: 97
 
Pollutant: Zinc
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: None of the five samples taken in Morro Bay exceeded any of the dissolved zinc acute or chronic criteria (Keeling, S. 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain suspended material in concentrations that cause nuisance or adversely affect beneficial uses. Waters shall not contain settleable material in concentrations that result in deposition of material that causes nuisance or adversely affects beneficial uses.

Water quality objective in marine environment - total concentration 20 ppb.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline: Dissolved Zinc CTR Saltwater acute (CMC) criterion is 90 ug/L and saltwater chronic (CCC) criterion is 81 ug/L for the protection of aquatic life in the water column.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Water was sampled from five (5) separate locations representing the back, middle and front of the Bay including inflows from the mouth of Chorro and the mouth of Los Osos creeks that feed the Bay. The stations are: Back Bay, Mouth Los Osos, Mouth Chorro, Middle Bay and Front Bay.
Temporal Representation: Water was sampled on March 8, 2001.
Environmental Conditions:
QAPP Information: Battelle Laboratory Quality Assurance Plan.
QAPP Information Reference(s):
 
 
DECISION ID
83191
Region 3     
Morro Bay
 
Pollutant: Arsenic
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: Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.5 of the Listing Policy. Under section 3.1, a single line of evidence is necessary to assess listing status. Under section 3.5, one line of evidence is necessary to assess listing status.

Four lines of evidence are available in the administrative record to assess this pollutant. Two out of two shellfish tissue samples exceeded the evaluation guideline applied to protect for the shellfish beneficial use. Zero of two shellfish tissue samples exceed the evaluation guideline applied to protect for the commercial beneficial use. Zero of five dissolved water samples exceeded the evaluation guideline applied to protect estuarine habitat. For water samples, 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 using table 3.1.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:

1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.

3. Two out of two shellfish tissue samples exceeded the evaluation guideline. This does exceeds 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 be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Staff 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 83191, Arsenic
Region 3     
Morro Bay
 
LOE ID: 55335
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Region 3 Harbor Study Project data for Morro Bay to determine beneficial use support and results are as follows: The one sample did exceed the guideline. Each sample consisted of 45 California mussels. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. Ten percent of the total arsenic result was used to estimate of the amount of inorganic arsenic in the sample; this number was screened against the guideline. The three replicates were averaged prior to assessment.
Data Reference: Harbor Study 2004
  Environmental condition of water, sediment, and tissue quality in Central Coast harbors
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for arsenic in shellfish tissue is 0.0052 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 2004)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.
 
Spatial Representation: A sample was collected from station 310MORO01. The sample for station 310MORO19 was missing. Mussels were deployed at one station in the back of the harbor and one station at the front (or most seaward) portion of the harbor within the waterbody.
Temporal Representation: Mussels were deployed February 17-19, 2004 and retrieved June 21-25, 2004.
Environmental Conditions:
QAPP Information: Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
Line of Evidence (LOE) for Decision ID 83191, Arsenic
Region 3     
Morro Bay
 
LOE ID: 77449
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Shellfish
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Shellfish surveys
Data Used to Assess Water Quality: Water Board staff assessed Mussel Watch Project data for Morro Bay to determine beneficial use support and results are as follows: The single result did exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. Ten percent of the total arsenic result was used to estimate of the amount of inorganic arsenic in the sample; this number was screened against the guideline.
Data Reference: State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the Central Coastal Basin (2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for arsenic in shellfish tissue is 0.0052 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 2004)
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
  Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
  Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.
 
Spatial Representation: Samples are collected by hand from three sub-locations for each site. The composite sample was collected from site MBVG.
Temporal Representation: Representative samples of locally abundant species were collected during the winter on 3/23/2009
Environmental Conditions:
QAPP Information: "Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/"
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 83191, Arsenic
Region 3     
Morro Bay
 
LOE ID: 83
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Evaluation of the inorganic arsenic clam tissue data using the USEPA criteria resulted in 2 of 2 samples not exceeding the criteria. Sampling station 429.0, outside of the mouth of the Bay recorded levels of 0.145 ppm and 0.174 ppm inorganic arsenic. Tissue were measured at 1.45 and 1.74 ppm as total arsenic (Keeling, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline: The USEPA criteria for inorganic arsenic is 1.2 ppm wet weight and the OEHHA criteria is 1.0 ppm wet weight for total arsenic.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Four sites were sampled on Morro Bay. One station was evaluated for this listing: 429.0. There were a total of 4 sampling stations: 427.0, 428.5, 429.0 and 429.2.
Temporal Representation: Site 429.0 was sampled on 6/28/1982, 1/21/1983 and 5/3/1983. Sampling for the remaining three stations occurred from 5-30-1980 to 1-20-1993.
Environmental Conditions: This is one of five metals originally included in the 1996-303(d) metals listing. The listing was originally based on exceedances of Median International Standards (MIS) and Elevated Data Levels (EDL) guidelines for State Mussel Watch tissue data. The MIS and EDL guidelines do not meet the requirements of the Listing Policy.
QAPP Information: State Mussel Watch Program Quality Assurance Plan.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 83191, Arsenic
Region 3     
Morro Bay
 
LOE ID: 84
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: None of the five samples taken at the 5 stations exceeded any of the CTR dissolved arsenic criteria in the water column (Keeling, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain suspended material in concentrations that cause nuisance or adversely affect beneficial uses. Waters shall not contain settleable material in concentrations that result in deposition of material that causes nuisance or adversely affects beneficial uses.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline: CTR saltwater acute 69 ug/l Criterion Maximum Concentration (CMC) and saltwater chronic 36 ug/l Criterion Continuous Concentration (CCC) criteria are applicable for the protection of aquatic life.
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Water was sampled from five (5) separate locations representing the back, middle and front of the Bay including inflows from the mouths of Chorro and Los Osos Creeks who each feed the Bay. These stations were: Back Bay, Mouth Los Osos, Mouth Chorro, Middle Bay and Front Bay.
Temporal Representation: Water was sampled on March 8, 2001.
Environmental Conditions:
QAPP Information: Battelle Laboratory Quality Assurance Plan.
QAPP Information Reference(s):
 
 
DECISION ID
68706
Region 3     
Morro Bay
 
Pollutant: Indicator Bacteria
Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status Original
Sources: Boat Discharges/Vessel Wastes | Domestic Pet Waste | Groundwater Loadings | Natural Sources | Onsite Wastewater Systems (Septic Tanks) | Other | 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. The decision has not changed.

Note the pollutant name has been changed from Pathogens to Indicator Bacteria

This pollutant is being considered for listing under section 2.2 of the Listing Policy. Under this section of the Policy, a minimum of one line of evidence is needed to assess listing status. The Morro Bay Pathogens TMDL was approved by RWQCB on May 16, 2003 and subsequently approved by USEPA on January 20, 2004. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination in the Water Quality Limited Segments Being Addressed portion of the section 303(d) list.
 
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 Staff 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 68706, Indicator Bacteria
Region 3     
Morro Bay
 
LOE ID: 78
 
Pollutant: Pathogens
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
68652
Region 3     
Morro Bay
 
Pollutant: Sedimentation/Siltation
Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status Original
Sources: Agriculture | Erosion/Siltation | Grazing-Related Sources | Habitat Modification | Highway/Road/Bridge Construction | Land Development
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 listing under section 2.2 of the Listing Policy. Under this section of the Policy, a minimum of one line of evidence is needed to assess listing status.

The Morro Bay Sediment TMDL was approved by RWQCB on May 16, 2003 and subsequently approved by USEPA on January 20, 2004.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination in the Water Quality Limited Segments Being Addressed portion of the section 303(d) list.
 
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 Staff 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 68652, Sedimentation/Siltation
Region 3     
Morro Bay
 
LOE ID: 77
 
Pollutant: Sedimentation/Siltation
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: Placeholder reference 2006 303(d)
 
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):