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

Supporting Information

Regional Board 2 - San Francisco Bay Region

Water Body Name: Napa River, non-tidal
Water Body ID: CAR2065002020160701061256
Water Body Type: River & Stream
 
DECISION ID
89762
Region 2     
Napa River, non-tidal
 
Pollutant: Nutrients
Final Listing Decision: 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 Revised
Reason for Delisting: Applicable WQS attained; reason for recovery unspecified
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 4.11 of the Listing Policy. Under this section when all other delisting factors do not result in the delisting of a water segment but information indicates attainment of standards, a water segment shall be evaluated to determine whether the weight of evidence demonstrates that water quality standard is attained. If the weight of evidence indicates attainment, the water segment shall be removed from the CWA section 303(d) List.

The evaluation of eutrophic conditions requires the weight of evidence approach because the evaluation process examining a stream¿s trophic status requires measuring naturally occurring stream organisms (i.e., algae) and determining if the current amount of algae is affecting recreational beneficial uses or water quality parameters that influence aquatic life (e.g., pH and dissolved oxygen). Such an analysis requires the integration of secondary water quality indicators at sites with high algal biomass because the presence of algae alone does not demonstrate that aquatic impacts have occurred.

The datasets used to evaluate nutrient impairment in the non-tidal portion of Napa River are both spatially representative of the watershed and span a decade. Staff compiled nutrient chemistry data from 2002-2004, 2009, and 2011-2012. We developed benthic algae-based lines of evidence using data collected most recently in 2011 and 2012, which represent current conditions in the watershed. Therefore, this dataset meets the spatial and temporal Listing Policy requirements.

We used two lines of evidence (i.e., benthic chlorophyll a, benthic percent macroalgae cover) to directly quantify the amount of algae in the stream, in order to determine if the narrative water quality objective for biostimulatory substances (i.e., eutrophication) is currently exceeded. Both metrics show a low proportion of exceedance, but there are not enough samples to use the binomial approach in Tables 4.1 or 4.2 of the Listing Policy.

For the eutrophication-based lines of evidence (i.e., chlorophyll a and percent macroalgae cover) we collected 16 benthic chlorophyll a, 17 macroalgae percent cover. However, these measures are fairly consistent over time, so they take into account water quality conditions for weeks to months around the sample date. The temporally integrative nature of the algal biomass lines of evidence is supported by growth rates of algae, and the minor change in percent algae cover observed across the summer in 2012 at six sites. As a result, we are confident that the weight of evidence approach is appropriate for this analysis. For the four lines of evidence regarding nutrients with direct toxic effects (e.g., un-ionized ammonia, total ammonia, nitrite, and nitrate + nitrite), we used Listing Policy Table 4.1 criteria for toxicants to show that exceedances have been below the maximum number of exceedances allowed to remove a water segment and that municipal, agricultural, and aquatic life beneficial uses were not affected by nutrient toxicity.

The nuisance algae indicators showed that the River is not impaired for nutrients because they had a low rate of exceedance of the applicable guidelines; for those instances, the secondary indicators were not consistently exceeded. Of the samples collected in 2011 and 2012, we observed two (12.5 percent) exceedances for chlorophyll a based on the Cold Freshwater Habitat beneficial use threshold of 150 mg/m2, and two exceedances (11.8 percent) of the percent filamentous cover threshold of 30 percent. At the three sampling locations where we observed exceedances of these evaluation guidelines, the alternate algae indicator and secondary indicators (e.g., pH ) showed that potentially impacted beneficial uses were not affected by nutrients.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for removing this water segment-pollutant combination from the 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 following information indicates that the water quality standard is attained:
2 of 16 samples exceeded the evaluation guideline for benthic algae concentration. To use section 4.2, we would require a minimum of 26 samples so there is insufficient information to evaluate this line of evidence. Current conditions indicate that this evaluation guideline is exceeded a small proportion of the time despite not having 26 samples required for de-listing using binomial distribution requirements of the Listing Policy.
2 of 17 samples exceeded the evaluation guideline for percent cover of benthic algae. To use section 4.2, we would require a minimum of 26 samples so there is insufficient information to evaluate this line of evidence. Current conditions indicate that this evaluation guideline is exceeded a small proportion of the time despite not having 26 samples required for de-listing using binomial distribution requirements of the Listing Policy.
0 of 6 samples exceeded the evaluation guideline for un-ionized ammonia. To use section 4.2, we would require a minimum of 26 samples so there is insufficient information to evaluate this line of evidence. Current conditions indicate that this evaluation guideline is exceeded a small proportion of the time despite not having 26 samples required for de-listing using binomial distribution requirements of the Listing Policy.
0 of 120 samples exceeded the evaluation guideline for nitrogen as nitrate+nitrite. This number of exceedances meets the requirements for de-listing according to section 4.1 of the Listing Policy.
0 of 120 samples exceeded the evaluation guideline for nitrogen as nitrite. This number of exceedances meets the requirements for de-listing according to section 4.1 of the Listing Policy.
0 of 120 samples exceeded the evaluation guideline for nitrogen as total ammonia. This number of exceedances meets the requirements for de-listing according to section 4.1 of the Listing Policy.
0 of 27 samples exceeded the evaluation guideline for pH. This number of exceedances meets the requirements for de-listing according to section 4.2 of the Listing Policy.


3. This process is scientifically defensible and reproducible.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be removed from the section 303(d) list because applicable water quality standards for the pollutant are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation: Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for removing this water segment-pollutant combination from the 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 following information indicates that the water quality standard is attained:
2 of 16 samples exceeded the evaluation guideline for benthic algae concentration. To use section 4.2, we would require a minimum of 26 samples so there is insufficient information to evaluate this line of evidence. Current conditions indicate that this evaluation guideline is exceeded a small proportion of the time despite not having 26 samples required for de-listing using binomial distribution requirements of the Listing Policy.
2 of 17 samples exceeded the evaluation guideline for percent cover of benthic algae. To use section 4.2, we would require a minimum of 26 samples so there is insufficient information to evaluate this line of evidence. Current conditions indicate that this evaluation guideline is exceeded a small proportion of the time despite not having 26 samples required for de-listing using binomial distribution requirements of the Listing Policy.
0 of 6 samples exceeded the evaluation guideline for un-ionized ammonia. To use section 4.2, we would require a minimum of 26 samples so there is insufficient information to evaluate this line of evidence. Current conditions indicate that this evaluation guideline is exceeded a small proportion of the time despite not having 26 samples required for de-listing using binomial distribution requirements of the Listing Policy.
0 of 120 samples exceeded the evaluation guideline for nitrogen as nitrate+nitrite. This number of exceedances meets the requirements for de-listing according to section 4.1 of the Listing Policy.
0 of 120 samples exceeded the evaluation guideline for nitrogen as nitrite. This number of exceedances meets the requirements for de-listing according to section 4.1 of the Listing Policy.
0 of 120 samples exceeded the evaluation guideline for nitrogen as total ammonia. This number of exceedances meets the requirements for de-listing according to section 4.1 of the Listing Policy.
0 of 27 samples exceeded the evaluation guideline for pH. This number of exceedances meets the requirements for de-listing according to section 4.2 of the Listing Policy.


3. This process is scientifically defensible and reproducible.
 
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 89762, Nutrients
Region 2     
Napa River, non-tidal
 
LOE ID: 96636
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 120
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Data consists of 120 samples collected during 2002, 2003, 2004, 2009, 2011, and 2012. None of the 120 samples exceeded the objective.
Data Reference: Staff Report to Support Delisting of Napa River and Sonoma Creek for Nutrients
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The San Francisco Basin Water Quality Control Plan (Basin Plan) has a water quality objective for nitrate plus nitrite of 10.0 mg/L (as nitrogen) to protect the municipal supply beneficial use.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from the following 38 stations on Napa River and its tributaries.Dry Ck. @ Railroad Bridge, Mill Ck. @ the old Bale Mill, Ritchey Ck. nr. Ranger Station, Napa Ck. @ Jefferson, Napa R. @ Calistoga Community Center, Napa R. @ Zinfandel Lane, Napa R. @ Tubbs Lane, Napa R. @ Yountville Ecopreserve, Tulukay Ck. @ Terrace Court, Murphy Ck. @ "Stone Bridge" on Coombsville Road, Carneros Ck. @ Withers, Salvadore channel @ Garfield Park, Milliken Ck. @ Hedgeside Avenue
Brown Valley Ck. @ "Little Stone Bridge", Fagan Ck. @ Kelly Rd., Soda Ck. @ Silverado Trail
Napa R. @ Trancas St., Sulphur Ck. @ Lower Bridge near Trailer Park , Bell Canyon Ck. @ Silverado
Dutch Henry Ck. @ Larkmead Lane Bridge, Napa R. @ 3rd St.,Napa R. @ Oak Knoll Ave.
Redwood Ck. @ Redwood Road, Browns Valley Ck. @ Buhman Ave., Browns Valley Ck. @ Morningside Dr.,Murphy Ck. @ Shadybrook Ln., Tulukay Ck. @ Shurtleff Ave. (close to N11)
Napa R. @ Heather Oaks Park, Napa R. @ Dunaweal Ln., Napa R. @ Larkmead Ln., Bell Canyon Ck. @ Crystal Springs Rd., Canon Ck. @322 Glass Mountain Rd., Napa R. @ Lodi Ln.,Napa R. @ Pope St. Saint Helena, Salvadore Channel @ 2280 Dry Ck. Rd., Salvadore Channel @ 121 near school
Shehey Creek @ N Kelly Road & Executive way (Sh-1), Napa River at Frogs Leap
Temporal Representation: Samples were collected during 2002, 2003, 2004, 2009, 2011, and 2012.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Some data were collected by Water Board staff following SWAMP Standard Operating Procedures and SWAMP Quality Assurance program Plan (QAPrP) (2008) and are SWAMP compliant, other data were collected by the San Francisco Estuary Institute.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 89762, Nutrients
Region 2     
Napa River, non-tidal
 
LOE ID: 96638
 
Pollutant: Algae
LOE Subgroup: Pollutant-Nuisance
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 16
Number of Exceedances: 2
 
Data and Information Type: Occurrence of conditions judged to cause impairment
Data Used to Assess Water Quality: The data consist of benthic chlorophyll-a samples collected according to the SWAMP bioassessment protocol (Fetscher et al. 2009). Two of the 16 benthic chlorophyll-a samples exceeded the evaluation guideline.
Data Reference: DRAFT SWAMP Reachwide Benthos Method for Stream Algae Sampling and Associated Physical Habitat Data Collection. Version 6
  Staff Report to Support Delisting of Napa River and Sonoma Creek for Nutrients
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan for the San Francisco Bay Basin states that waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The Technical Approach to Develop Nutrient Numeric Endpoints for California. (Tetra Tech 2006) suggests that concentrations of benthic algae above 150 mg/m2 are presumed to be impaired for Cold Freshwater Habitat. This concentration represents the threshold above which the risk of beneficial use impairment by nutrients is probable.
Guideline Reference: Technical Approach to Develop Nutrient Numeric Endpoints for California
 
Spatial Representation: Benthic chlorophyll-a data were collected from the following 10 stations on Napa River: Mill Ck. @ the old Bale Mill, Ritchey Ck. nr. Ranger Station, Napa R. @ Zinfandel Lane, Napa R. @ Yountville Ecopreserve, Tulukay Ck. @ Terrace Court (close to N 44), Redwood Ck. @ Redwood Road, Napa R. @ Dunaweal Ln., Napa R. @ Pope St. Saint Helena, Salvadore Channel @ 121 near school, Napa River at Frogs Leap
Temporal Representation: Samples were collected in August/September 2011, and August/September 2012.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: All data was collected following SWAMP Standard Operating Procedures and SWAMP Quality Assurance program Plan (QAPrP) (2008) and are considered SWAMP compliant.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 89762, Nutrients
Region 2     
Napa River, non-tidal
 
LOE ID: 96637
 
Pollutant: Algae
LOE Subgroup: Pollutant-Nuisance
Matrix: Water
Fraction: Percent
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 17
Number of Exceedances: 2
 
Data and Information Type: HABITAT ASSESSMENT
Data Used to Assess Water Quality: The percent cover data were collected according to the SWAMP Standard Operating Procedures for Collecting Stream Algae Samples and Associated Physical Habitat and Chemical Data for Ambient Bioassessments in California (Fetscher et al. 2009). According to this method, the presence of attached or un-attached macroalgae is observed at 105 systematic points along the stream reach. The number of observed points with either attached or un-attached macroalgae out of the 105 inspected points is used to determine the percent macroalgae cover for the 150m section of stream. Two of the 17 samples exceeded the evaluation guideline for percent macroalgae cover.
Data Reference: DRAFT SWAMP Reachwide Benthos Method for Stream Algae Sampling and Associated Physical Habitat Data Collection. Version 6
  Staff Report to Support Delisting of Napa River and Sonoma Creek for Nutrients
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan for the San Francisco Bay Basin states that waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: Biggs (2000) recommends a 30 percent cover by filamentous green or brown algae as a threshold associated with benthic chlorophyll-a levels consistent with protection of recreation and fisheries.
Guideline Reference: New Zealand Periphyton Guideline: Detecting Monitoring and Managing Enrichment of Streams
 
Spatial Representation: Percent algae cover data were collected from the following 10 stations on Napa River: Mill Ck. @ the old Bale Mill, Ritchey Ck. nr. Ranger Station, Napa R. @ Zinfandel Lane, Napa R. @ Yountville Ecopreserve, Tulukay Ck. @ Terrace Court (close to N 44), Redwood Ck. @ Redwood Road, Napa R. @ Dunaweal Ln., Napa R. @ Pope St. Saint Helena, Salvadore Channel @ 121 near school, Napa River at Frogs Leap
Temporal Representation: Samples were collected in August/September 2011, and August/September 2012.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: All data was collected following SWAMP Standard Operating Procedures and SWAMP Quality Assurance program Plan (QAPrP) (2008) and are considered SWAMP compliant.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 89762, Nutrients
Region 2     
Napa River, non-tidal
 
LOE ID: 96633
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Annual medians computed from 120 samples collected during 2002, 2003, 2004, 2009, 2011, and 2012. None of the six annual medians exceeded the objective.
Data Reference: Staff Report to Support Delisting of Napa River and Sonoma Creek for Nutrients
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin General Objective, Chapter III, Section 3.3.20. The discharge of wastes shall not cause receiving waters to contain annual median concentrations of un-ionized ammonia in excess 0.025 mg/l as N.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from the following 38 stations on Napa River and its tributaries.Dry Ck. @ Railroad Bridge, Mill Ck. @ the old Bale Mill, Ritchey Ck. nr. Ranger Station, Napa Ck. @ Jefferson, Napa R. @ Calistoga Community Center, Napa R. @ Zinfandel Lane, Napa R. @ Tubbs Lane, Napa R. @ Yountville Ecopreserve, Tulukay Ck. @ Terrace Court, Murphy Ck. @ "Stone Bridge" on Coombsville Road, Carneros Ck. @ Withers, Salvadore channel @ Garfield Park, Milliken Ck. @ Hedgeside Avenue
Brown Valley Ck. @ "Little Stone Bridge", Fagan Ck. @ Kelly Rd., Soda Ck. @ Silverado Trail
Napa R. @ Trancas St., Sulphur Ck. @ Lower Bridge near Trailer Park , Bell Canyon Ck. @ Silverado
Dutch Henry Ck. @ Larkmead Lane Bridge, Napa R. @ 3rd St.,Napa R. @ Oak Knoll Ave.
Redwood Ck. @ Redwood Road, Browns Valley Ck. @ Buhman Ave., Browns Valley Ck. @ Morningside Dr.,Murphy Ck. @ Shadybrook Ln., Tulukay Ck. @ Shurtleff Ave. (close to N11)
Napa R. @ Heather Oaks Park, Napa R. @ Dunaweal Ln., Napa R. @ Larkmead Ln., Bell Canyon Ck. @ Crystal Springs Rd., Canon Ck. @322 Glass Mountain Rd., Napa R. @ Lodi Ln.,Napa R. @ Pope St. Saint Helena, Salvadore Channel @ 2280 Dry Ck. Rd., Salvadore Channel @ 121 near school
Shehey Creek @ N Kelly Road & Executive way (Sh-1), Napa River at Frogs Leap
Temporal Representation: Samples were collected during 2002, 2003, 2004, 2009, 2011, and 2012.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Some data were collected by Water Board staff following SWAMP Standard Operating Procedures and SWAMP Quality Assurance program Plan (QAPrP) (2008) and are SWAMP compliant, other data were collected by the San Francisco Estuary Institute.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 89762, Nutrients
Region 2     
Napa River, non-tidal
 
LOE ID: 96632
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 27
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Numeric data generated from 27 minimums and maximums had 0 exceedances.
Data Reference: Staff Report to Support Delisting of Napa River and Sonoma Creek for Nutrients
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The pH shall not be depressed below 6.5 nor raised above 8.5.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from the following 11 stations on Napa River: Mill Ck. @ the old Bale Mill, Ritchey Ck. nr. Ranger Station, Napa R. @ Zinfandel Lane, Napa R. @ Yountville Ecopreserve, Tulukay Ck. @ Terrace Court (close to N 44), Napa R. @ Oak Knoll Ave., Redwood Ck. @ Redwood Road, Napa R. @ Dunaweal Ln., Napa R. @ Pope St. Saint Helena, Salvadore Channel @ 121 near school, Napa River at Frogs Leap
Temporal Representation: Samples were collected in August/September 2011, June 2012, and August/September 2012.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: All data was collected following SWAMP Standard Operating Procedures and SWAMP Quality Assurance program Plan (QAPrP) (2008) and are considered SWAMP compliant.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 89762, Nutrients
Region 2     
Napa River, non-tidal
 
LOE ID: 96635
 
Pollutant: Nitrogen, Nitrite
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 120
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Data consists of 120 samples collected during 2002, 2003, 2004, 2009, 2011, and 2012. None of the 120 samples exceeded the objective.
Data Reference: Staff Report to Support Delisting of Napa River and Sonoma Creek for Nutrients
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The San Francisco Basin Water Quality Control Plan (Basin Plan) has a water quality objective for nitrite of 1.0 mg/L (as nitrogen) to protect the municipal supply beneficial use.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from the following 38 stations on Napa River and its tributaries.Dry Ck. @ Railroad Bridge, Mill Ck. @ the old Bale Mill, Ritchey Ck. nr. Ranger Station, Napa Ck. @ Jefferson, Napa R. @ Calistoga Community Center, Napa R. @ Zinfandel Lane, Napa R. @ Tubbs Lane, Napa R. @ Yountville Ecopreserve, Tulukay Ck. @ Terrace Court, Murphy Ck. @ "Stone Bridge" on Coombsville Road, Carneros Ck. @ Withers, Salvadore channel @ Garfield Park, Milliken Ck. @ Hedgeside Avenue Brown Valley Ck. @ "Little Stone Bridge", Fagan Ck. @ Kelly Rd., Soda Ck. @ Silverado Trail Napa R. @ Trancas St., Sulphur Ck. @ Lower Bridge near Trailer Park , Bell Canyon Ck. @ Silverado, Dutch Henry Ck. @ Larkmead Lane Bridge, Napa R. @ 3rd St.,Napa R. @ Oak Knoll Ave., Redwood Ck. @ Redwood Road, Browns Valley Ck. @ Buhman Ave., Browns Valley Ck. @ Morningside Dr.,Murphy Ck. @ Shadybrook Ln., Tulukay Ck. @ Shurtleff Ave. (close to N11), Napa R. @ Heather Oaks Park, Napa R. @ Dunaweal Ln., Napa R. @ Larkmead Ln., Bell Canyon Ck. @ Crystal Springs Rd., Canon Ck. @322 Glass Mountain Rd., Napa R. @ Lodi Ln.,Napa R. @ Pope St. Saint Helena, Salvadore Channel @ 2280 Dry Ck. Rd., Salvadore Channel @ 121 near school, Shehey Creek @ N Kelly Road & Executive way (Sh-1), Napa River at Frogs Leap
Temporal Representation: Samples were collected during 2002, 2003, 2004, 2009, 2011, and 2012.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Some data were collected by Water Board staff following SWAMP Standard Operating Procedures and SWAMP Quality Assurance program Plan (QAPrP) (2008) and are SWAMP compliant, other data were collected by the San Francisco Estuary Institute.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 89762, Nutrients
Region 2     
Napa River, non-tidal
 
LOE ID: 96634
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 120
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: The data consisted of 120 individual instantaneous ammonia samples collected during 2002, 2003, 2004, 2009, 2011, and 2012 compared to the criterion continuous concentration adjusted for the pH and temperature of the sample. When pH and temperature values were missing, the average pH and temperature values were used to compute the evaluation guideline. None of these samples exceeded the chronic criterion.
Data Reference: Staff Report to Support Delisting of Napa River and Sonoma Creek for Nutrients
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: Water Quality Control Plan, San Francisco Bay Basin (RWQCB 2010): All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. There is no water quality objective for ammonia in the Water Quality Control Plan, San Francisco Bay Basin. Instead, the 2013 U.S. EPA criteria for ammonia was used as Temperature and pH-Dependent Values of the CCC (Chronic Criterion)for Fish Early Life Stages Present. For the pH and temperatures in this data set, the chronic criterion ranged from 0.1-2.8 mg/L and averaged 0.769 mg/L total ammonia.
Guideline Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Guideline Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Spatial Representation: Samples were collected from the following 38 stations on Napa River and its tributaries.Dry Ck. @ Railroad Bridge, Mill Ck. @ the old Bale Mill, Ritchey Ck. nr. Ranger Station, Napa Ck. @ Jefferson, Napa R. @ Calistoga Community Center, Napa R. @ Zinfandel Lane, Napa R. @ Tubbs Lane, Napa R. @ Yountville Ecopreserve, Tulukay Ck. @ Terrace Court, Murphy Ck. @ "Stone Bridge" on Coombsville Road, Carneros Ck. @ Withers, Salvadore channel @ Garfield Park, Milliken Ck. @ Hedgeside Avenue
Brown Valley Ck. @ "Little Stone Bridge", Fagan Ck. @ Kelly Rd., Soda Ck. @ Silverado Trail
Napa R. @ Trancas St., Sulphur Ck. @ Lower Bridge near Trailer Park , Bell Canyon Ck. @ Silverado
Dutch Henry Ck. @ Larkmead Lane Bridge, Napa R. @ 3rd St.,Napa R. @ Oak Knoll Ave.
Redwood Ck. @ Redwood Road, Browns Valley Ck. @ Buhman Ave., Browns Valley Ck. @ Morningside Dr.,Murphy Ck. @ Shadybrook Ln., Tulukay Ck. @ Shurtleff Ave. (close to N11)
Napa R. @ Heather Oaks Park, Napa R. @ Dunaweal Ln., Napa R. @ Larkmead Ln., Bell Canyon Ck. @ Crystal Springs Rd., Canon Ck. @322 Glass Mountain Rd., Napa R. @ Lodi Ln.,Napa R. @ Pope St. Saint Helena, Salvadore Channel @ 2280 Dry Ck. Rd., Salvadore Channel @ 121 near school
Shehey Creek @ N Kelly Road & Executive way (Sh-1), Napa River at Frogs Leap
Temporal Representation: Samples were collected during 2002, 2003, 2004, 2009, 2011, and 2012.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Some data were collected by Water Board staff following SWAMP Standard Operating Procedures and SWAMP Quality Assurance program Plan (QAPrP) (2008) and are SWAMP compliant, other data were collected by the San Francisco Estuary Institute.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 89762, Nutrients
Region 2     
Napa River, non-tidal
 
LOE ID: 94597
 
Pollutant: Nutrients
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: Placeholder reference pre-2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Unspecified
Objective/Criterion Reference: Placeholder reference pre-2006 303(d)
 
Evaluation Guideline: Unspecified
Guideline Reference: Placeholder reference pre-2006 303(d)
 
Spatial Representation: Unspecified
Temporal Representation: Unspecified
Environmental Conditions: Unspecified
QAPP Information: Unspecified
QAPP Information Reference(s):
 
 
DECISION ID
67894
Region 2     
Napa River, non-tidal
 
Pollutant: Pathogens
Final Listing Decision: Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2016)
Revision Status Original
Sources: Onsite Wastewater Systems (Septic Tanks)
TMDL Name: Napa River Pathogens
TMDL Project Code: 60
Date TMDL Approved by USEPA: 12/06/2007
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal on the CWA section 303(d) List under sections 2.2 and 3.1 of the Listing Policy. Under Section 3.1 of the Policy, a minimum of one line of evidence is needed to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

The original decision was for the entire Napa River. The Napa River was re-mapped into three segments, and the original listing and decision applies to this non-tidal segment of the Napa River.

4. A TMDL has been developed and approved by USEPA (December 6, 2007) and an approved implementation plan is expected to result in attainment of the standard. This provides a 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: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 67894, Pathogens
Region 2     
Napa River, non-tidal
 
LOE ID: 94600
 
Pollutant: Pathogens
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: Placeholder reference 2006 303(d)
 
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
67902
Region 2     
Napa River, non-tidal
 
Pollutant: Sedimentation/Siltation
Final Listing Decision: Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2016)
Revision Status Original
Sources: Agriculture | Road Construction
TMDL Name: Napa River Sediment
TMDL Project Code: 58
Date TMDL Approved by USEPA: 01/20/2011
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: The listing for sediment in Napa River originated from fine sediment impacts to spawning and rearing habitat as noted in the TMDL. The TMDL provides actions to reduce fine sediment input to the non-tidal portions of the main stems and all freshwater tributaries. When the Napa River was a single water body segment, the impairment and TMDL applied to entire main stem segment. Now that we have separated Napa River into tidal and non-tidal segments for the Integrated Repot purposes, we apply the listing for sediment to the non-tidal segments to be consistent with the impairment analyses and implementation actions required in the TMDLs.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 67902, Sedimentation/Siltation
Region 2     
Napa River, non-tidal
 
LOE ID: 94604
 
Pollutant: Sedimentation/Siltation
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: Placeholder reference pre-2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Unspecified
Objective/Criterion Reference: Placeholder reference pre-2006 303(d)
 
Evaluation Guideline: Unspecified
Guideline Reference: Placeholder reference pre-2006 303(d)
 
Spatial Representation: Unspecified
Temporal Representation: Unspecified
Environmental Conditions: Unspecified
QAPP Information: Unspecified
QAPP Information Reference(s):
 
 
DECISION ID
89913
Region 2     
Napa River, non-tidal
 
Pollutant: Mercury
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. One of eight samples exceed the guideline.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. One of eight samples exceed the guideline 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 sixteen samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 89913, Mercury
Region 2     
Napa River, non-tidal
 
LOE ID: 94602
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: One out of 2 samples exceeded. One filet composite sample of bluegill (1995) and two individual samples of brown bullhead (1995) and Sacramento pike minnow (1997) were collected. These values were averaged. The 1995 samples taken near Elm Street exceeded the guideline. The 1997 pike minnow taken near the J.F.K. boat ramp did not exceed (TSMP, 2002).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: San Francisco Bay RWQCB Basin Plan: Many pollutants can accumulate on particles, in sediment, or bioaccumulate in fish and other aquatic organisms. Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline: Mercury 0.3 ug/g (OEHHA Screening Value) (Brodberg and Pollock, 1999).
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Two stations were sampled: in Calistoga at Elm Street and 1/2 mile upstream from the J.F.K. Park boat ramp.
Temporal Representation: Samples were collected in 1995 and 1997.
Environmental Conditions:
QAPP Information: Toxic Substances Monitoring Program 1994-95 Data Report. Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program, 1996 to 2000. Department of Fish and Game.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 89913, Mercury
Region 2     
Napa River, non-tidal
 
LOE ID: 94598
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Six samples were collected with no exceedances (Napa Sanitation District, 2006).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Basin Plan Objective: 0.0250 ug/l
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Two stations were sampled: Napa River at Calistoga and Napa River at Napa.
Temporal Representation: Samples were collected in April, July and October of 2002.
Environmental Conditions:
QAPP Information: QA Info Missing
QAPP Information Reference(s):