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

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name: Niagara Creek (Tuolumne County)
Water Body ID: CAR5343001020150624053105
Water Body Type: River & Stream
 
DECISION ID
126992
Region 5     
Niagara Creek (Tuolumne County)
 
Pollutant: Indicator Bacteria
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Sources: A Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: The State Water Board’s Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (the “ISWEBE Plan”) contains two bacteria water quality objectives applicable to the REC-1 beneficial use, which were adopted on August 7, 2018. Because the salinity level of this waterbody is equal to or less than 1 part per thousand 95 percent or more of the time, the E. coli bacteria objective applies Therefore, this waterbody is being considered for removal from the CWA section 303(d) List under section 4.3 of the Listing Policy, as applicable, using the E. Coli objective.

In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. Indicator bacteria (total coliform, fecal coliform, E. coli, enterococci) populations may fluctuate substantially on a daily, seasonal, or yearly basis. Lacking constant inputs, they do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of indicator bacteria in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Additionally, water quality conditions in waterbodies may change as a result of management actions that have been implemented to address bacteria. Unrepresentative data may result in incorrectly placing or not placing a water body segment on the list, which could result in the unnecessary expenditure of public resources or missing a human health problem.

Seventeen lines of evidence are available based on the new E. coli objective. There are an insufficient number of samples available to apply the binomial distribution table in section 4.2 of the Listing Policy to determine beneficial use support.

No fecal coliform data are used in this assessment because the fecal coliform water quality objective was superseded and is no longer used as the basis of any 303(d) List decision for water contact recreation.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient 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. There are insufficient samples available to determine listing status using the newly adopted E. coli objective.
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 194521
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Niagara Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 6 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): NC_EMR_U
Temporal Representation: The samples were collected between the days of 2012-06-13 and 2015-08-05 .
Environmental Conditions:
QAPP Information: Central Sierra Environmental Resource Center. 2010. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2016. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center (CSERC). 2017. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2018. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest.
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 194530
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Niagara Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 5 samples exceeded the geomean water quality threshold for E. coli. This is a six week rolling geomean that is calculated weekly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a six-week rolling GEOMETRIC MEAN (GM) of Escherichia coli (E. coli) not to exceed 100 colony forming units per 100 milliliters (cfu/100 mL) (calculated weekly).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): NC_BM_LII
Temporal Representation: The samples were collected between the days of 2017-07-06 and 2017-10-26 .
Environmental Conditions:
QAPP Information: Central Sierra Environmental Resource Center. 2010. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2016. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center (CSERC). 2017. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2018. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest.
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 194482
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Niagara Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 2 samples exceeded the geomean water quality threshold for E. coli. This is a six week rolling geomean that is calculated weekly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a six-week rolling GEOMETRIC MEAN (GM) of Escherichia coli (E. coli) not to exceed 100 colony forming units per 100 milliliters (cfu/100 mL) (calculated weekly).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): NC_EMR_U
Temporal Representation: The samples were collected between the days of 2012-06-13 and 2015-08-05 .
Environmental Conditions:
QAPP Information: Central Sierra Environmental Resource Center. 2010. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2016. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center (CSERC). 2017. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2018. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest.
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 194797
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Niagara Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the geomean water quality threshold for E. coli. This is a six week rolling geomean that is calculated weekly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a six-week rolling GEOMETRIC MEAN (GM) of Escherichia coli (E. coli) not to exceed 100 colony forming units per 100 milliliters (cfu/100 mL) (calculated weekly).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): EM7-UCD-Tate
Temporal Representation: The samples were collected between the days of 2016-07-13 and 2016-09-14 .
Environmental Conditions:
QAPP Information: Kenneth W. Tate, Ph.D., CRM. 2011. UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)., Kenneth W. Tate, Ph.D., CRM. 2016. UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP)
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 194508
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 4
Number of Exceedances: 1
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Niagara Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 1 of the 4 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): NC_BM_LII
Temporal Representation: The samples were collected between the days of 2017-07-06 and 2017-10-26 .
Environmental Conditions:
QAPP Information: Central Sierra Environmental Resource Center. 2010. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2016. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center (CSERC). 2017. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2018. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest.
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 194751
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Niagara Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 1 of the 2 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): EM5-UCD-Tate
Temporal Representation: The samples were collected between the days of 2016-07-13 and 2016-08-03 .
Environmental Conditions:
QAPP Information: Kenneth W. Tate, Ph.D., CRM. 2011. UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)., Kenneth W. Tate, Ph.D., CRM. 2016. UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP)
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 96074
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 14
Number of Exceedances: 5
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Five of 14 samples exceeded the SSM evaluation guideline for E. coli.
Data Reference: Bacteria Contamination, Violations, and Field Data for Stanislaus, 2009-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The single sample maxima (SSM) allowable density for E. coli in freshwater is 235 MPN/100mL.
Guideline Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Spatial Representation: Samples were collected below Barn Meadow from a tributary stream to Niagara Creek (which is within the Long Valley/Eagle Meadow Range Allotment) at three sample locations. Due to a lack of flow, the original Barn Meadows site was used only until July 9, 2009. A new site (BM1) was selected downstream of the original site on July 9, 2009, and an additional site was added (BM2) July 16, 2009. The BM1 and BM2 samples were collected from two separate tributaries to Niagara Creek.
Temporal Representation: Samples were collected from June to August in 2009.
Environmental Conditions: Grazing was first observed in the immediate Barn Meadow area on July 9, 2009. Cattle grazing continued in this allotment until October 15, 2009. The elevation range for these sample locations is 7,362 ft - 7,697 ft.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in ¿Surface Water Ambient Monitoring Project in the Santislaus National Forest - Quality Assurance Project Plan ¿ (Myers, 2010).
QAPP Information Reference(s): Quality Assurance Project Plan for Stanislaus National Forest by Central Sierra Environmental Resource Center.
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 194860
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Niagara Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 1 of the 3 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): EM7-UCD-Tate
Temporal Representation: The samples were collected between the days of 2016-07-13 and 2016-09-14 .
Environmental Conditions:
QAPP Information: Kenneth W. Tate, Ph.D., CRM. 2011. UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)., Kenneth W. Tate, Ph.D., CRM. 2016. UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP)
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 194744
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Niagara Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 3 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): EM6-UCD-Tate
Temporal Representation: The samples were collected between the days of 2016-07-13 and 2016-09-20 .
Environmental Conditions:
QAPP Information: Kenneth W. Tate, Ph.D., CRM. 2011. UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)., Kenneth W. Tate, Ph.D., CRM. 2016. UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP)
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 194749
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Niagara Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the geomean water quality threshold for E. coli. This is a six week rolling geomean that is calculated weekly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a six-week rolling GEOMETRIC MEAN (GM) of Escherichia coli (E. coli) not to exceed 100 colony forming units per 100 milliliters (cfu/100 mL) (calculated weekly).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): EM6-UCD-Tate
Temporal Representation: The samples were collected between the days of 2016-07-13 and 2016-09-20 .
Environmental Conditions:
QAPP Information: Kenneth W. Tate, Ph.D., CRM. 2011. UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)., Kenneth W. Tate, Ph.D., CRM. 2016. UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP)
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 194736
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Niagara Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): EM4-UCD-Tate
Temporal Representation: The samples were collected between the days of 2016-07-13 and 2016-07-27 .
Environmental Conditions:
QAPP Information: Kenneth W. Tate, Ph.D., CRM. 2011. UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)., Kenneth W. Tate, Ph.D., CRM. 2016. UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP)
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 194542
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Niagara Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 3 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): NC_BM_U
Temporal Representation: The samples were collected between the days of 2016-06-30 and 2016-08-09 .
Environmental Conditions:
QAPP Information: Central Sierra Environmental Resource Center. 2010. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2016. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center (CSERC). 2017. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2018. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest.
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 194420
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Niagara Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 3 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): NC_EMR_L
Temporal Representation: The samples were collected between the days of 2014-06-10 and 2014-08-05 .
Environmental Conditions:
QAPP Information: Central Sierra Environmental Resource Center. 2010. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2016. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center (CSERC). 2017. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2018. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest.
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 77249
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 14
Number of Exceedances: 3
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Three of 14 samples exceeded the STV evaluation guideline for E. coli.
Data Reference: Bacteria Contamination, Violations, and Field Data for Stanislaus, 2009-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The statistical threshold value (STV) allowable density for E. coli in freshwater is 320 cfu/100mL. (USEPA. 2012 Recreational Water Quality Criteria for Bacteria)
Guideline Reference: 2012 USEPA Recreational Water Quality Criteria - Bacteria
 
Spatial Representation: Samples were collected below Barn Meadow from a tributary stream to Niagara Creek (which is within the Long Valley/Eagle Meadow Range Allotment) at three sample locations. Due to a lack of flow, the original Barn Meadows site was used only until July 9, 2009. A new site (BM1) was selected downstream of the original site on July 9, 2009, and an additional site was added (BM2) July 16, 2009. The BM1 and BM2 samples were collected from two separate tributaries to Niagara Creek.
Temporal Representation: Samples were collected from June to August in 2009.
Environmental Conditions: Grazing was first observed in the immediate Barn Meadow area on July 9, 2009. Cattle grazing continued in this allotment until October 15, 2009. The elevation range for these sample locations is 7,362 ft - 7,697 ft.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in ¿Surface Water Ambient Monitoring Project in the Santislaus National Forest - Quality Assurance Project Plan ¿ (Myers, 2010).
QAPP Information Reference(s): Quality Assurance Project Plan for Stanislaus National Forest by Central Sierra Environmental Resource Center.
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 194533
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Niagara Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 2 samples exceeded the geomean water quality threshold for E. coli. This is a six week rolling geomean that is calculated weekly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a six-week rolling GEOMETRIC MEAN (GM) of Escherichia coli (E. coli) not to exceed 100 colony forming units per 100 milliliters (cfu/100 mL) (calculated weekly).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): NC_BM_U
Temporal Representation: The samples were collected between the days of 2016-06-30 and 2016-08-09 .
Environmental Conditions:
QAPP Information: Central Sierra Environmental Resource Center. 2010. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2016. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center (CSERC). 2017. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2018. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest.
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 77243
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 11
Number of Exceedances: 5
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Five of the 11 calculated geometric means exceeded the evaluation guideline for E. coli
Data Reference: Bacteria Contamination, Violations, and Field Data for Stanislaus, 2009-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The geometric mean of E. coli densities should not exceed 100cfu/100 ml (USEPA 2012).
Guideline Reference: 2012 USEPA Recreational Water Quality Criteria - Bacteria
 
Spatial Representation: Samples were collected below Barn Meadow from a tributary stream to Niagara Creek (which is within the Long Valley/Eagle Meadow Range Allotment) at three sample locations. Due to a lack in flow, the original Barn Meadows site (BM) was sampled before July 9, 2009. A new site (BM1) was selected downstream of the original site on July 9, 2009, and an additional site was added (BM2) July 16, 2009.
Temporal Representation: Samples were collected from June to August in 2009.
Environmental Conditions: Samples were collected after livestock arrival at both BM1 and BM2. Grazing was first observed in the immediate Barn Meadow area on July 9, 2009. Cattle grazing continued in this allotment until October 15, 2009. The elevation range for these sample locations is 7,362 ft - 7,697 ft.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in ¿Surface Water Ambient Monitoring Project in the Santislaus National Forest - Quality Assurance Project Plan ¿ (Myers, 2010).
QAPP Information Reference(s): Quality Assurance Project Plan for Stanislaus National Forest by Central Sierra Environmental Resource Center.
 
Line of Evidence (LOE) for Decision ID 126992, Indicator Bacteria
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 96075
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 11
Number of Exceedances: 4
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Four of the 11 calculated geometric means exceeded the evaluation guideline for E. coli
Data Reference: Bacteria Contamination, Violations, and Field Data for Stanislaus, 2009-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The geometric mean of E. coli densities should not exceed 126 MPN/100 ml.
Guideline Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Spatial Representation: Samples were collected below Barn Meadow from a tributary stream to Niagara Creek (which is within the Long Valley/Eagle Meadow Range Allotment) at three sample locations. Due to a lack in flow, the original Barn Meadows site (BM) was sampled before July 9, 2009. A new site (BM1) was selected downstream of the original site on July 9, 2009, and an additional site was added (BM2) July 16, 2009.
Temporal Representation: Samples were collected from June to August in 2009.
Environmental Conditions: Samples were collected after livestock arrival at both BM1 and BM2. Grazing was first observed in the immediate Barn Meadow area on July 9, 2009. Cattle grazing continued in this allotment until October 15, 2009. The elevation range for these sample locations is 7,362 ft - 7,697 ft.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in ¿Surface Water Ambient Monitoring Project in the Santislaus National Forest - Quality Assurance Project Plan ¿ (Myers, 2010).
QAPP Information Reference(s): Quality Assurance Project Plan for Stanislaus National Forest by Central Sierra Environmental Resource Center.
 
 
DECISION ID
131673
Region 5     
Niagara Creek (Tuolumne County)
 
Pollutant: Benthic Community Effects
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Benthic Community Effects are being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, additional lines of evidence (LOEs) associating the Benthic Community Effects decision with a water or sediment concentration of pollutants other than benthic-macroinvertebrate bioassessment or habitat assessment LOEs are necessary to place a water body on the 303(d) List for Benthic Community Effects.

One line of evidence evaluating benthic-macroinvertebrate bioassessment data is available in the administrative record to assess this indicator. Zero of one benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold. These data indicate that the waterbody is likely unimpaired for Benthic Community Effects and therefore no other pollutant LOEs need be associated with this decision at this time.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing Benthic Community Effects in this waterbody segment on the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of one benthic-macroinvertebrate bioassessment samples had CSCI scores below 0.79. Therefore, this water body is not exceeding the water quality threshold for the protection of the COLD beneficial use. The available information indicates that the waterbody/pollutant combination should not be placed on the 303(d) List of impaired waters at this time.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 131673, Benthic Community Effects
Region 5     
Niagara Creek (Tuolumne County)
 
LOE ID: 232120
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 534PS0070 to determine beneficial use support and the results are as follows: 0 of 1 samples exceeded the threshold. CSCI scores were from 1.100461485 to 1.100461485.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2020 Integrated Report for Region 5.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. Region 5 Basin Plan
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins; Fifth Edition. Revised May 2018 (with approved amendments)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 534PS0070.
Temporal Representation: Samples were collected from 8/30/2010 to 8/30/2010.
Environmental Conditions:
QAPP Information: Data collected following SWAMP QA protocols.
QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program