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

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name: TID Lower Stevinson Canal (Merced County)
Water Body ID: CAR5355000020191220041664
Water Body Type: River & Stream
 
DECISION ID
120872
Region 5     
TID Lower Stevinson Canal (Merced County)
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: A Source Unknown
Expected TMDL Completion Date: 2035
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant. 3 of the 7 samples exceed the criteria/objective for the Municipal and Domestic Supply beneficial use.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination 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. 3 of the 7 samples exceed the criteria/objective for the Municipal and Domestic Supply beneficial use, and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
 
Line of Evidence (LOE) for Decision ID 120872, Nitrate/Nitrite (Nitrite + Nitrate as N)
Region 5     
TID Lower Stevinson Canal (Merced County)
 
LOE ID: 192025
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 7
Number of Exceedances: 3
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed East San Joaquin Water Quality Coalition data for TID Lower Stevinson Canal (Merced County) to determine beneficial use support and results are as follows: 3 of 7 samples exceeded the water quality threshold for Nitrate + Nitrite as N.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Maximum Contaminant Level for nitrate + nitrite (as N) incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 10 mg/L (California Code of Regulations, Title 22).
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:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (535LSAFHR)
Temporal Representation: The samples were collected between the dates of 2016-10-18 and 2017-07-11
Environmental Conditions:
QAPP Information: Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.
QAPP Information Reference(s): Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition
 
 
DECISION ID
131250
Region 5     
TID Lower Stevinson Canal (Merced County)
 
Pollutant: Specific Conductivity
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: A Source Unknown
Expected TMDL Completion Date: 2033
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

One line of evidence are available in the administrative record to assess this pollutant. 10 of the 27 samples exceed the OBJECTIVE for MUN.

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. 10 of the 27 samples exceed the OBJECTIVE for MUN and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
 
Line of Evidence (LOE) for Decision ID 131250, Specific Conductivity
Region 5     
TID Lower Stevinson Canal (Merced County)
 
LOE ID: 230019
 
Pollutant: Specific Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 27
Number of Exceedances: 10
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed East San Joaquin Water Quality Coalition data for TID Lower Stevinson Canal (Merced County) to determine beneficial use support and results are as follows: 10 of 27 samples exceeded the water quality threshold for SpecificConductivity.
Data Reference: Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Secondary MCL that is incorporated by reference in the Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin for specific conductance is 900 uS/cm.
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:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (535LSAFHR)
Temporal Representation: The samples were collected between the dates of 2013-10-15 and 2016-10-29
Environmental Conditions:
QAPP Information: Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.
QAPP Information Reference(s): Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition