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

Supporting Information

Regional Board 8 - Santa Ana Region

Water Body Name: Lytle Creek, Middle Fork
Water Body ID: CAR8014100020110808233846
Water Body Type: River & Stream
 
DECISION ID
97912
Region 8     
Lytle Creek, Middle Fork
 
Pollutant: Benthic Community Effects
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: Benthic Community Effects is being considered for placement on the CWA section 303(d) List under sections 3.9 and 3.1 of the Listing Policy. Under section 3.9, an additional line of evidence associating Benthic Community Effects with a water or sediment concentration of pollutant(s) is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this indicator. None of the 3 benthic macroinvertebrate samples exceed (fall below) the California Streams Condition Index (CSCI) threshold for likely altered biological condition. The water segment does not have associated pollutant(s) samples that exceed water quality objectives.

Based on the readily available data and information, the weight of evidence provides sufficient justification for not placing Benthic Community Effects in this water 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. Pursuant to section 3.9 of the Listing Policy, the water segment does not exhibit significant degradation in biological populations and/or communities as compared to reference site(s) using the California Stream Condition Index. Additionally, this water body passed several screening criteria and was identified as a reference water body for the purposes of developing the CSCI. The State Water Board has redefined the Integrated Reporting categories in order to make them more reflective of actual water quality conditions in the State. This revision allows for the inclusion of minimally disturbed data reference sites that were identified in the development of the California Stream Condition Index (CSCI) tool into Category 1. Reference sites are the core of the State¿s statewide biological and habitat assessment program and set the benchmark for biological conditions expected when human activity in the landscape is absent or minimal. Unless there is any additional data showing that beneficial uses in a water body are not being supported, these reference water bodies along with any other bioassessment data sets showing a score of 0.92 or higher will be placed in Category 1 (all core beneficial uses are supported).
4. Pursuant to section 3.9 of the Listing Policy, the water segment does not have associated pollutant(s) samples that exceed water quality objectives.
5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not being met.

The California Stream Condition Index is a new scoring tool for bioassessment data that is applicable statewide, accounts for a much wider range of natural variability, and provides equivalent scoring thresholds in all regions of the state. The CSCI has been used in some assessments this reporting cycle and will be used in the future for water quality assessment purposes statewide over the regional indices of biologic integrity (IBIs). If CSCI scores have not been calculated for data and only IBI scores are available, IBI scores will still be used to interpret the data.
 
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: The California Stream Condition Index is a new scoring tool for bioassessment data that is applicable statewide, accounts for a much wider range of natural variability, and provides equivalent scoring thresholds in all regions of the state. The CSCI has been used in some assessments this reporting cycle and will be used in the future for water quality assessment purposes statewide over the regional indices of biologic integrity (IBIs). If CSCI scores have not been calculated for data and only IBI scores are available, IBI scores will still be used to interpret the data.
 
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 97912, Benthic Community Effects
Region 8     
Lytle Creek, Middle Fork
 
LOE ID: 81764
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: This site was assessed for benthic macroinvertebrates. The CSCI scores for this site are 1.1, 1.008789, and 1.277366. This site is above the 0.79 threshold and therefore meets the water quality objective for the aquatic life beneficial use.
Data Reference: Data for Various Pollutants in the Streams of Region 8, 2009.
  Complete data set for all CSCI reference sites for the entire State.
  Region 8 CSCI scores and data.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Inland surface water communities and populations, including vertebrate, invertebrate, and plant species, shall not be degraded as a result of the discharge of waste. Degradation is damage to an aquatic community or population with the result that balanced community no longer exists. The concentrations of toxic pollutants in the water column, sediments or biota shall not adversely affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan, Santa Ana River Basin
 
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: Sampling was done at the following stations: 801MLC069-Lytle Creek, SMCR8_057 and 801WE1020.
Temporal Representation: Sampling was done on 6/19/2002, 6/1/2007 and 5/18/2008.
Environmental Conditions:
QAPP Information: Samples were collected for the RWB8's Probabilistic Stream Survey CY2007 following SWAMP protocols and data were stored in the SWAMP database.
QAPP Information Reference(s):
 
 
DECISION ID
96243
Region 8     
Lytle Creek, Middle Fork
 
Pollutant: Nitrogen, Nitrate
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.

One (1) line of evidence is available in the administrative record to assess this pollutant. Zero (0) of the two (2) samples exceed the beneficial use criterion.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero (0) of the two (2) samples exceed the beneficial use criterion and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples are 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 96243, Nitrogen, Nitrate
Region 8     
Lytle Creek, Middle Fork
 
LOE ID: 81765
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: 0 of the 2 samples do not exceed the water quality objective for Nitrate (as N) at 10 mg/L. The data are reported as non-detects (NDs). These NDs are less than or equal to the water quality standard, the value will be considered as meeting the water quality standard, objective, criterion, or evaluation guideline.
Data Reference: Data for Various Pollutants from San Bernardino, 2004.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Santa Ana Region (1995): Waters designated for MUN shall not contain concentrations of chemical constituents in excess of the MCL specified in Title 22 of the California Code of Regulations. The Nitrate (as N) MCL is 10 mg/L.
Objective/Criterion Reference: Water Quality Control Plan, Santa Ana River Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at 801LCMFAS and 801WE1020 (Lytle Creek, Middle Fork).
Temporal Representation: Sample was collected on 6/29/2004.
Environmental Conditions:
QAPP Information: No quality assurance information was provided.
QAPP Information Reference(s):
 
 
DECISION ID
96301
Region 8     
Lytle Creek, Middle Fork
 
Pollutant: Nitrogen, Nitrite
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1, a single line of evidence is necessary to assess listing status.

One (1) line of evidence is available in the administrative record to assess this pollutant. Zero (0) of the two (2) samples exceed the beneficial use criterion.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero (0) of the two (2) samples exceed the beneficial use criterion and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples are 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 96301, Nitrogen, Nitrite
Region 8     
Lytle Creek, Middle Fork
 
LOE ID: 81757
 
Pollutant: Nitrogen, Nitrite
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: 0 of the 2 samples do not exceed the water quality objective for Nitrite (as N) at 1 mg/L. The data are reported as non-detects (NDs). These NDs are less than or equal to the water quality standard, the value will be considered as meeting the water quality standard, objective, criterion, or evaluation guideline.
Data Reference: Data for Various Pollutants from San Bernardino, 2004.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Santa Ana Region (1995): Waters designated for MUN shall not contain concentrations of chemical constituents in excess of the MCL specified in Title 22 of the California Code of Regulations. The Nitrite (as N) MCL is 1 mg/L.
Objective/Criterion Reference: Water Quality Control Plan, Santa Ana River Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at 801LCMFAS and 801WE1020 (Lytle Creek, Middle Fork).
Temporal Representation: Sample was collected on 6/29/2004.
Environmental Conditions:
QAPP Information: No quality assurance information was provided.
QAPP Information Reference(s):
 
 
DECISION ID
95546
Region 8     
Lytle Creek, Middle Fork
 
Pollutant: Total Nitrogen as N
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1, a single line of evidence is necessary to assess listing status.

A single line of evidence is available in the administrative record to assess this pollutant. Zero (0) of the two (2) samples exceed the water quality Objective.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero (0) of the two (2) samples exceed the water quality Objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples are 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 95546, Total Nitrogen as N
Region 8     
Lytle Creek, Middle Fork
 
LOE ID: 81758
 
Pollutant: Total Nitrogen as N
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: 0 of the 2 samples do not exceed the water quality objective for Total Nitrogen at 4 mg/L. The data are reported as non-detects (NDs). These NDs are less than or equal to the water quality standard, the value will be considered as meeting the water quality standard, objective, criterion, or evaluation guideline.
Data Reference: Data for Various Pollutants from San Bernardino, 2004.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Table 4-1 of the Santa Ana Basin Plan (1995) states that the water quality objective for Total Nitrogen for Lytle Creek, Middle Fork is 4 mg/L.
Objective/Criterion Reference: Water Quality Control Plan, Santa Ana River Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at 801LCMFAS and 801WE1020 (Lytle Creek, Middle Fork).
Temporal Representation: Sample was collected on 6/29/2004.
Environmental Conditions:
QAPP Information: No quality assurance information was provided.
QAPP Information Reference(s):