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

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name: Fall Creek
Water Body ID: CAR3041202219990225133326
Water Body Type: River & Stream
 
DECISION ID
132067
Region 3     
Fall Creek
 
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/are available in the administrative record to assess this indicator. Zero of one benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold. However, a minimum of two benthic-macroinvertebrate samples are needed to assess listing status.

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. The available information is insufficient to determine whether the waterbody/pollutant combination should 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: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.
 
 
Line of Evidence (LOE) for Decision ID 132067, Benthic Community Effects
Region 3     
Fall Creek
 
LOE ID: 233361
 
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 304FALHCP to determine beneficial use support and the results are as follows: 0 of 1 samples exceeded the threshold. CSCI scores were from 1.01121 to 1.01121.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2020 Integrated Report for Region 3.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Region 3 Basin Plan.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal 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: Samples were collected from station 304FALHCP.
Temporal Representation: Samples were collected from 5/21/2009 to 5/21/2009.
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
 
 
DECISION ID
90466
Region 3     
Fall Creek
 
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: Erosion/Siltation | Habitat Modification | Nonpoint Source | Road Construction
TMDL Name: San Lorenzo River Sediment
TMDL Project Code: 243
Date TMDL Approved by USEPA: 02/19/2004
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 4.9 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. The initial decision to place this water body segment-pollutant combination on the 303(d) list was made prior to 2006 and associated data and documentation are not held in an assessment database. As a result, there are no data associated with the LOE that is a placeholder for the original decision to add this water body segment-pollutant combination to the List. However, recent physical habitat and benthic invertebrate community data have been collected and are summarized in one LOE. Both of the samples more than 40 percent cover of deposited fine and sand sized sediment on the streambed. However, there are an insufficient number of samples to determine beneficial use support.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Both of the samples more than 40 percent cover of deposited fine and sand sized sediment on the streambed and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board 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 90466, Sedimentation/Siltation
Region 3     
Fall Creek
 
LOE ID: 3947
 
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):
 
Line of Evidence (LOE) for Decision ID 90466, Sedimentation/Siltation
Region 3     
Fall Creek
 
LOE ID: 95250
 
Pollutant: Sediment
LOE Subgroup: Population/Community Degradation
Matrix: Not Specified
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 2
 
Data and Information Type: BIOLOGICAL MONITORING
Data Used to Assess Water Quality: Water Board staff evaluated sediment grain size and EPT taxa data that was collected following the SWAMP physical habitat and benthic invertebrate protocol from Fall Creek. At two of the two stations, deposited fine and sand (FS) sediments on the stream bed were greater than 40%. However, neither sample had less than 12 EPT taxa (EPT richness) present at these locations.
Sediment percent cover measures 43 percent and 41 percent at the two stations.
Data Reference: Three papers summarizing numeric TMDL targets for benthic invertebrates and sediment indicators in the San Lorenzo River Watershed
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Central Coast Water Quality Control Plan (Basin Plan) general water quality objective. Waters shall not contain settable material in concentrations that result in deposition of material that cause nuisance or adversely affects beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Loss of benthic invertebrate species diversity and altered community composition (based on the number of mayfly, stonefly and caddisfly taxa or EPT taxa richness) occurs when deposited fine and sand (FS) sediments on the stream bed exceeds 40% relative to Central Coast reference stream species composition and diversity (Herbst, D.B., et al, 2014 and Herbst, D.B., et al, 2011).
Guideline Reference: Three papers summarizing numeric TMDL targets for benthic invertebrates and sediment indicators in the San Lorenzo River Watershed
 
Spatial Representation: One monitoring location: Cowell SP (2008 and 2009).
Temporal Representation: Samples were collected in the spring - early season of 2007, 2008 and 2009
Environmental Conditions: None
QAPP Information: SWAMP protocols were followed for sample collection. SWAMP QAPP was followed.
QAPP Information Reference(s):
 
 
DECISION ID
86083
Region 3     
Fall Creek
 
Pollutant: Temperature, water
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 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the evaluation guideline (Moyle, 1976) used to interpret the water quality objective for water temperature.

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. The single sample did not exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 86083, Temperature, water
Region 3     
Fall Creek
 
LOE ID: 54132
 
Pollutant: Temperature, water
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Water temperature data submitted by the Lompico Watershed Conservancy from the summer months of 2005 showed that the maximum weekly maximum temperature (MWMT) never exceeded 16 degrees Celsius. The MWMT is an average for the year and therefore, for the purpose of this assessment is counted as a single sample and exceedance. These data were compiled by Donald Alley (fisheries biologist).
Data Reference: Data for temperature in San Lorenzo Creek (Monterey County) and other water bodies, May 2005-Aug. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (General Objective in Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)
 
Evaluation Guideline: Per 'U.S. EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards' (USEPA 2003), the U.S. EPA recommends a criterion for the protection of moderate to high density summertime salmon and trout juvenile rearing (i.e., core juvenile rearing) of a maximum weekly maximum temperature (MWMT) of 16 degrees C. The MWMT is also known as the maximum 7-day average of daily maximums (7DADM). The 16 degrees C MWMT criterion is recommended to (1) safely protect juvenile salmon and trout from lethal temperatures; (2) provide upper optimal conditions for juvenile growth under limited food during the period of summer maximum temperatures and optimal temperatures for other times of the growth season; (3) avoid temperatures where juvenile salmon and trout are at a competitive disadvantage with other fish; (4) protect against temperature induced elevated disease rates; and (5) provide temperatures that studies show juvenile salmon and trout prefer and are found in high densities. Both the CDFG and NOAA strongly support the use of the USEPA temperature guidance for the purposes of water quality assessment in California. These criteria have been adopted by both Oregon and Washington state and used for 303(d) Listing and TMDL development by the North Coast Region Water Quality Control Board. Its use in other geographic settings is appropriate as it has been recognized that salmonid stocks do not tend to vary much in their life history thermal needs, regardless of their geographic location. There is not enough significant genetic variation among stocks or among species of salmonids to warrant geographically specific water temperature standards.
Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency Region 10 Office of Water, Seattle, WA.
 
Spatial Representation: Data collected at site 15: Below bridge for trail leading from Empire Grade parking lot.
Temporal Representation: Data collected daily from 6/11/2005-10/12/2005.
Environmental Conditions:
QAPP Information: There was no QAPP submitted with this data, but detailed letters outlining QA/QC procedures were provided by the city of Santa Cruz and Donald Alley.
QAPP Information Reference(s):