Final California 2010 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: Solstice Canyon Creek
Water Body ID: CAR4043200020050623113649
Water Body Type: River & Stream
 
DECISION ID
16622
Region 4     
Solstice Canyon Creek
 
Pollutant: Invasive Species
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Nonpoint Source | Point Source
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.10 of the Listing Policy. Under section 3.10, waters are listed when a declining trend in water quality is substantiated.

Two lines of evidence are available in the administrative record to assess this pollutant. One of 1 site showed an increase in density of mud snails over the three years of sampling (2006, 2007, 2008) and 1 out of 3 sites sampled showed medium or high densities of mud snail in 2008. (One site also exhibited a low density of mudsnails in 2008.)

At high numbers, mud snails can completely cover a stream bed and damage local stream ecosystems. The colonies outcompete native aquatic invertebrates that the watershed’s fish and amphibians rely on for food, disrupting the entire food web.

Benthic macroinvertebrates as measured by Southern California IBI (index of biological integrity) in Solstice Creek were good in 2005 indicating no impairment of the benthic community structure.

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 section 303(d) list in the Water Quality Limited Segments category.

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. Data was collected over a three years time frame and a baseline condition of zero abundance of the invasive species was used.
3. One of one sites showed an increase in density of mud snails over a three years of sampling and one of three sites sampled showed medium or high densities of mud snail in 2008.
4. Pursuant to section 3.11 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 be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
USEPA Action (if applicable): USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.
 
 
Line of Evidence (LOE) for Decision ID 16622, Invasive Species
Region 4     
Solstice Canyon Creek
 
LOE ID: 28704
 
Pollutant: Invasive Species
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Fish Migration | Fish Spawning | Wildlife Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: One of one sites showed an increase in density of mud snails over the three years of sampling (2006, 2007, 2008) and one of three sites sampled showed medium or high densities of mud snail in 2008.
Data Reference: New Zealand Mudsnail Surveys July 2006, July 2007 and October 2008 Santa Monica Mountains. Santa Monica Bay Restoration Commission / Santa Monica Baykeeper.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Basin Plan states that: "All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant or animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration or other appropriate methods as specified by the State or Regional Board.”
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: Presence of high densities and increasing densities. While quantitative and predictive research continues, due to its ability to attain extremely high densities, the impacts of the mudsnails on aquatic ecosystems where it occurs in the western U.S. are large and include: decreased densities of native macroinvertebrates and reduced food resources; decreased whole-stream algal production; poor food source in that mudsnails are much more difficult to digest, with their hard shells and operculum than are the thin-shelled, native pulmonate snails that do not have opercula or than soft-bodied, aquatic insect larvae.
Guideline Reference: The New Zealand Mudsnail Invades the Western United States. Aquatic Nuisance Species Digest Volume 4 No. 4.
 
Spatial Representation: Three sites were sampled in the following locations in Solstice Canyon Creek: NPS U.S. wood bridge; U.S. 2nd bridge; and1st bridge-PCH culvert.
Temporal Representation: The 1st bridge-PCH culvert site was sampled in in July of 2006, July of 2007 and October of 2008. The other two sites were sampled July of 2007 and October of 2008.
Environmental Conditions:
QAPP Information: Data was collected as detailed in the Santa Monica Bay Restoration Commission and Santa Monica Baykeeper New Zealand Mudsnail Surveys.
QAPP Information Reference(s): New Zealand Mudsnail Surveys July 2006, July 2007 and October 2008 Santa Monica Mountains. Santa Monica Bay Restoration Commission / Santa Monica Baykeeper.
 
Line of Evidence (LOE) for Decision ID 16622, Invasive Species
Region 4     
Solstice Canyon Creek
 
LOE ID: 30182
 
Pollutant: Invasive Species
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Fish Migration | Fish Spawning | Wildlife Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: One sampled in 2005 - IBI scores was calculated at 63 category “good”
Data Reference: Malibu Bioassessment Winter 2005
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Basin Plan states that: "All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant or animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration or other appropriate methods as specified by the State or Regional Board.”
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The IBI is a multi-metric assessment that employs biological metrics that respond to a habitat or water quality impairment. Each of the biological metrics measured at a site are converted to an IBI score then summed. These cumulative scores are then ranked as very good (80-100), good (60-79), fair (40-49), poor (20-39) and very poor (0-19) habitat conditions. Sites with scores below 39 are considered to have impaired conditions.
Guideline Reference: A Quantitative Tool for Assessing the Integrity of Southern Coastal California Streams. Appendix 7-B Environmental Management Vol. 35, No. 4, pp. 493-504.
 
Spatial Representation: One site in Solstice Creek was sampled, SC14
Temporal Representation: Sites were sampled in winter of 2005.
Environmental Conditions: Benthic macroinvertebrate populations and IBI scores may also be affected by a wide range of anthropogenic stressors.
QAPP Information: Data was collected in compliance with California Stream Bioassessment Procedure. Collection procedures were audited by California Department of Fish and Game in 2006.
QAPP Information Reference(s): California Stream Bioassessment Procedure (Protocol Brief for Biological and Physical/Habitat Assessment in Wadeable Streams) California Department of Fish and Game Water Pollution Control Laboratory Aquatic Bioassessment Laboratory Revision Date - December, 2003
  California Stream Bioassessment Procedure Biological and Physical Habitat Field Audit
 
 
DECISION ID
5427
Region 4     
Solstice Canyon Creek
 
Pollutant: Sulfates
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)(2006)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the 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. An insufficient total number of samples were taken and an insufficient number of samples exceed the MCL guideline for Sulfate.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

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. Four of four samples exceeded the MCL guideline. More data is needed to determine if the water quality standard is exceeded.
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: The decision has not changed.
 
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.
 
USEPA Action (if applicable):
 
 
Line of Evidence (LOE) for Decision ID 5427, Sulfates
Region 4     
Solstice Canyon Creek
 
LOE ID: 2270
 
Pollutant: Sulfates
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 4
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: There was a total of four samples with all four samples exceeding the objective (SWAMP, 2004).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: CCR- Title 22 Table 64449-B Secondary Maximum Contaminant Levels of 250 mg/l for Sulfate.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Two stations at Solstice Canyon Creek Middle: 34.03849 -118.75234 and at Solstice Canyon Creek Lower: 34.03194 -118.74287.
Temporal Representation: Samples were collected March 2003 through March 2004.
Environmental Conditions: Los Angeles County Coastal Streams: 404.32.
QAPP Information: SWAMP Quality Assurance Plan.
QAPP Information Reference(s):