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

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name: Mission Creek Lagoon (Santa Barbara County)
Water Body ID: CAT3153201220120412104249
Water Body Type: Wetland, Tidal
 
DECISION ID
82491
Region 3     
Mission Creek Lagoon (Santa Barbara County)
 
Pollutant: Toxicity
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 section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status and a water segment shall be placed on the section 303(d) List if the water segment exhibits statistically significant water or sediment toxicity using the binomial distribution as described in section 3.1 of the Listing Policy.

One line of evidence is available in the administrative record to assess this pollutant. One sample can have multiple toxicity test results (or endpoints) but will be counted only once. One sample is defined as being collected on the same day at the same location. Zero of the three samples exceed the water quality objective for aquatic life protection because they did not result in a significant toxic effect to the test organisms.

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 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. Zero of the three samples exceed the water quality objective for aquatic life protection and this does not exceed 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: 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 82491, Toxicity
Region 3     
Mission Creek Lagoon (Santa Barbara County)
 
LOE ID: 55184
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Sediment
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Three samples were collected to evaluate toxicity. None of the three samples exhibited significant toxicity. The toxicity tests for the samples included survival of Euhaustoriaus and Mytilus.
Data Reference: Data for toxicity in Mission Creek (Santa Barbara County), Mar 2007-Oct. 2009
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Central Coastal Basin
 
Evaluation Guideline: Toxicity is defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing. The t-test is used to determine if there is a statistically significant decrease in organism response in the sample as compared to the control.
Guideline Reference: Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. EPA-821-R-02-012
 
Spatial Representation: The samples were collected at site MC Lagoon.
Temporal Representation: The samples were collected from May 2007 to October 2009.
Environmental Conditions:
QAPP Information: The data was collected for the Preliminary Desisgn for the Mission Creek Lagoon and Laguna Channel Restoration Project, City of Santa Barbara 2011. There is no QAPP or QA documentation for this data.
QAPP Information Reference(s):