|
DECISION ID |
8872 |
|
Pollutant: |
Toxicity |
Final Listing Decision: |
List on 303(d) list (TMDL required list) |
Last Listing Cycle's Final Listing Decision: |
New Decision |
Revision Status |
Revised |
Sources: |
Source Unknown |
Expected TMDL Completion Date: |
2019 |
Impairment from Pollutant or Pollution: |
Pollutant |
|
Weight of Evidence: |
This pollutant is being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under section 3.6 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.
Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for 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 6.1.3 of the
2. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
3. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
4. 67 of 150 samples exhibited significant toxicity to the Fathead Minnow, Ceriodaphnia, and Selanastrum and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy.
5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are met. |
|
RWQCB Board Decision / Staff 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. |
|
SWRCB Board Decision / Staff Recommendation: |
|
|
USEPA Decision: |
|
|
|
|
LOE ID: |
7834 |
|
Pollutant: |
Toxicity |
LOE Subgroup: |
Toxicity |
Matrix: |
Water |
Fraction: |
Total |
|
Beneficial Use: |
Estuarine Habitat |
Aquatic Life Use: |
Fish Migration | Fish Spawning | Preservation of Rare & Endangered Species | Wildlife Habitat |
|
Number of Samples: |
150 |
Number of Exceedances: |
67 |
|
Data and Information Type: |
Fixed station physical/chemical (conventional plus toxic pollutants) |
Data Used to Assess Water Quality: |
67 of 150 samples exhibited significant toxicity to the Fathead Minnow, Ceriodaphnia, and Selanastrum. Semi-annual ambient water quality samples for toxicity were taken in compliance with the Ventura Water Reclamation Facility NDPES permit monitoring requirements. |
Data Reference: |
NPDES receiving water monitoring reports for the City of San Buenaventura Ventura Water Reclamation Facility (NPDES No. CA0053651). |
|
Water Quality Objective/Criterion: |
The Basin Plan states at there shall be no acute or chronic toxicity in ambient waters outside mixing zones. |
Objective/Criterion Reference: |
Water Quality Control Plan Los Angeles Region R4 Basin Plan |
|
Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009 |
|
Evaluation Guideline: |
Toxicity was defined as a reduction of the NOEC below 100% and was considered significant if the effect on the sample exposure was greater than 25%. Chronic toxicity is further expressed as toxic units (TUc), where TUc = 100/NOEC
The No Observable Effect Concentration (NOEC) is expressed as the maximum percent of receiving water that causes no observable effect on a test organism, as determined by the result of a critical life stage toxicity test. The NOEC is defined, in (USEPA, 2002) as the The lowest concentration of toxicant to which organisms are exposed in a life-cycle or partial life-cycle (short-term) test, which causes adverse effects on the test organisms (i.e., where the values for the observed responses are statistically significantly different from the controls). |
Guideline Reference: |
U.S. EPA, 2002. Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition, October 2002.
|
|
FINAL Calleguas Creek Watershed Toxicity, Chlorpyrifos and Diazinon TMDL Technical Report. 2005. Submitted to Los Angeles Regional Water Quality Control Board. Prepared by Larry Walker Associates on behalf of the Calleguas Creek Watershed Management Plan. June 21, 2005. |
|
Spatial Representation: |
The listed monitoring stations for this water body pollutant combination include: R1 located at the south shoreline, R3 located at the west shoreline, and L5 located at the northwest shoreline. |
Temporal Representation: |
Grab samples were taken and analyzed on semi-annual basis from January 2002 to February 2007. |
Environmental Conditions: |
|
QAPP Information: |
Data was collected in compliance with the sampling and monitoring procedures detailed in NPDES Permit No. CA0053651 Monitoring and Reporting Program. |
QAPP Information Reference(s): |
Ventura Water Reclamation Facility Monitoring and reporting program for NPDES No. CA0053651
|