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DECISION ID |
14109 |
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| Pollutant: |
Indicator Bacteria |
| 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: |
2021 |
| Impairment from Pollutant or Pollution: |
Pollutant |
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| Weight of Evidence: |
This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 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 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. Six of seven samples exceed the Basin Plan single single sample water quality objectives for indicator bacteria in fresh water and this exceeds 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 met. |
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| 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. |
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| SWRCB Board Decision / Staff Recommendation: |
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| USEPA Decision: |
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| LOE ID: |
26058 |
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| Pollutant: |
Indicator Bacteria |
| LOE Subgroup: |
Pollutant-Water |
| Matrix: |
Water |
| Fraction: |
None |
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| Beneficial Use: |
Water Contact Recreation |
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| Number of Samples: |
7 |
| Number of Exceedances: |
6 |
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| Data and Information Type: |
Other Agencies/Organizations provided monitoring data |
| Data Used to Assess Water Quality: |
Six of seven samples exceeded the Basin Plan single sample water quality objectives for indicator bacteria in fresh water and one of one sample exceeded the Basin Plan geometric mean water quality objectives. Water quality samples were taken and analyzed for indicator bacteria in accordance with the Municipal Separate Storm Sewer System (MS4) permit monitoring and testing parameters. |
| Data Reference: |
Monitoring Data (MS4 Data) for Tributaries of the San Gabriel River Watershed- CI 6948 for order no. 01-182 NPDES No. CAS004001 Municipal Storm Water and Urban Runoff Discharges within the County of Los Angeles, and the Incorporated Cities therein, Except the City of Long Beach |
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| Water Quality Objective/Criterion: |
The Basin Plan bacteria objectives state that to protect water contact recreation in fresh waters individual samples shall not exceed the following limits: fecal coliform density shall not exceed 400/100 ml; and E. coli density shall not exceed 235/100 ml. The bacteria objectives also establish that the geometric means of individual samples shall not exceed the following limits: the fecal coliform density shall not exceed 200/100 ml; and the E. coli density shall not exceed 126/100 ml, as a geometric mean. The bacteria objectives are found in Attachment A of Regional Board Resolution No. 2001-018. |
| Objective/Criterion Reference: |
Water Quality Control Plan Los Angeles Region R4 Basin Plan |
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Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009 |
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| Evaluation Guideline: |
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| Guideline Reference: |
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| Spatial Representation: |
The Los Angeles County Department of Public Works conducted sampling at monitoring station TS14 located at the Don Julian Road crossing with Puente Creek. |
| Temporal Representation: |
Grab samples were taken approximately six per year (four wet-weather events and two dry-weather events), from October 2006 through April 2007. |
| Environmental Conditions: |
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| QAPP Information: |
Data was collected in compliance with the sampling and monitoring procedures detailed in County of Los Angeles MS4 Permit (NPDES No. CAS004001) Monitoring and Reporting Program. |
| QAPP Information Reference(s): |
Monitoring and Reporting Program - CI 6948 for order no. 01-182
NPDES No. CAS004001 Municipal Storm Water and Urban Runoff Discharges within the County of Los Angeles, and the incorporated cities, except the City of
Long Beach
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DECISION ID |
14116 |
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| Pollutant: |
Selenium |
| 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: |
2021 |
| Impairment from Pollutant or Pollution: |
Pollutant |
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| Weight of Evidence: |
This pollutant is being considered for placement on the 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 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 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. Two of seven samples exceed the California Toxics Rule Criterion Continuous Concentration for Selenium in fresh water and this exceeds 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 met. |
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| 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. |
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| SWRCB Board Decision / Staff Recommendation: |
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| USEPA Decision: |
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Lines of Evidence (LOEs) for Decision ID 14116 |