| Water Body Name: | Arroyo Seco Reach 1 (LA River to West Holly Ave.) |
| Water Body ID: | CAR4051501019990202132906 |
| Water Body Type: | River & Stream |
DECISION ID |
18203 |
Region 4 |
Arroyo Seco Reach 1 (LA River to West Holly Ave.) |
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| Pollutant: | Excess Algal Growth |
| Final Listing Decision: | Delist from 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | Delist from 303(d) list (TMDL required list)(2010) |
| Revision Status | Original |
| Reason for Delisting: | Flaws in original listing |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | Region 4 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle.
This condition is being considered for listing under section 2.2 of the Listing Policy. Under this section of the Policy, a minimum of two lines of evidence is needed to assess listing status. The Los Angeles River Nitrogen TMDL was approved by RWQCB on August 19, 2003 and subsequently approved by USEPA on March 18, 2004. This TMDL will address this water body condition. Qualitative information on excess algal growth alone is not sufficient to support placement on the section 303(d) list (Listing Policy section 3.7). 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 in the Water Quality Limited Segments Being Addressed portion of the section 303(d) list. |
| Regional Board Decision Recommendation: | Region 4 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle. |
| State Board Staff Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | Region 4 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle.
After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board. |
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| LOE ID: | 2486 | ||||
| Pollutant: | Excess Algal Growth | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Not Recorded | ||||
| Beneficial Use: | Warm 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 2006 303(d) | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | |||||
| Objective/Criterion Reference: | |||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | |||||
| Temporal Representation: | |||||
| Environmental Conditions: | |||||
| QAPP Information: | QA Info Missing | ||||
| QAPP Information Reference(s): | |||||
DECISION ID |
30324 |
Region 4 |
Arroyo Seco Reach 1 (LA River to West Holly Ave.) |
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| Pollutant: | Benthic-Macroinvertebrate Bioassessments |
| Final Listing Decision: | List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2010) |
| Revision Status | Original |
| Sources: | Source Unknown |
| Expected TMDL Completion Date: | 2021 |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | Region 3 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle. |
| Regional Board Decision Recommendation: | Region 4 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle.
After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be added to the section 303(d) list because applicable water quality standards are not being attained. |
| State Board Staff Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | Region 4 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle.
After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board. |
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| LOE ID: | 30223 | ||||
| Pollutant: | Benthic-Macroinvertebrate Bioassessments | ||||
| LOE Subgroup: | Population/Community Degradation | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Non-Contact Recreation | ||||
| Number of Samples: | 0 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | Benthic macroinvertebrate surveys | ||||
| Data Used to Assess Water Quality: | The IBI scores at this site ranked in the very poor range (11 in 2003 and 9 in 2004). | ||||
| Data Reference: | Los Angeles County 1994-2005 Integrated Receiving Water Impacts Report. Section 5, Los Angeles River Watershed Management Area, pp5.1 - 5.40 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Los Angeles RWQCB Basin Plan Objectives for Toxicity which states 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, analyses of species diversity, population density, growth anomalies, bioassays of appropriate duration or other appropraite methods as specified by the State or Regional Board. | ||||
| 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 Basin Plan 1997-2009 | |||||
| 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 according to very good (80-56), good (41-55), fair (27-40), poor (14-26) and very poor (0-13) habitat conditions. Sites with scores below 26 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. | ||||
| Los Angeles County 1994-2005 Integrated Receiving Water Impacts Report. Section 3, Methods, pp3.1 - 3.28 | |||||
| Los Angeles County 1994-2005 Integrated Receiving Water Impacts Report. Section 5, Los Angeles River Watershed Management Area, pp5.1 - 5.40 | |||||
| Spatial Representation: | One site in the Arroyo Seco was sampled, Arroyo Seco and I-134, at N 34º 08.686 W 118º 09.987 | ||||
| Temporal Representation: | Sites were sampled in October of 2003 and October of 2004. | ||||
| 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. | ||||
| 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 | ||||
| Los Angeles County 1994-2005 Integrated Receiving Water Impacts Report. Section 3, Methods, pp3.1 - 3.28 | |||||
DECISION ID |
20947 |
Region 4 |
Arroyo Seco Reach 1 (LA River to West Holly Ave.) |
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| Pollutant: | Coliform Bacteria |
| Final Listing Decision: | List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2010) |
| Revision Status | Original |
| Sources: | Source Unknown |
| Expected TMDL Completion Date: | 2009 |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | Region 4 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle.
303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed. |
| Regional Board Decision Recommendation: | Region 4 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle. |
| State Board Staff Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | Region 4 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle.
After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board. |
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| LOE ID: | 4027 | ||||
| Pollutant: | Coliform Bacteria | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Not Recorded | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| 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): | |||||
DECISION ID |
28322 |
Region 4 |
Arroyo Seco Reach 1 (LA River to West Holly Ave.) |
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| Pollutant: | Trash |
| Final Listing Decision: | List on 303(d) list (being addressed by USEPA approved TMDL) |
| Last Listing Cycle's Final Listing Decision: | List on 303(d) list (being addressed by USEPA approved TMDL)(2010) |
| Revision Status | Original |
| Sources: | Nonpoint Source | Surface Runoff | Urban Runoff/Storm Sewers |
| TMDL Name: | Los Angeles River Trash (12) |
| TMDL Project Code: | 365 |
| Date TMDL Approved by USEPA: | 07/24/2008 |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | Region 4 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle.
This pollutant is being considered for removal on the section 303(d) list under sections 2.2 of the Listing Policy. Under 2.2 of the Policy, a minimum of one line of evidence is needed to assess listing status. Two lines of evidence are 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 against removing this water segment-pollutant combination from the section 303(d) list. There is sufficient justification to place it in the Being Addressed portion of the 303(d) list because a TMDL has been completed and adopted by the Los Angeles RWQCB and approved by USEPA, and is expected to result in attainment of the standard. |
| Regional Board Decision Recommendation: | Region 4 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle.
After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the Water Quality Limited Segments Being Addressed category of the section 303(d) list because a TMDL has been approved by USEPA, and applicable water quality standards are exceeded and a pollutant contributes to or causes the problem. |
| State Board Staff Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | Region 4 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle.
After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board. |
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| LOE ID: | 28085 | ||||
| Pollutant: | Trash | ||||
| LOE Subgroup: | Narrative Description Data | ||||
| Matrix: | Not Specified | ||||
| Fraction: | None | ||||
| Beneficial Use: | Non-Contact Recreation | ||||
| Number of Samples: | 0 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | Not Specified | ||||
| Data Used to Assess Water Quality: | A TMDL has been approved for this water segment-pollutant combination. The Trash TMDL for the Los Angeles River Watershed was adopted by the Los Angeles RWQCB on August 09, 2007 and subsequently approved by USEPA. The TMDL was been integrated into the Basin Plan as Attachment A of Regional Board Resolution No. 2007-012. | ||||
| Data Reference: | Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region Basin Plan 1997-2009 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | |||||
| Objective/Criterion Reference: | |||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | |||||
| Temporal Representation: | |||||
| Environmental Conditions: | |||||
| QAPP Information: | QA information unavailable. | ||||
| QAPP Information Reference(s): | |||||
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| LOE ID: | 4028 | ||||
| Pollutant: | Trash | ||||
| LOE Subgroup: | Visual | ||||
| Matrix: | Not Specified | ||||
| Fraction: | Not Recorded | ||||
| Beneficial Use: | Non-Contact Recreation | ||||
| 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): | |||||