Draft California 2016 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: Rio Hondo Reach 2 (At Spreading Grounds)
Water Body ID: CAR4051501019990202114543
Water Body Type: River & Stream
 
DECISION ID
32501
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Ammonia
Final Listing Decision: Delist from 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: Delist from 303(d) list (being addressed by USEPA approved TMDL)(2012)
Revision Status Revised
Reason for Delisting: Applicable WQS attained; due to restoration activities
TMDL Name: Los Angeles River Nitrogen (11)
TMDL Project Code: 229
Date TMDL Approved by USEPA: 03/18/2004
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status.

Five 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 for removing this water segment-pollutant combination from the section 303(d) list.

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 301 samples exceeded the Basin Plan pH and temperature dependent acute ammonia criteria and zero of 100 samples exceeded the Basin Plan pH and temperature dependent chronic ammonia criteria use, and two of 50 exceed the objective and this does not exceed the allowable frequency listed in Table 4.1 of the Listing Policy.
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Staff Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be removed from the section 303(d) list because applicable water quality standards for the pollutant are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 32501, Ammonia
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 28216
 
Pollutant: Ammonia
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 301
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: Zero of 301 samples exceeded the acute criteria for ammonia and one out of 100 samples exceeded the chronic criteria. Temperature and pH data corresponding to the ammonia samples were used for analysis. Temperature values ranged from 11.7 C to 32.8 C. Sample pH values ranged from 7.02 to 9.16. Samples are from the County Sanitation Districts of Los Angeles, Whittier Narrows Water Reclamation Plant (WNRP) Monitoring Reports 2003-2007
Data Reference: Whittier Narrows Water Reclamation Plant (WNRP) -Monitoring Reports 2003-2007
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The acute (1-hour average) and chronic (4-day average) concentrations for ammonia are the highest concentrations of to which aquatic life can be exposed for a short period and an extended period of time, respectively, without deleterious effects applicable to protect aquatic life Beneficial Uses. These criteria are pH and temperature dependent and vary accordingly. The ammonia objectives and the pH and temperature dependent formulas are found in Attachment A of Regional Board Resolution No. 2002-011.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Two receiving water monitoring stations: RD located 1000 ft upstream from San Gabriel Boulevard, downstream of WNRP Discharge point 004, and RD-1 100ft upstream of WNRP Discharge point 004.
Temporal Representation: Weekly and monthly samples collected and analyzed from October 2003 to January 2008.
Environmental Conditions:
QAPP Information: Data collected for compliance with NPDES Permit No. CAS-004001 Monitoring and Reporting Programs.
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
 
Line of Evidence (LOE) for Decision ID 32501, Ammonia
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 2485
 
Pollutant: Ammonia
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 36
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Based on 30-day average concentrations of ammonia, no samples of 36 total samples exceed the ammonia objective. Ambient measurements of pH and temperature (30-day averages) were used to calculate the water quality objective. (LACSD, 2004b).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: In order to protect aquatic life, ammonia concentrations in inland surface waters characteristic of freshwater shall not exceed the values calculated for the appropriate instream conditions [both pH and temperature] shown in Tables 3-1 to 3-3 [in the Basin Plan] (per U.S. EPA's most recent criteria guidance document, '1999 Update of Ambient Water Quality Criteria for Ammonia').
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Three stations.
Temporal Representation: Samples were collected from February 2001 through November 2004. New management practices were begun at the beginning of this period and may have resulted in a change in water quality. Water quality measurements collected before the implementation of management measures were not considered representative of current conditions.
Environmental Conditions:
QAPP Information: NPDES quality assurance.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 32501, Ammonia
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 2483
 
Pollutant: Ammonia
LOE Subgroup: Narrative Description Data
Matrix: Not Specified
Fraction: None
 
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: An alternative enforceable program is in place that will address ammonia water quality standards exceedances for this reach. In June 1995, the seven water reclamation plants discharging in the San Gabriel River and Santa Clara River watersheds received NPDES permits containing requirements regarding compliance with the Basin Plan water quality objectives for ammonia. In accordance with these permits, the Los Angeles County Sanitation Districts have been pursuing the addition of nitrification and denitrification facilities at each of these plants to comply with the ammonia objectives. By June 2003, it is expected that these new facilities will be operational and ammonia will be drastically reduced. Research facility operation shows that the monthly average ammonia concentration will fully comply with the chronic ammonia objective. Objective is expected to be applicable in June 2003.
It is probable that the majority of ammonia discharged to this water body was contributed by POTWs. Information in the record indicates that the majority (over 95%) of the ammonia in the Los Angeles River was contributed by POTWs. Also, it is probable that the contribution in the San Gabriel River watershed is dominated by contributions from POTWs as well. Generally, concentrations of ammonia upstream of the treatment plants are much lower than downstream concentrations (up to an order of magnitude difference).
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):
 
Line of Evidence (LOE) for Decision ID 32501, Ammonia
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87440
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 26
Number of Exceedances: 2
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: Two of the 26 30-day averages exceeded the objective for ammonia. A total of 59 samples were collected. Only samples during the months when early life stages were present were assessed. A calendar month was considered as a 30-day averaging period.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Los Angeles Regional Water Quality Control Plan 30-day site specific objective for total ammonia as nitrogen is a function of pH, temperature, and the presence of early life stages. The site specific objective for Rio Hondo (Upstream of Whittier Narrows Dam) has early life stages present April 1st through September 30th.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at site Whittier Narrows Long River Run RD-1.
Temporal Representation: Samples were collected weekly from June 2005 to September 2006. Samples were collected monthly from October 2006 to July 2009. Only samples during the months when early life stages were present were assessed.
Environmental Conditions:
QAPP Information: Samples were collected as part of an NPDES permit requirement. Receiving water data collected to represent the water body as a whole. No QAPP was submitted but an unsigned field manual was.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 32501, Ammonia
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87439
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 24
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: None of the 24 30-day averages exceeded the objective for ammonia. A total of 43 samples were collected. Only samples during the months when early life stages were absent were assessed. A calendar month was considered as a 30-day averaging period.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Los Angeles Regional Water Quality Control Plan 30-day site specific objective for total ammonia as nitrogen is a function of pH, temperature, and the presence of early life stages. The site specific objective for Rio Hondo (Upstream of Whittier Narrows Dam) has early life stages absent October 1st through March 31st.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at site Whittier Narrows Long River Run RD-1.
Temporal Representation: Samples were collected weekly from June 2005 to September 2006. Samples were collected monthly from October 2006 to July 2009. Only samples during the months when early life stages were absent were assessed.
Environmental Conditions:
QAPP Information: Samples were collected as part of an NPDES permit requirement. Receiving water data collected to represent the water body as a whole. No QAPP was submitted but an unsigned field manual was.
QAPP Information Reference(s):
 
 
DECISION ID
66109
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Aluminum
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
8 of the 19 samples exceeded the aquatic life CRITERION.

Pursuant to Section 304(a) of the Clean Water Act, U.S. EPA is intending to release updated National Recommended Water Quality Criteria for Aluminum (Al) in spring 2017. Therefore, the Los Angeles Water Board is not recommending listing waterbodies for Al in the current listing cycle and is planning to use the updated criteria in the 2022 listing cycle.
 
Regional Board Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 66109, Aluminum
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87416
 
Pollutant: Aluminum
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 19
Number of Exceedances: 8
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: Eight of the 19 samples exceeded the criteria of 87 ug/L.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: National Recommended Water Quality Criteria Continuous Concentrations are intended protect aquatic organisms from chronic exposures (expressed as 4-day average concentration) in freshwater. The evaluation guideline for aluminum is 87 ug/L to protect warm freshwater habitat.
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: Samples were collected from Rio Hondo Reach 2 (above Spreading Grounds) at sample location WN (also called SG) at two sublocations: RD and RD1.
Temporal Representation: Samples were collected monthly from June 2006 through May of 2010.
Environmental Conditions:
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66091
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Arsenic
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 36 samples exceeded the CRITERIA.

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. 0 of 36 samples exceeded the CRITERIA 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 Staff 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 because applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 66091, Arsenic
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87417
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 36
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: None of the 36 samples exceeded the criteria of 150 ug/L.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use. California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The CTR for arsenic is 150 ug/L.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
  Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Rio Hondo Reach 2 (above Spreading Grounds) at sample location WN (also called SG) at two sublocations: RD and RD1.
Temporal Representation: Samples were collected monthly from June 2006 through May of 2010.
Environmental Conditions:
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66092
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Cadmium
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 44 samples exceeded the CRITERIA.

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. 0 of 44 samples exceeded the CRITERIA 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 Staff 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 because applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 66092, Cadmium
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87418
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 44
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: None of the 44 samples exceeded the hardness adjusted criteria.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use. California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion. If no hardness data were available, a value of 100 mg/L was used.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
  Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Rio Hondo Reach 2 (above Spreading Grounds) at sample location WN (also called SG) at two sublocations: RD and RD1.
Temporal Representation: Samples were collected monthly from June 2006 through May of 2010.
Environmental Conditions:
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66093
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Chromium
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

2 lines of evidence are available in the administrative record to assess this pollutant.
0 of 36 samples exceeded the CRITERIA.
0 of 30 samples exceeded the CRITERIA.

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. 0 of 36 and 0 of 30 samples exceeded the CRITERIA 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 Staff 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 because applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 66093, Chromium
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87420
 
Pollutant: Chromium, hexavalent
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 30
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: None of the 30 samples exceeded the criteria of 11 ug/L.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use. California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The CTR for hexavalent chromium is 11 ug/L.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
  Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Rio Hondo Reach 2 (above Spreading Grounds) at sample location WN (also called SG) at two sublocations: RD and RD1.
Temporal Representation: Samples were collected monthly from June 2006 through May of 2010.
Environmental Conditions:
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 66093, Chromium
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87419
 
Pollutant: Chromium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 36
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: None of the 36 samples exceeded the hardness adjusted criteria.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use. California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion. If no hardness data were available, a value of 100 mg/L was used.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
  Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Rio Hondo Reach 2 (above Spreading Grounds) at sample location WN (also called SG) at two sublocations: RD and RD1.
Temporal Representation: Samples were collected monthly from June 2006 through May of 2010.
Environmental Conditions:
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66094
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Copper
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 64 samples exceeded the CRITERIA.

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. 0 of 64 samples exceeded the CRITERIA 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 Staff 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 because applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 66094, Copper
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87421
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 64
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: None of the 64 samples exceeded the hardness adjusted criteria.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use. California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion. If no hardness data were available, a value of 100 mg/L was used.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
  Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Rio Hondo Reach 2 (above Spreading Grounds) at sample location WN (also called SG) at two sublocations: RD and RD1.
Temporal Representation: Samples were collected monthly from June 2006 through May of 2010.
Environmental Conditions:
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66105
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Diazinon
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 0 sample exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA section 303(d) List. 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. 0 of 0 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 66105, Diazinon
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87422
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: The reporting limit for the non-detect sample was 0.05 which is equal to the evaluation guideline, therefore these data are not of sufficient resolution to determine if water quality standards are being achieved.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Region 4 Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The screening criteria is 0.05 ug/L, chronic 4-day average. Water quality criteria for Diazinon and Chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game.
Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
 
Spatial Representation: A total of six samples were collected at sampling locations, RH_WN_R-D and RH_WN_R-D-1 . Location description:Whittier Narrows Station RSW-005 (Station R-D)
Temporal Representation: Six water samples were collected at both RH_WN_R-D and RH_WN_R-D-1 in 2/16/2010, 5/10/2010, and 11/09/2009.
Environmental Conditions: There was no special environmental conditions reported.
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66104
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Endosulfan
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 2 samples exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA section 303(d) List. 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. 0 of 2 samples exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 66104, Endosulfan
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87423
 
Pollutant: Endosulfan
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: None of the two samples exceeded the water quality criteria/objective.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Region 4 Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The California Toxic Rule Endosulfan I and II criteria for fresh aquatic life protection continuous concentration (4-day average)is 0.056 ug/L.
Guideline Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Spatial Representation: A total of two samples were collected at sampling locations, RH_WN_R-D and RH_WN_R-D-1 . Location description:Whittier Narrows Station RSW-005 (Station R-D).
Temporal Representation: Two water samples were collected at both RH_WN_R-D and RH_WN_R-D-1 in 2/16/2010.
Environmental Conditions: There was no special environmental conditions reported.
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66107
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Heptachlor epoxide
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 0 sample exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA section 303(d) List. 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. 0 of 0 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 66107, Heptachlor epoxide
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87425
 
Pollutant: Heptachlor epoxide
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: The reporting limit for the non-detect sample was .01 ug/L which is greater than the evaluation guideline, therefore these data are not of sufficient resolution to determine if water quality standards are being achieved.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Region 4 Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: California Toxic Rule criteria fresh aquatic life protection continuous concentration (4-day average)is 0.0038 ug/L.
Guideline Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Spatial Representation: A total of two samples were collected at sampling locations, RH_WN_R-D and RH_WN_R-D-1. Location description:Whittier Narrows Station RSW-005 (Station R-D)
Temporal Representation: Two water samples were collected at both RH_WN_R-D and RH_WN_R-D-1 in 2/16/2010.
Environmental Conditions: There was no special environmental conditions reported.
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66095
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Lead
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 64 samples exceeded the CRITERIA.

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. 0 of 64 samples exceeded the CRITERIA 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 Staff 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 because applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 66095, Lead
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87431
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 64
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: None of the 64 samples exceeded the hardness adjusted criteria.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use. California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion. If no hardness data were available, a value of 100 mg/L was used.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
  Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Rio Hondo Reach 2 (above Spreading Grounds) at sample location WN (also called SG) at two sublocations: RD and RD1.
Temporal Representation: Samples were collected monthly from June 2006 through May of 2010.
Environmental Conditions:
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66101
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Mercury
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 44 samples exceeded the CRITERIA.

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. 0 of 44 samples exceeded the CRITERIA 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 Staff 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 because applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 66101, Mercury
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87432
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 44
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: None of the 44 samples exceeded the criteria of 0.77 ug/L.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: National Recommended Water Quality Criteria Continuous Concentrations (4-day average concentrations) for freshwater aquatic organisms exposure to elemental mercury is 0.77 ug/L.
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: Samples were collected from Rio Hondo Reach 2 (above Spreading Grounds) at sample location WN (also called SG) at two sublocations: RD and RD1.
Temporal Representation: Samples were collected monthly from June 2006 through May of 2010.
Environmental Conditions:
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66102
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Nickel
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 36 samples exceeded the CRITERIA.

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. 0 of 36 samples exceeded the CRITERIA 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 Staff 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 because applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 66102, Nickel
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87433
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 36
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: None of the 36 samples exceeded the hardness adjusted criteria.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use. California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion. If no hardness data were available, a value of 100 mg/L was used.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
  Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Rio Hondo Reach 2 (above Spreading Grounds) at sample location WN (also called SG) at two sublocations: RD and RD1.
Temporal Representation: Samples were collected monthly from June 2006 through May of 2010.
Environmental Conditions:
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66099
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 102 samples exceeded the CRITERIA.

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. 0 of 102 samples exceeded the CRITERIA 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 Staff 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 because applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 66099, Nitrate/Nitrite (Nitrite + Nitrate as N)
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87434
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 102
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: None of the 102 composite samples exceeded the objective for nitrate + nitrite. Sampling data for both nitrate and nitrite were summed to determine whether sampling data met the water quality objectives.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan for the Los Angeles Region site specific objective for Nitrogen (Nitrate + Nitrite as N) in Rio Hondo above Santa Ana Freeway is 8 mg/L. From table 3-8 titled "Water Quality Objectives for Selected Constituents in Inland Surface Waters".
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at site Whittier Narrows Long River Run RD-1.
Temporal Representation: Samples were collected June 2005 to July 2009.
Environmental Conditions:
QAPP Information: Samples were collected as part of an NPDES permit requirement. Receiving water data collected to represent the water body as a whole. No QAPP was submitted but an unsigned field manual was.
QAPP Information Reference(s):
 
 
DECISION ID
66114
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
2 of 50 samples exceeded the CRITERIA.

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. 2 of 50 samples exceeded the CRITERIA 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 Staff 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 because applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 66114, Nitrogen, ammonia (Total Ammonia)
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87439
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 24
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: None of the 24 30-day averages exceeded the objective for ammonia. A total of 43 samples were collected. Only samples during the months when early life stages were absent were assessed. A calendar month was considered as a 30-day averaging period.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Los Angeles Regional Water Quality Control Plan 30-day site specific objective for total ammonia as nitrogen is a function of pH, temperature, and the presence of early life stages. The site specific objective for Rio Hondo (Upstream of Whittier Narrows Dam) has early life stages absent October 1st through March 31st.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at site Whittier Narrows Long River Run RD-1.
Temporal Representation: Samples were collected weekly from June 2005 to September 2006. Samples were collected monthly from October 2006 to July 2009. Only samples during the months when early life stages were absent were assessed.
Environmental Conditions:
QAPP Information: Samples were collected as part of an NPDES permit requirement. Receiving water data collected to represent the water body as a whole. No QAPP was submitted but an unsigned field manual was.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 66114, Nitrogen, ammonia (Total Ammonia)
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87440
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 26
Number of Exceedances: 2
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: Two of the 26 30-day averages exceeded the objective for ammonia. A total of 59 samples were collected. Only samples during the months when early life stages were present were assessed. A calendar month was considered as a 30-day averaging period.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Los Angeles Regional Water Quality Control Plan 30-day site specific objective for total ammonia as nitrogen is a function of pH, temperature, and the presence of early life stages. The site specific objective for Rio Hondo (Upstream of Whittier Narrows Dam) has early life stages present April 1st through September 30th.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at site Whittier Narrows Long River Run RD-1.
Temporal Representation: Samples were collected weekly from June 2005 to September 2006. Samples were collected monthly from October 2006 to July 2009. Only samples during the months when early life stages were present were assessed.
Environmental Conditions:
QAPP Information: Samples were collected as part of an NPDES permit requirement. Receiving water data collected to represent the water body as a whole. No QAPP was submitted but an unsigned field manual was.
QAPP Information Reference(s):
 
 
DECISION ID
66098
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Selenium
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 36 samples exceeded the CRITERIA.

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. 0 of 36 samples exceeded the CRITERIA 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 Staff 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 because applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 66098, Selenium
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87443
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 36
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: None of the 36 samples exceeded the criteria of 5 ug/L.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use. California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The CTR for selenium is 5.0 ug/L.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
  Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Rio Hondo Reach 2 (above Spreading Grounds) at sample location WN (also called SG) at two sublocations: RD and RD1.
Temporal Representation: Samples were collected monthly from June 2006 through May of 2010.
Environmental Conditions:
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66097
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Silver
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 56 samples exceeded the CRITERIA.

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. 0 of 56 samples exceeded the CRITERIA 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 Staff 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 because applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 66097, Silver
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87444
 
Pollutant: Silver
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 56
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: None of the 56 samples exceeded the hardness adjusted criteria.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use. California Toxics Rule (CTR) lists criterion maximum concentrations for silver to protect aquatic life in freshwater (1-hour average). The silver criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion. If no hardness data were available, a value of 100 mg/L was used.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
  Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Rio Hondo Reach 2 (above Spreading Grounds) at sample location WN (also called SG) at two sublocations: RD and RD1.
Temporal Representation: Samples were collected monthly from June 2006 through May of 2010.
Environmental Conditions:
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66106
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Toxaphene
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 0 sample exceeded the CRITERIA.

Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA section 303(d) List. 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. 0 of 0 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
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 Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 66106, Toxaphene
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87451
 
Pollutant: Toxaphene
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Since the criteria is smaller than the reporting limit and method detection limit, none of samples can be counted.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: Criteria Continuous Concentration (4-day Average) is 0.0002 ug/L
Guideline Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Spatial Representation: A total of two samples were collected at sampling locations, RH_WN_R-D and RH_WN_R-D-1 . Location description:Whittier Narrows Station RSW-005 (Station R-D)
Temporal Representation: Two water samples were collected at both RH_WN_R-D and RH_WN_R-D-1 in 2/16/2010.
Environmental Conditions: There was no special environmental conditions reported.
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66096
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Zinc
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
0 of 64 samples exceeded the CRITERIA.

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. 0 of 64 samples exceeded the CRITERIA 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 Staff 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 because applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 66096, Zinc
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87453
 
Pollutant: Zinc
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 64
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: None of the 64 samples exceeded the hardness adjusted criteria.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use. California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion. If no hardness data were available, a value of 100 mg/L was used.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
  Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Rio Hondo Reach 2 (above Spreading Grounds) at sample location WN (also called SG) at two sublocations: RD and RD1.
Temporal Representation: Samples were collected monthly from June 2006 through May of 2010.
Environmental Conditions:
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66154
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: pH
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
3 of 66 samples exceeded the OBJECTIVE.

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. 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. 3 of 66 samples exceeded the OBJECTIVE and this does not exceed 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 not met.
 
Regional Board Staff 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 because applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 66154, pH
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87442
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 66
Number of Exceedances: 3
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Numeric data generated from 66 averages of pH had 3 exceedences.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The pH of all inland surface waters shall not be depressed below 6.5 or raised above 8.5 as a result of waste discharges.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from the WN-RD1 (SG-RD1) station.
Temporal Representation: Samples were collected approximately once a month from July 2005 to November 2009.
Environmental Conditions:
QAPP Information: NPDES quality assurance.
QAPP Information Reference(s):
 
 
DECISION ID
66110
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Iron
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: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
3 of 32 samples exceeded the CRITERIA.

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 CWA section 303(d) List. 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. 3 of 32 samples exceeded the CRITERIA 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 not met.
 
Regional Board Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 66110, Iron
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87430
 
Pollutant: Iron
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 32
Number of Exceedances: 3
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: Three of the 32 samples exceeded the criteria of 1,000 ug/L.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: National Recommended Water Quality Criteria Continuous Concentrations are intended protect aquatic organisms from chronic exposures (expressed as 4-day average concentration) in freshwater. The evaluation guideline for iron is 1,000 ug/L to protect warm freshwater habitat.
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: Samples were collected from Rio Hondo Reach 2 (above Spreading Grounds) at sample location WN (also called SG) at two sublocations: RD and RD1.
Temporal Representation: Samples were collected monthly from June 2006 through May of 2010.
Environmental Conditions:
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66113
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Oxygen, Dissolved
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: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
41 of 105 samples exceeded the OBJECTIVE.

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 CWA section 303(d) List. 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. 41 of 105 samples exceeded the OBJECTIVE 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 not met.
 
Regional Board Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 66113, Oxygen, Dissolved
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87441
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 105
Number of Exceedances: 41
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Numeric data generated from 105 averages of Dissolved Oxygen concentrations had 41 exceedences.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Dissolved Oxygen Water Quality Objective of all surface waters designated as Warm Fresh Water Aquatic Habitat shall not be depressed below 5 mg/l.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from the WN-RD1 (SG-RD1) station.
Temporal Representation: Samples were collected approximately once a month from July 2005 to November 2009.
Environmental Conditions:
QAPP Information: NPDES quality assurance.
QAPP Information Reference(s):
 
 
DECISION ID
66146
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
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: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
5 of 31 samples exceeded the GUIDELINE.

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 CWA section 303(d) List. 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. 5 of 31 samples exceeded the GUIDELINE 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 not met.
 
Regional Board Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 66146, Toxicity
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87452
 
Pollutant: Toxicity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 31
Number of Exceedances: 5
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: Toxicity data was not reported with a control, therefore anything reported as < 100 (chronic) or <100% survival (acute) was considered an exceedance. Two of the eleven fathead minnow chronic-survival tests were less than 100% and three of the eleven fathead minnow chronic-growth were less than 100; these were grouped to make a total of three of eleven exceedances. All of the eleven ceriodaphnia chronic survival and growth tests were reported at 100 (0 of 11 exceedances). Two of the nine acute tests on the fathead minnow were less than 100% survival (2 of 9 exceedances).
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Toxic pollutants shall not be present at levels that will bioaccumulate in aquatic life to levels which are harmful to aquatic life or human health. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: Toxicity is defined as being significantly different than the control using a t-test or other valid statistical test.
Guideline Reference: Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
 
Spatial Representation: Samples were collected from Rio Hondo Reach 2 (At Spreading Grounds) from location WN at sublocation RD1.
Temporal Representation: Samples were collected quarterly from June 2006 through May of 2010.
Environmental Conditions:
QAPP Information: The Biology Department of the San Jose Creek Water Quality Laboratory is responsible for collecting samples from receiving water stations along the San Gabriel River, Coyote Creek, San Jose Creek, Santa Clara River, and the Rio Hondo River. Data is collected for the Los Angeles Sanitation District NPDES permits. Some standard operating procedures for sampling were submitted, however no QA Project Plan was.
QAPP Information Reference(s):
 
 
DECISION ID
66155
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Indicator Bacteria
Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
TMDL Name: Los Angeles River Pathogens (15)
TMDL Project Code: 238
Date TMDL Approved by USEPA: 03/23/2012
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for placement on the CWA 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.

1 line of evidence is available in the administrative record to assess this pollutant.
16 of 35 samples exceeded the OBJECTIVE.

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 CWA section 303(d) List. 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. 16 of 35 samples exceeded the OBJECTIVE 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 not met.

There is sufficient justification to place this waterbody/pollutant in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by USEPA, and is expected to result in attainment of the standard.

This conclusion is based on the staff findings that:
1. The Los Angeles River Bacteria TMDL was approved by USEPA on 03/23/2012.
 
Regional Board Staff 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.
 
 
Line of Evidence (LOE) for Decision ID 66155, Indicator Bacteria
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 4385
 
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):
 
Line of Evidence (LOE) for Decision ID 66155, Indicator Bacteria
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 87424
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 35
Number of Exceedances: 16
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Sixteen of the thirty-five samples exceeded the E. coli objective.
Data Reference: Data for Various Pollutants in Various Water Bodies in Sanitation Districts of Los Angeles County, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The E. coli density shall not exceed 235/100 ml. Water Quality Control Plan for the Los Angeles Region.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Spatial Representation: The samples were collected Whittier Narrows Station RSW-005 (Station R-D) and Whittier Narrows Station RSW-006 (Station RD-1)
Temporal Representation: The samples were collected weekly from June 2005 to 2006 and monthly from 2007 October 2009.
Environmental Conditions:
QAPP Information: The samples were collected under the San Jose Creek Laboratory sample collection methods.
QAPP Information Reference(s):
 
 
DECISION ID
35152
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
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)(2012)
Revision Status Original
Sources: Source Unknown
Expected TMDL Completion Date: 2009
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: 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 Staff Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
 
Line of Evidence (LOE) for Decision ID 35152, Coliform Bacteria
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 4385
 
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
44719
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
Pollutant: Cyanide
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)(2012)
Revision Status Original
Sources: Source Unknown
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: Regional Board Conclusion:
The Los Angeles Regional Water Quality Control Board (Region 4), for the 2008 listing cycle, had incorrectly assessed and listed Rio Hondo Reach 1 for cyanide. The State Water Board is responding to Region 4's request to correct this error. The data and information for Rio Hondo Reach 1 has been retired and Rio Hondo Reach 2 is being assessed for cyanide.

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. Three of six samples exceed the CTR chronic criteria and one of six samples exceed both the CCC and CMC criteria 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.

State Board Review and Conclusion:
The Los Angeles Water Board staff assessed Rio Hondo Reach 1 for Cyanide instead of the appropriate reach, Reach 2. The Los Angeles Water Board approved the listing of Reach 1 for Cyanide. The Regional Water Board staff asked State Water Board staff to correct the error and place the correct water segment on 303(d) list. State Water Board staff evaluated the information and propose to remove the Rio Hondo Reach 1 from the 303 (d) list and to List the Rio Hondo Reach 2 for Cyanide.
 
Regional Board Staff Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
 
Line of Evidence (LOE) for Decision ID 44719, Cyanide
Region 4     
Rio Hondo Reach 2 (At Spreading Grounds)
 
LOE ID: 30913
 
Pollutant: Cyanide
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 3
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: Three of six samples exceeded the CTR CCC limit and one of six samples exceeded the CMC limit. Data from the County of Los Angeles Stormwater Monitoring Report 2003/04
Data Reference: Monitoring Report (MS4 Data) - 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
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: CTR Criteria Continuous Concentration of 0.0052 mg/L is the highest concentration of cyanide to which aquatic life can be exposed for an extended period of time (four days) without deleterious effects applicable to protect aquatic life Beneficial Uses. The CTR Criteria Maximum Concentration CMC of 0.022 mg/l is the highest concentration of cyanide to which aquatic life can be exposed for a short period of time without deleterious effects. These criteria are linked and applicable for the protection of aquatic life Beneficial Uses.
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One stormwater monitoring station: TS06 located on Beverly Blvd, downstream of Whittier Narrows dam, at the USGS - U.S. Army Corps of Engineers (ACOE) Stream gage No. 1102300 or E327-R.
Temporal Representation: Grab samples collected and analyzed over the 2003-04 storm year.
Environmental Conditions:
QAPP Information: Data collected for compliance with NPDES Permit No. CAS-004001 Monitoring and Reporting Programs.
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