Final 2008 California 303(d)/305(b) Integrated Report

Supporting Information

Regional Board 8 - Santa Ana Region

Water Body Name: Serrano Creek
Water Body ID: CAR8011100020080921203908
Water Body Type: Coastal & Bay Shoreline
 
DECISION ID
13351
 
Pollutant: Escherichia coli (E. Coli)
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
 
Weight of Evidence: This pollutant is being considered for placement on the 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.

One (1) line of evidence is available in the administrative record to assess this pollutant. Thirty-six (36) of the samples exceed the water quality 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 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. Thirty-six (36) of sixty-nine (69) samples exceed the 1986 USEPA Recommended Ambient Water Quality Criteria for Bacteria 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.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that though this water body's E. coli data exceeds EPA's Recommended Criteria it is not appropriate at this time to list it as impaired. There is a Storm Water Quality Task Force working on determining the appropriate indicators and the appropriate criteria to protect body contact recreation in fresh waters. Listing this waterbody for E. coli would circumvent a much needed process that is currently underway. Regional Board staff actively participate in this process with the SWQTF and will recommend review of this data in the 2010 listing cycle by when the appropriate criteria and indicators will have been developed.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 13351
 
LOE ID: 21469
 
Pollutant: Escherichia coli (E. Coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 69
Number of Exceedances: 36
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Of the 69 samples taken, 36 exceeded EPA's Recommended single sample standard. The exceedances took place in two locations: Ser1 and Ser 2
Data Reference: Orange County Coast Keeper Coastal Watersheds Project
 
Water Quality Objective/Criterion: USEPA Recommended Ambient Water Quality Criteria for Bacteria -1986: E. coli: log mean less than 126 organisms/100 mL based on five or more samples per 30–day period, and not more than 10% of the samples exceed 235 organisms/100mL for any 30 day period.
Objective/Criterion Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Serrano 1 is Located in Lake Forest in the upper Serrano Channel in Trabuco Rd and Peachwood under the bridge.
Serrano 2 is Located in Irvine in the lower Serrano Channel. Next to the Alton/Barranca intersection.
Temporal Representation: The samples were taken monthly starting with March 11, 2004 through March 29, 2006.
Environmental Conditions: Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: The data's quality is deemed appropriate because it was obtained under the auspices of a QAPP approved by the Regional Board.
QAPP Information Reference(s):
 
DECISION ID
13353
 
Pollutant: Ammonia (Unionized)
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: 2022
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One (1) line of evidence is available in the administrative record to assess this pollutant. Twenty-one of the samples exceed the water quality 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 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. Twenty-one (21) of fifty (50) samples exceed the Basin Plan Objective 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.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 13353
 
LOE ID: 8522
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 50
Number of Exceedances: 21
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Of the 50 samples collected, 21 exceeded the Basin Plan's objective. Eight of these exceedances occurred in the Ser 1 sampling station and 13 of them occurred in the Ser 2 sampling station.
Data Reference: Orange County Coast Keeper Coastal Watersheds Project
 
Water Quality Objective/Criterion: Basin Plan Objective: The objective varies according to the temperature of the water being sampled and ranged during the sampling period as follows: 0.19 mg/l - 0.51 mg/l
Objective/Criterion Reference: Water Quality Control Plan-Santa Ana Region
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at two stations in Serrano Creek: Ser 1 and Ser 2
Temporal Representation: The samples were taken monthly starting with 3/11/2004 through 3/29/2006
Environmental Conditions:
QAPP Information: The data's quality is deemed acceptable because it was collected under the auspices of a Regional Board staff's approved quality assurance plan.
QAPP Information Reference(s):
 
DECISION ID
13354
 
Pollutant: pH
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: 2022
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

One (1) line of evidence is available in the administrative record to assess this pollutant. Thirty-one (31) of the samples exceed the water quality 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 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. Thrity-one (31) of seventy-three (73) samples exceed the Basin Plan 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.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 13354
 
LOE ID: 21446
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 73
Number of Exceedances: 31
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Of the 73 samples collected, 31 samples exceeded the Basin Plan's Objective. All the exceedances occurred at the Serrano 2 site.
Data Reference: Orange County Coast Keeper Coastal Watersheds Project
 
Water Quality Objective/Criterion: Basin Plan Objective: The ph of inland surface waters shall not be raised above 8.5 pH units or depressed below 6.5 pH units as a result of controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan-Santa Ana Region
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at two stations: Serranon1 and Serrano 2. Serrano 1 is Located in Lake Forest in the upper Serrano Channel at Trabuco Rd. and Peachwood under the bridge.
Serrano 2 is Located in Irvine in the lower Serrano Channel next to gthe Alton/Barranca intersection.
Temporal Representation: The samples were collected monthly beginning on March 11, 2004 through March 29, 2006.
Environmental Conditions:
QAPP Information: The data's quality is deemed acceptable because it was collected under the auspices of a Regional Board staff's approved quality assurance plan.
QAPP Information Reference(s):