Draft California 2020 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 1 - North Coast Region

Water Body Name: Eureka Plain HU, Mad River Slough
Water Body ID: CAR1100005219990617094843
Water Body Type: River & Stream
 
DECISION ID
104327
Region 1     
Eureka Plain HU, Mad River Slough
 
Pollutant: Oxygen, Dissolved
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 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.

One line of evidence is available in the administrative record to assess this pollutant. Zero of 44 samples exceed the objective for COLD.

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. Zero of 44 samples exceed the objective for COLD 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 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.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 104327, Oxygen, Dissolved
Region 1     
Eureka Plain HU, Mad River Slough
 
LOE ID: 120374
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 44
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed STORET data for Eureka Plain HU, Mad River Slough to determine beneficial use support and results are as follows: 0 of 44 samples exceeded the water quality standard for Oxygen, Dissolved.
Data Reference: Water quality data for tribal lands submitted through the US EPA STorage and RETrival (STORET) database for the 2018 listing cycle.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Basin, Chapter III, General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states: Dissolved oxygen concentrations shall conform to those limits listed in Section 3.3.5. Section 3.3.5 lists dissolved oxygen concentration limits for COLD beneficial use waters to be a daily minimum of 6.0 mg/L and a 7-day moving average of 8.0 mg/L.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s) (WIYOT_WQX-MRS-1)
Temporal Representation: The samples were collected between the dates of 2010-09-02 and 2012-02-23
Environmental Conditions:
QAPP Information: QAPP not required for federal data
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
 
DECISION ID
104328
Region 1     
Eureka Plain HU, Mad River Slough
 
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 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.

One line of evidence are available in the administrative record to assess this pollutant.
None of the samples exceed the objective for the COLD beneficial use(s).

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. None of the 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 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.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 104328, pH
Region 1     
Eureka Plain HU, Mad River Slough
 
LOE ID: 120456
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 43
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed STORET data for Eureka Plain HU, Mad River Slough to determine beneficial use support and results are as follows: 0 of 43 samples exceeded the water quality standard for pH.
Data Reference: Water quality data for tribal lands submitted through the US EPA STorage and RETrival (STORET) database for the 2018 listing cycle.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Basin, Chapter III, General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 6.5 or raised above 8.5.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s) (WIYOT_WQX-MRS-1)
Temporal Representation: The samples were collected between the dates of 2010-09-02 and 2012-02-23
Environmental Conditions:
QAPP Information: QAPP not required for federal data
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
 
DECISION ID
75598
Region 1     
Eureka Plain HU, Mad River Slough
 
Pollutant: Indicator Bacteria
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Fecal indicator bacteria (which includes fecal coliform) is being considered for placement on the Section 303(d) list under Section 3.2 of the Listing Policy. Under this section a single line of evidence (LOE) is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess fecal indicator bacteria in this water body. Fecal coliform data from the 2012 Integrated Report were assessed under both the shellfish harvesting (SHELL) and the water contact recreation (REC-1) objective, however the data are only counted one time in this decision. In accordance with Section 3.3 of the Listing Policy, a 4% exceedance rate shall be used to add waters to the List "if water quality monitoring was conducted April 1 through October 31 only". However, the data assessed in this decision include data collected during months outside the April - October range. Therefore, this pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy, using a 10% exceedance rate. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against adding this water segment-pollutant combination to the Section 303(d) list (i.e., sufficient justification to not list). This conclusion is based on the staff findings that: (1) The data used satisfy the data quality requirements of Section 6.1.4 of the Policy. (2) The data used satisfy the data quantity requirements of Section 6.1.5 of the Policy. (3) Fecal coliform samples do not exceed the objectives more than 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 Decision Recommendation: This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 75598, Indicator Bacteria
Region 1     
Eureka Plain HU, Mad River Slough
 
LOE ID: 31816
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 203
Number of Exceedances: 5
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Five of the 203 samples collected in the Mad River Slough exceeded the 43MPN/100ml objective.
Data Reference: Data for bacteria in Humboldt Bay, Jan. 2004-Aug. 2010
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Per the Basin Plan (NCRWQCB 2011): At all areas where shellfish may be harvested for human consumption (SHELL), the fecal coliform concentration throughout the water column shall not exceed 43MPN/100ml for a 5-tube decimal dilution test or 49MPN/100ml when a three-tube decimal dilution test is used.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected from two sites in Mad River Slough. Those sites were WQ # 27 and T2a.
Temporal Representation: The samples were collected once a month from 2000 to 2010.
Environmental Conditions:
QAPP Information: The samples were collected under the Management Plan For Commercial Shellfishing In Humboldt Bay, California. California Department of Public Health.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 75598, Indicator Bacteria
Region 1     
Eureka Plain HU, Mad River Slough
 
LOE ID: 33295
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 203
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: The samples were collected from two sites in Humboldt Bay. None of the 203 samples exceeded the evaluation guideline.
Data Reference: Data for bacteria in Humboldt Bay, Jan. 2004-Aug. 2010
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteriological quality of waters of the North Coast Region shall not be degraded beyond natural background levels. In no case shall coliform concentrations in waters of the North Coast Region exceed the following: In waters designated for contact recreation (REC-1), the median fecal coliform concentration based on a minimum of not less than 5 samples for any 30-day period shall not exceed 50 MPN/ 100 ml, nor shall more than 10% of total samples during any 30-day period exceed 400 MPN / 100 ml. Water Quality Control Plan, North Coast Region (NCRWQCB 2011)
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region
 
Evaluation Guideline: Beach posting is recommended when single sample fecal coliform levels exceed 400 MPN / 100 ml. Draft Guidance for Fresh Water Beaches" (DHS 2011).
Guideline Reference: Draft Guidance for Fresh Water Beaches. Last Update: May 8, 2006. Initial Draft: November 1997. California Department of Public Health.
 
Spatial Representation: The samples were collected from two sites in Mad River Slough. Those sites were WQ # 27 and T2a.
Temporal Representation: The samples were collected once a month from 2000 to 2010.
Environmental Conditions:
QAPP Information: The samples were collected under the Management Plan For Commercial Shellfishing In Humboldt Bay, California. California Department of Public Health.
QAPP Information Reference(s):