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

Supporting Information

Regional Board 1 - North Coast Region

Water Body Name: Mad River HU, Norton Creek
Water Body ID: CAR1091002019990617100545
Water Body Type: River & Stream
 
DECISION ID
80103
Region 1     
Mad River HU, Norton Creek
 
Pollutant: Indicator 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)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2025
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Fecal indicator bacteria (which includes E. coli and fecal coliform) are being considered for placement on the Section 303(d) list under Section 3.2 and 3.3 of the Listing Policy. Under these sections a single line of evidence (LOE) is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess indicator bacteria in this water body.

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". The E. coli data collected in Norton Creek (LOE 31865), the fecal coliform data collected in a road side ditch (LOE 31866), and the E. coli data collected in Widow White Creek (LOE 47490) were collected during this timeframe only. One of two E. coli samples from Norton Creek and one of two fecal coliform samples from the road side ditch violate the evaluation guideline, however these sample sizes are insufficient to determine with the power and confidence of the listing policy if standards are being met as there must be either (1) at least 22 samples available for evaluation in order to make a listing determination or (2) 3 or more exceedances from less than 22 samples in which case listing can occur. Seven of 8 E. coli samples collected in Widow White Creek exceed the evaluation guideline and this violates the allowed 4% exceedance frequency.

The fecal coliform data assessed in LOE 31830 for Widow White Creek includes data collected during months outside the April - October range. Therefore, the data are being considered under section 3.2 of the Listing Policy, using a 10% exceedance rate. Four of 9 fecal coliform samples from Widow White Creek exceed the evaluation guideline, and this sample size is insufficient to determine with the power and confidence of the listing policy if standards are being met as there must be either (1) at least 26 samples available for evaluation in order to make a listing determination under section 3.2 or (2) 5 or more exceedances from less than 26 samples in which case listing can occur.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for adding Widow White Creek to the Section 303(d) list for fecal indicator bacteria (i.e., sufficient justification to 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) 7 of 8 E. coli samples from Widow White Creek violate the objective and this exceeds the allowable 4% exceedance frequency from 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 80103, Indicator Bacteria
Region 1     
Mad River HU, Norton Creek
 
LOE ID: 31866
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: One of the two samples exceeded the fecal coliform evaluation guideline. Since less than 5 samples over a 30-day period were collected, the evaluation guideline is used for comparison to the samples.
Data Reference: Data for bacteria in various North Coast Region water bodies
 
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 duringany 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 Roadside ditch, tributary to Widow White Creek.
Temporal Representation: The samples were collected in September and November 2006.
Environmental Conditions:
QAPP Information: The samples were collected under the Redwood Community Action Agency's Humboldt Bay First Flush Quality Assurance Project Plan.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 80103, Indicator Bacteria
Region 1     
Mad River HU, Norton Creek
 
LOE ID: 31830
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 9
Number of Exceedances: 4
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Four of the nine samples exceeded the fecal coliform evaluation guideline. Since less than 5 samples over a 30-day period were collected, the evaluation guideline is used for comparison to the samples.
Data Reference: Data for bacteria in various North Coast Region water bodies
 
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 Widow White Creek at Cental and Widow White Creek at Murray Rd.(stations M003 and M005).
Temporal Representation: The samples were collected between September 2006 to May 2008.
Environmental Conditions:
QAPP Information: The samples were collected under the Redwood Community Action Agency's Humboldt Bay First Flush Quality Assurance Project Plan.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 80103, Indicator Bacteria
Region 1     
Mad River HU, Norton Creek
 
LOE ID: 47490
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 8
Number of Exceedances: 7
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Seven of the eight samples exceeded the E. coli evaluation guideline.
Data Reference: Data for bacteria in various North Coast Region water bodies
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2011): The bacteriological quality of waters of the North Coast Region shall not be degraded beyond natural background levels.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region
 
Evaluation Guideline: Draft Guidance for Fresh Water Beaches (CDPH 2011): Beach posting is recommended when single sample E. coli levels exceed 235 MPN / 100 ml.
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 Widow White Creek, stations M003 and M005.
Temporal Representation: The samples were collected September 2008 to October 2009.
Environmental Conditions:
QAPP Information: The samples were collected under the Redwood Community Action Agency's Humboldt Bay First Flush Quality Assurance Project Plan.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 80103, Indicator Bacteria
Region 1     
Mad River HU, Norton Creek
 
LOE ID: 31865
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: One of the two samples exceeded the E. coli evaluation guideline.
Data Reference: Data for bacteria in various North Coast Region water bodies
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2011): The bacteriological quality of waters of the North Coast Region shall not be degraded beyond natural background levels.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region
 
Evaluation Guideline: Draft Guidance for Fresh Water Beaches (CDPH 2011): Beach posting is recommended when single sample E. coli levels exceed 235 MPN / 100 ml.
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 Norton Creek, tributary to Widow White Creek.
Temporal Representation: The samples were collected in September and October 2009.
Environmental Conditions:
QAPP Information: The samples were collected under the Redwood Community Action Agency's Humboldt Bay First Flush Quality Assurance Project Plan.
QAPP Information Reference(s):