| Pollutant: |
Indicator Bacteria |
| 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: |
Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. |
| |
| 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. 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. |
| |
| State Board Review of Regional Board Conclusion and Recommendation: |
|
| |
| State Board Decision Recommendation: |
|
| |
| |
Line of Evidence (LOE) for Decision ID 148544, Indicator Bacteria
|
Region 2 |
Alhambra Creek (Contra Costa County) |
|
| |
| LOE ID: |
299886 |
| |
| Pollutant: |
Escherichia coli (E. coli) |
| LOE Subgroup: |
Pollutant-Water |
| Matrix: |
Water |
| Fraction: |
STV |
| |
| Beneficial Use: |
Water Contact Recreation |
| |
| Number of Samples: |
1 |
| Number of Exceedances: |
1 |
| |
| Data and Information Type: |
PATHOGEN MONITORING |
| Data Used to Assess Water Quality: |
Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Alhambra Creek (Contra Costa County) to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly. |
| Data Reference: |
Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2. |
| |
| SWAMP Data: |
Non-SWAMP |
| |
| Water Quality Objective/Criterion: |
The bacteria water quality objective to protect the REC-1 beneficial use where the salinity is less than 1 parts per thousand 95 percent or more of the time applies a statistical threshold value to E. coli of 320 cfu/100 mL, not to be exceeded by more than 10 percent of samples within a calendar month (ISWEBE 2018). |
| Objective/Criterion Reference: |
Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy |
| |
| Evaluation Guideline: |
|
| Guideline Reference: |
| |
| Spatial Representation: |
The samples were collected at 1 monitoring site(s), station(s): 207R04544 (Alhambra Creek, near the intersection of Brookside Dr and F St). |
| Temporal Representation: |
The samples were collected between the days of 2017-07-24 and 2017-07-24 . |
| Environmental Conditions: |
|
| QAPP Information: |
EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. |
| QAPP Information Reference(s): |
BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan |
| |