State Program Contact

State Water Resources Control Board Exit

Water Quality Standards

• Water Quality Standards Regulations: California

• Region 1: North Coast Basin Plan
• Region 2: San Francisco Bay Basin Planning
• Region 3: Central Coast Region – Basin Plan
• Region 4: Los Angeles Basin Plan
• Region 5: Central Valley Basin Planning
• Region 6: Lahontan Basin Plan
• Region 7: Colorado River Basin – Basin Planning
• Region 8: Santa Ana Region Basin Plan
• Region 9: San Diego Region - The Basin Plan

• Warm freshwater habitat
• Cold freshwater habitat
• Migration Spawning
• Wildlife habitat
• Rare and endangered species
• Marine habitat
• Wetland
• Inland saline water habitat
• Estuarine habitat
• Contact recreation (fishing)
• Non-contact recreation
• Shellfish harvesting
• Cultural uses
• Limited warm water habitat
• Commercial/sport fishing

Biological Criteria
_____ Narrative
_____ Numeric
__X__ No criteria

The State Water Resources Control Board does not have adopted numeric or narrative biocriteria and there is no biocriteria being developed. However, there is a Statewide implementation plan for assessing biological integrity in perennial streams that is under development at this time. 

Antidegradation Policy
Not applicable.

Biological Assessment

What biological assemblages are used in the bioassessment program?
Benthic macroinvertebrates and periphyton

Are bioassessments used to support 303(d) listings?
Yes. Listing methodology: Water Quality Control Policy for Developing California’s Clean Water Act Section 303(d) List (PDF) (32 pp, 306 K)

From the Water Quality Control Policy for Developing California’s Clean Water Act Section 303(d) List (Listing Policy), Section 3.9: “A water segment shall be placed on the section 303(d) list if the water segment exhibits significant degradation in biological populations and/or communities as compared to reference site(s) and is associated with water or sediment concentrations of pollutants including but not limited to chemical concentrations, temperature, dissolved oxygen, and trash. This condition requires diminished numbers of species or individuals of a single species or other metrics when compared to reference site(s). The analysis should rely on measurements from at least two stations. Comparisons to reference site conditions shall be made during similar season and/or hydrologic conditions.  Association of chemical concentrations, temperature, dissolved oxygen, trash, and other pollutants shall be determined using sections 3.1, 3.2, 3.6, 3.7, 6.1.5.9, or other applicable sections.

For population or community degradation related to sedimentation, the water segment shall be placed on the section 303(d) list if degraded populations or communities are identified and effects are associated with clean sediment loads in water or with loads stored in the channel when compared to evaluation guidelines (satisfying the conditions of section 6.1.3) using the binomial distribution as described in section 3.1 or as compared to reference sites. Bioassessment data used for listing decisions shall be consistent with section 6.1.5.8. For bioassessment, measurements at one stream reach may be sufficient to warrant listing provided that the impairment is associated with a pollutant(s) as described in this section.”

How are assemblages used to make impairment decisions?
Historically, individual Benthic Macro Invertebrate assemblage data were assessed using a Regional Index of Biological Integrity (IBI) score. The score from each assemblage was summarized in a Line of Evidence and considered along with all other water quality data from the same water body in order to make 303(d) Listing/Delisting decision recommendations. In the future, the Regional IBIs will be replaced with the new California Stream Condition Index (CSCI) scoring tool for water quality assessment purposes to determine impairment.  

Other uses of biocriteria or bioassessment within the water quality program:
TMDL development and assessment, non-point source assessments, BMP evaluation, 305(b) surface water condition assessments, and restoration goals

Technical Support Information and Documents:

Reference condition:
The State’s Surface Water Ambient Monitoring Program (SWAMP) has developed “Recommendations for the Development and Maintenance of a Reference Condition Management Program (RCMP) to Support Biological Assessment of California’s Wadeable Streams”

Technical reference material:
Recommendations for the Development and Maintenance of a Reference Condition Management Program (RCMP) to Support Biological Assessment of California’s Wadeable Streams (PDF) (47 pp, 1 MB)

Biocriteria:
California has not adopted numeric or narrative biocriteria. However, the state is currently developing an implementation plan for assessing biological integrity in perennial streams.

Technical reference material:
Proposed Biological Integrity Assessment Implementation Plan for (Perennial Streams & Rivers of) the State of California

Stressor identification/causal analysis approach:
Building on the existing CADDIS tools developed by USEPA, California has funded four causal assessment pilot projects and developed “Causal Assessment Evaluation and Guidance for California”. This document evaluates the US Environmental Protection Agency's Causal Analysis/Diagnostic Decision Information System. Associated strengths and shortcomings of CADDIS for California are presented to provide regulated and regulatory agencies a path forward for improving future Causal Assessments.

Technical reference material:
Causal Assessment Evaluation and Guidance for California (PDF) (44 pp, 5 MB)

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