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Bioassessment and Biocriteria Program Status for Rhode Island: Streams and Wadeable Rivers

State Program Contact

Rhode Island Department of Environmental Management Exit

Water Quality Standards

WQS Information
The link to Rhode Island's WQS that are in effect for Clean Water Act purposes is provided. These are the WQS approved by EPA.
The state of Rhode Island provided information and links to sections of their administrative code on designated aquatic life use, biological criteria, and antidegradation. These are included for your convenience and may or may not reflect the most recently EPA approved WQS.

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Designated Aquatic Life Uses
All waters have been categorized according to their water use classification (Class AA, Class A, Class B1, Class B, Class C). All classes have the same ALU designation “for Fish and Wildlife habitat.” Some waterbodies have been assigned a fisheries designation as a “cold or warm-water fishery," but that is not part of the designated uses. The 305(b) Designated use for “Aquatic Life Support/Fish, other Aquatic Life, and Wildlife” under the RI WQ Regulations Designated Use is listed as “Fish and Wildlife Habitat."

Refer to link to Regulations or page 7 of the CALM (PDF) (50 pp, 542 K)

Biological Criteria
__X__ Narrative statement
_____ Numeric
_____ No criteria

  1. General Criteria - The following minimum criteria are applicable to all waters of the State, unless criteria specified for individual classes are more stringent:
    1. At a minimum, all waters shall be free of pollutants in concentrations or combinations or from anthropogenic activities subject to these regulations that:
      1. Adversely affect the composition of fish and wildlife;
      2. Adversely affect the physical, chemical, or biological integrity of the habitat;
      3. Interfere with the propagation of fish and wildlife;
      4. Adversely alter the life cycle functions, uses, processes and activities of fish and wildlife; or
      5. Adversely affect human health.
    2. Aesthetics - all waters shall be free from pollutants in concentrations or combinations that:
      1. Settle to form deposits that are unsightly, putrescent, or odorous to such a degree as to create a nuisance, or interfere with the existing or designated uses;
      2. Float as debris, oil, grease, scum or other floating material attributable to wastes in amounts to such a degree as to create a nuisance or interfere with the existing or designated uses;
      3. Produce odor or taste or change the color or physical, chemical or biological conditions to such a degree as to create a nuisance or interfere with the existing or designated uses; or
      4. Result in the dominance of species of fish and wildlife to such a degree as to create a nuisance or interfere with the existing or designated uses.

Antidegradation Policy
Use of biocriteria or bioassessment not included in antidegradation policy (Water Quality Regulations: Section 1.20)

Biological Assessment

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

Are bioassessments used to support 303(d) listings? 
Yes. Listing methodology: 2020 CALM (PDF)(50 pp, 542 K) (page 23)

How are assemblages used to make impairment decisions?
We use just one assemblage to make impairment decisions as described in the CALM (PDF) (50 pp, 542 K) (page 23)

Other uses of biocriteria or bioassessment within the water quality program:
305(b) surface water condition assessments

Technical Support Information and Documents:

Reference condition:
The reference condition has been characterized for high-gradient wadeable stream sites in the Southern New England Coastal Plains and Hills Level IV Ecoregion, and a separate reference condition is currently under development for low-gradient wadeable sites. For the high gradient sites, the reference condition is characterized using a range of landscape data and water chemistry data. The following criteria were used to designate reference sites: >90% natural landcover, <5% Impervious cover, density of RIPDES discharges must be <0.1 per mile, density of CERCLIS=0, density of CSOs=0, conductivity < 150 microsemens and dissolved oxygen >5 mg/L.

Technical reference material:
Entire report is not online, but can be requested from RIDEM Office of Water Resources.

Not available.

Stressor identification/causal analysis approach:
Not applicable.

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