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Bioassessment and Biocriteria Program Status for District of Columbia: Streams and Wadeable Rivers

State Program Contact

District of Columbia Department of Energy and Environment Exit

Water Quality Standards

WQS Information
The link to District of Columbia' WQS that are in effect for Clean Water Act purposes is provided. These are the WQS approved by EPA.
The District of Columbia provided information and links to sections of their administrative code on designated aquatic life use, biological criteria, antidegradation as well as technical support documents and information on its bioassessment and biocriteria programs. These are included for your convenience and may or may not reflect the most recently EPA approved WQS. The following links exit the site Exit

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Designated Aquatic Life Uses
The District of Columbia has a single use related to ALU. There are no specific use categories.

Class C of the District’s water quality standards- Protection and propagation of fish, shellfish and wildlife.

1104.5     Class C streams shall be maintained to support aquatic life and shall not be placed in pipes.

1104.6     Within tidally influenced Class C waters, concentrations of chlorophyll a in free-floating microscopic aquatic plants (algae) shall not exceed levels that result in ecologically undesirable consequences such as reduced water clarity, low dissolved oxygen, food supply imbalances, proliferation of species deemed potentially harmful to aquatic life or humans or aesthetically objectionable conditions or otherwise render tidal waters unsuitable for designated uses.

Biological Criteria
_____ Narrative statement
_____ Numeric
__X__ No criteria

Antidegradation Policy
Provisions addressing antidegradation are in Title 21 of the District of Columbia Municipal Regulations, Chapter 11, Section 1102.

Biological Assessment

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

Are bioassessments used to support 303(d) listings?
Yes. Listing methodology: District of Columbia Water Quality Assessment 2020 Integrated Report (PDF) (350 pp, 5 MB)

How are assemblages used to make impairment decisions?
Independently applied - an impairment in any individual metric for the assemblages (invertebrate, fish or periphyton) denotes a use impairment

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

Technical Support Information and Documents:

Reference condition:
The Maryland Biological Stream Survey’s reference sites in the Sentinel Site Network for the corresponding geographic region as the streams under assessment are currently used as the reference sites.

Technical reference material:
A Multi-Year Update (2011 – 2014) to Maryland Biological Stream Survey’s Sentinel Site Network (PDF) (210 pp, 7 MB)

Not applicable.

Stressor identification/causal analysis approach:
Not applicable.