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Bioassessment and Biocriteria Program Status for Connecticut: Streams and Wadeable Rivers

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State Program Contact

Connecticut Department of Energy and Environmental Protection Exit


Water Quality Standards

WQS Information
The link to Connecticut's WQS that are in effect for Clean Water Act purposes is provided below. These are the WQS approved by EPA.
The state of Connecticut 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 below for your convenience and may or may not reflect the most recently EPA approved WQS. The following links exit the site Exit

Designated Aquatic Life Uses
Habitat for fish and other aquatic life and wildlife

Biological Criteria
__X__ Narrative, with quantitative implementation procedures or translators
_____ Numeric
_____ No criteria

(13) Biological Condition criteria may be utilized where appropriate for assessment of the biological integrity of surface waters
“The Biological Condition Gradient Model is a model that describes how ecological attributes change in response to increasing levels of stressors. In accordance with the Biological Condition Gradient Model, as the level of stress gets progressively greater, the biological communities, which start out in a natural condition, begin to change as they respond to the stress.”
Narrative descriptions of biological condition and BCG tiers for each water quality class (PDF) (69 pp, 678 K) (Page 52)

Antidegradation Policy
Antidegradation policy (PDF)(69 pp, 678 K) Section 22a-426-8 (a) (2)“Factors that may be given consideration when identifying High Quality Waters include but are not limited to the current biological condition, fisheries resources and recreational uses.”


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: Table 1-3, page 16 of IWQR (PDF) (355 pp, 7 MB)

How are assemblages used to make impairment decisions?
Biological assemblages are independently applied, along with other concurrent data (e.g. chemical monitoring) and then a weight of evidence approach is used. This process is under refinement.

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

Biological data, especially fish community information, is being incorporated into Stream flow classifications; See: Connecticut Stream Flow Standards and Regulations


Technical Support Information and Documents:

Reference condition:
Reference condition is typically defined by landuse, and chemical constituents concentration (e.g. chloride < 5 mg/L) if data are available. Depending on the application, other anthropogenic stressors (i.e. dams, water withdrawal, fish stocking) are also considered.

Technical reference material:
Bellucci, C J, M Becker, M Beauchene. 2011. Characteristics of macroinvertebrate and fish communities from 30 least disturbed small streams in Connecticut. Northeastern Naturalist 18:411-444.
Gerritsen J, Jessup B (2007) Calibration of the biological condition gradient for high gradient streams of Connecticut. Report prepared for US EPA Office of Science and Technology and the Connecticut Department of Environmental Protection. TetraTech, Maryland
Stamp, J, Gerritsen J (2013) A biological condition gradient assessment model for stream fish communities of Connecticut-Final Report. Report prepared for US EPA Office of Science and Technology and the Connecticut Department of Environmental Protection. TetraTech, Maryland

Biocriteria:
Development of biocriteria involves the collection and interpretation of biological data –e.g. benthic macroinvertebrates, fish, and periphyton. During this process entities typically use biological metrics (usually aggregated into a multimetric index) and/or multivariate analysis to assess whether a waterbody is meeting its designated aquatic life use(s). The reference materials included below include standard operation procedures used in data collection, compilation, technical approaches used to develop biocriteria as well as its implementation procedures.

Technical reference material: Numeric values are more detailed in CALM for assessments (PDF) (355 pp, 7 MB) (Page 15)
 
Supporting Materials:
Bellucci, C, ME Becker, M Beauchene, L. Dunbar (2013) Classifying the health of Connecticut streams using benthic macroinvertebrates with implications for water management. Environmental Management 51:1274-1283.
Gerritsen J, Jessup B (2007) Calibration of the biological condition gradient for high gradient streams of Connecticut. Report prepared for US EPA Office of Science and Technology and the Connecticut Department of Environmental Protection. TetraTech, Maryland
Kanno Y, Vokoun JC, Beauchene M (2009)Development of dual fishmultimetric indices of biological condition for streams with characteristic thermal gradients and low species richness. Ecol Indic 10:565–571
Stamp, J, Gerritsen J (2013) A biological condition gradient assessment model for stream fish communities of Connecticut-Final Report. Report prepared for US EPA Office of Science and Technology and the Connecticut Department of Environmental Protection. TetraTech, Maryland
 

Stressor identification/causal analysis approach:
Biological monitoring is used to bracket known stressors to determine the most likely cause of impairment. Conceptual model diagrams are a big component of setting up the sampling design and eliminating potential stressors.

Technical reference material:
Bellucci C, G Hoffman, and S Cormier (2010) An Iterative Approach for Identifying the Causes of Reduced Benthic Macroinvertebrate Diversity in the Willimantic River, Connecticut. U.S. Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, Cincinnati, OH. EPA/600/R-08/144.

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