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

State Program Contact

Ohio EPA Statewide Biological and Water Quality Monitoring and Assessment Exit

Water Quality Standards

WQS Information
The link to Ohio's WQS that are in effect for Clean Water Act purposes is provided. These are the WQS approved by EPA.
The state of Ohio 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

  • Warmwater Habitat
  • Exceptional Warmwater Habitat
  • Coldwater Habitat
  • Modified Warmwater Habitat
  • Seasonal Salmonid
  • Limited Warmwater Habitat (being phased out)
  • Limited Resource Water

Biological Criteria
__X__ Narrative statement
__X__ Numeric
_____ No criteria

Provisions addressing biological criteria are in paragraph (C) of rule 3745-1-07 of the OAC

Biological criteria presented in table 7-1 of this rule provide a direct measure of attainment of the warmwater habitat, exceptional warmwater habitat and modified warmwater habitat aquatic life uses. Biological criteria and the exceptions to chemical-specific or whole-effluent criteria allowed by this paragraph do not apply to any other use designations.

Antidegradation Policy
Provisions addressing antidegradation are in rule 3745-1-05 and rule 3745-1-54 of the Ohio Administrative Code (OAC).

Biological Assessment

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

Are bioassessments used to support 303(d) listings?
Yes. Listing Methodology: Ohio Integrated Water Quality Monitoring and Assessment Report

How are assemblages used to make impairment decisions?
Applied independently

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

Technical Support Information and Documents:

Reference condition:
All reference sites were originally screened to eliminate sites with evidence of substantial human disturbance. This was accomplished by examining maps of human population density and current and past land uses, compiling a watershed disturbance ranking, and noting the size and location of point source discharges. Additional site-specific factors considered in the selection of a reference site included (1) the amount, if any, of stream channel modification, (2) the condition of the vegetative riparian buffer zone,(3) water volume, (4) channel morphology characteristics, (5) substrate character and condition, (6) presence of obvious color/odor problems, (7) amount of in-stream woody debris, and (8) the general representativeness of the site within the ecoregion.

Technical Reference Material:
Biological Criteria for the Protection of Aquatic Life

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:
Biological Criteria for the Protection of Aquatic Life

Stressor identification/causal analysis approach:
Linked stressor identification and causal analysis

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