Bioassessment and Biocriteria Program Status for New York: Streams and Wadeable Rivers
State Program Contact
New York State Department of Environmental Conservation Biomonitoring Exit
Water Quality Standards
The link to New York's WQS that are in effect for Clean Water Act purposes is provided. These are the WQS approved by EPA.
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Designated Aquatic Life Uses
Presently the recognized designated uses of NYS surface waters includes; source of water supply, culinary or food processing purposes, public bathing, recreation, and fish consumption. In addition to these explicit uses, the description of each surface water class contains language that suggests the “waters shall be suitable for fish, shellfish, and wildlife propagation and survival.” Suitability for fish, shellfish, and wildlife propagation and survival is evaluated in surface waters where applicable.
Evaluation of suitability is performed using standard biological monitoring techniques of macroinvertebrates, fish, and algae. Biological community condition is estimated on a four tiered scale of water quality impact. Freshwater Classes AA, A, B, C, D.
The aquatic life use in non tidal rivers and streams is assessed using benthic macroinvertebrate community indices (refer to standard operating procedure). These waters are supplemented with a broad suite of biologically relevant physical/chemical data (e.g., dissolved oxygen, temperature, nutrients).
__X__ No criteria
Use of biocriteria or bioassessment are not included in the antidegradation policy.
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: Section 303(d) Listing Methodology (PDF)(18 pp, 134 K) and Section 305(b) Assessment Methodology (PDF)(549 pp, 289 K)
How are assemblages used to make impairment decisions?
Water quality assessments are primarily conducted using benthic macroinvertebrates. Fish and algal communities are assessed on a project specific basis to assist in clarifying stressor type. Currently multiple assemblage data are applied independently however ongoing research may result in a combined approach.
Other uses of biocriteria or bioassessment within the water quality program:
Refining ALU, TMDL development and assessment, non-point source assessments, 305(b) surface water condition assessments, and restoration goals
Technical Support Information and Documents:
Reference sites are selected to be representative of the highest water quality or best attainable condition in a basin. They are visited during each return cycle to a basin. These sites are selected using landscape characteristics and historical datasets. Total natural cover (forest, wetland, open water etc…) is typically greater than or equal to 75% and impervious surface cover is usually less than 2%. These values may vary depending on the characteristics of the watershed. In addition previous water quality determinations should be non-impacted without record of variability in the assessment categories. However, in some heavily disturbed watersheds the best attainable condition may not be non-impacted. In such cases the highest water quality designation should be used. Water chemistries if available should indicate background condition. A good surrogate for water chemical information is specific conductance and it should be less than 150 µsiemen/cm which is the 25th percentile of all data collected in New York State’s ambient water quality monitoring program but should not exceed 250 µsiemen/cm.
Stressor identification/causal analysis approach:
NY uses Impact Source Determination (ISD) as a procedure for identifying types of impacts that result in deleterious effects on a waterbody. ISD uses macroinvertebrate community types or models to ascertain the primary factor influencing the fauna (refer to standard operating procedure).