Bioassessment and Biocriteria Program Status for New Hampshire: Streams and Wadeable Rivers

State Program Contact

New Hampshire Department of Environmental Services

Water Quality Standards

• Water Quality Standards Regulations: New Hampshire

• New Hampshire's Water Quality Standards (PDF)
• State of New Hampshire 2020 Section 305(b) and 303(d) Consolidated Assessment and Listing Methodology (PDF)

Designated Aquatic Life Uses
Most applicable designated uses related to aquatic life use include fish/shellfish consumption, wildlife, and primary and secondary contact recreation.

Physical, chemical, toxicological, biological and/or habitat indicators can be used to assess the aquatic life use. DES uses a weight of evidence approach to make final assessment decisions. Factors not only include the type of data, but the time, location and quantity of samples collected. 

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

Env-wq 1703.19 (a) Biological and Aquatic Community Integrity (PDF)
The surface waters shall support and maintain a balanced, integrated, and adaptive community of organisms having a species composition, diversity, and functional organization comparable to that of similar natural habitats of a region

Antidegradation Policy
Use of biocriteria or bioassessments not included in antidegradation policy (PDF) (PART Env-Wq 1708)

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: NHDES Consolidated Assessment Listing Methodology (PDF)

How are assemblages used to make impairment decisions?
Macroinvertebrate and fish impairment thresholds are both initially evaluated independently for the state’s wadeable streams. If both assemblages exceed impairment thresholds, the waterbody would be listed as impaired for aquatic life use, unless reasons for not listing exist. If only one of the assemblages exceed impairment thresholds, they are further evaluated.

Other uses of biocriteria or bioassessment within the water quality program:
Non-point source assessments, 305(b) surface water condition assessments, restoration goals, and Section 401 Certifications

Technical Support Information and Documents:

Reference condition:
Reference sites are defined according to the index being developed.

Technical reference material:
NHDES Publications

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 include standard operation procedures used in data collection, compilation, technical approaches used to develop biocriteria as well as its implementation procedures.

Stressor identification/causal analysis approach:
Physical and chemical water quality parameters along with periodic habitat assessments are informally used to support potential stressors or causes of impairment.