Biocriteria are narrative or numeric expressions that describe the desired biologic integrity (structure and function) of aquatic communities and are used for the assessment and regulation of aquatic ecosystem health. Biocriteria, and the techniques for assessing them, evolve over time. Tasks in this focus area investigate biocriteria and bioassessment approaches, identify factors that influence bioassessment outcomes, and develop tools that address biota-environment questions in natural systems.
Aquatic Ecosystem Assessment
Initiated in 1998, the NCASI Long-term Receiving Water Study (LTRWS) is a long-term (>10 years), multi-faceted, study designed to evaluate potential effluent responses in U.S. receiving waters. Study Streams Willamette River, Oregon LTRWS data are collected on four streams: Codorus Creek, Pennsylvania Leaf River, Mississippi McKenzie River, Oregon Willamette River,…
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A Total Maximum Daily Load (TMDL) is the end product of efforts to quantify the capacity of a waterbody to assimilate substances entering the water from natural and manmade sources. The process of completing a TMDL includes developing an allocation for substances contributed from both point sources (e.g., treated effluent…
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This support document is organized around common questions NCASI has received from its members when applying for NPDES permit renewals and/or responding to draft permits issued by regulatory agencies.
Learn MoreThe Long-Term Receiving Water Study (LTRWS) is an ongoing integrated NCASI study of the physical, chemical, and biological characteristics of US pulp and paper receiving streams.
Learn MorePer- and polyfluoroalkyl substances (PFAS) are a group of high-performance chemicals used in some firefighting applications and to impart properties such as water and stain resistance to various products. Many PFAS are persistent in the environment and are of interest due to their toxicity profiles. This report summarizes the state of knowledge regarding the toxicity of PFAS to aquatic organisms and identifies knowledge gaps that could potentially be filled by targeted studies.
Learn MoreThis NCASI white paper summarizes the current state of science regarding the effects of microplastics in freshwater systems. Specifically, it…
Learn MorePresentations provided updates on Human Health Water Quality Criteria, Per- and Polyfluorinated Substances (PFAS), Microplastics, TSCA Chemical Data Reporting.
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