The USGS has released a new report, Prioritization of Constituents for National and Regional Scale Ambient Monitoring of Water and Sediment in the United States, that addresses the methodology used to prioritize constituents to be assessed. This effort was undertaken in preparation for the third decade of the National Water – Quality Assessment Program (NAWQA) including the time period 2013-2023.
Constituents were prioritized by the NAWQA National Target Analyte Strategy Work Group on the basis of available information on physical and chemical properties, observed or predicted environmental occurrence and fate, and observed or anticipated adverse effects on human health or aquatic life.
The constituents were ranked in three tiers:
- Tier 1 with those having the highest priority on the basis of their likelihood of environmental occurrence in ambient water or sediment, or likelihood of effects on human health or aquatic life;
- Tier 2 for constituents of intermediate priority on the basis of their lower likelihood of environmental occurrence or lower likelihood of effects on human health or aquatic life; and
- Tier 3 of those with low or no priority for monitoring.
Overall, 2,541 constituents were assessed with 1,081 constituents identified for ranking in Tier 1. Constituent groups included volatile organic compounds in water; pesticides in water or sediment; pharmaceuticals and hormones in water or sediment; trace elements and other inorganic constituents in water or sediment; cyanotoxins in surface water; lipophilic organic compounds in sediment; disinfection byproducts in water; high-production-volume chemicals in water; wastewater-indicator and industrial compounds in water; and radionuclides in water.
USGS began the NAWQA program in 1991 to develop long-term and consistent information on U.S. streams, rivers, and groundwater, how the conditions are changing over time, and how natural features and human activities affect these features, according to the USGS website.
The USGS report is available at http://pubs.usgs.gov/sir/2012/5218/sir12-5218.pdf.