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National Water-Quality Assessment Program (NAWQA)
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National Synthesis teams synthesize the results of all the NAWQA study-unit investigations with information from other programs, agencies, and researchers. These national syntheses are possible because each NAWQA study-unit investigation adheres to a nationally consistent study design and uniform methods of data collection and analysis. National syntheses provide an understanding of how and why water quality varies regionally and nationally.

National Synthesis results help to answer the following types of questions:

  • What water-quality issues occur only in isolated areas, and what issues are pervasive across the nation?
  • How do the effects on water quality of human activities, such as pesticide applications, and natural factors, such as soil permeability, differ across different environmental settings?

National Synthesis addresses priority water-quality issues:

Models are critical tools in National Synthesis:
SPARROW (Spatially Referenced Regression on Watershed attributes), a national water-quality model developed by the USGS

National Synthesis results include data and publications:
NAWQA data warehouse
The Quality of Our Nation's Waters-Nutrients and Pesticides, USGS Circular 1225 (1999)

NAWQA Intranet (Internal Use Only)


 U.S. Department of the Interior, U.S. Geological Survey
 Contact for NAWQA:
 Maintainer: James Ulrich-
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