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EPA Issues Rivers and Streams Assessment, Seeks Comment on Modernizing Survey Methods

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WASHINGTON (December 31, 2020) — Today, the U.S. Environmental Protection Agency (EPA) announced the availability of a final report—National Rivers and Streams Assessment (NRSA) 2013-2014: A Collaborative Survey—that provides a historical snapshot of water quality in U.S. rivers and streams. The agency is seeking input on all aspects of the design and implementation of the National Aquatic Resource Survey (NARS) program to improve future assessments. The NRSA report includes a comparison between water quality metrics in 2013-2014 and 2008-2009, which generally show that water quality in rivers and streams across the country remained relatively unchanged between 2008 and 2014.

“As EPA celebrated its 50th Anniversary this year, the Office of Water highlighted significant progress in restoring and protecting our nation’s rivers and streams which are vital to protecting public health while supporting diverse ecosystems and the economy,” said EPA Assistant Administrator for Water David Ross. “With today’s announcement, the agency is continuing to advance the science of water quality assessment so that we can better measure our progress in the next 50 years.”

EPA acknowledges that the NARS assessment methods, which in some cases are based on approaches that are three decades old, may not reflect the best scientific methods currently available. EPA intends to modernize and improve the scientific methods and approaches that are utilized in the NARS program so that the development of future assessments will be more transparent and the surveys can better and more quickly inform the public about the quality of our nation’s surface waters.

EPA is seeking input on all aspects of the design and implementation of the NARS program, including the reference site-based benchmark approach currently used to assess river and stream quality in the contiguous U.S. under the NRSA. EPA is specifically requesting comment on revisions to the calculation of thresholds and benchmarks for assessing human health fish tissue indicators. EPA is also requesting comment on other approaches in the NRSA report, including the use of “good,” “fair,” and “poor” waterbody classification categories and the methods and statistical approaches used for analyzing and presenting differences in water quality among surveys. The input received will be used by EPA to inform potential changes to the NRSA specifically and the NARS program in general.

Going forward, EPA intends to develop a website to host the NARS program data and will transition to presenting survey results in a more user-friendly web-based interface. Learn more about the National Rivers and Streams Assessment at: