This data is compiled and analyzed every two-years/bi-annually. The percentage of rivers and streams fully supporting aquatic life has decreased slightly (2%) from the last reporting period. In 80% of Vermont's rivers and streams, the aquatic organisms are considered healthy and support fishing uses. The remaining 20% are either impaired (due to pollution or altered flow/hydro dams that don't currently meet water quality standards) or the health of the aquatic biota is unknown. Over time, updated assessment data shows areas where we have been successful in river and stream restoration as well as areas where we have identified new impairments or alterations, making overall progress slow. Implementation of regulatory and voluntary measures is expected to help improve the water quality of our rivers and streams and their uses for fishing; however, it is expected to take many years to show substantial progress.

Data contained in the ATTAINS assessment database is reviewed and stream miles that are not meeting water quality standards for Aquatic Biota Use are summed and subtracted from the total river miles