This data is compiled and analyzed every two-years/bi-annually; annual fluctuations are expected due to updated assessment data reflecting the current conditions on our waters. There are over 55,000 acres of lakes in the state of Vermont; of these acres 87% support swimming/recreational uses. The remaining 13% are consistently limited due to aquatic invasive species. A slight decrease (1%) was reported in the overall condition of the health of Vermont lakes during this most recent reporting period. 

Data contained in the ATTAINS assessment database is reviewed and stream miles that are not meeting water quality standards for Recreation-Swimming are summed and subtracted from the total river miles.