A draft report of the National Lakes Assessment: A Collaborative Survey of the Nation’s Lakes shows that 56% of the nation’s lakes support healthy biological communities.
It also identifies poor lakeshore habitat and high levels of nutrients as widespread stressors impact lake water quality in the United States.
The National Lakes Assessment (NLA) is the latest in a series of surveys of the nation’s aquatic resources being conducted by EPA and its state and tribal partners.
The NLA provides unbiased estimates of the condition of natural and man-made freshwater lakes, ponds and reservoirs greater than 10 acres and at least one meter deep.
Using a statistical survey design, 1,028 lakes were selected at random to represent the condition of the larger population of lakes across the lower 48 states.
The NLA presents data on the extent of lakes that support healthy biological communities, selected stressors impacting lake quality, and information on recreational indicators of lake condition such as microcystin, an algal toxin which can harm humans, pets, and wildlife.
The NLA also reports on lake trophic status and includes comparisons of current data to 1972 data on wastewater-impacted lakes.
A draft report of the National Lakes Assessment: A Collaborative Survey of the Nation’s Lakes is available for public review at: www.epa.gov/lakessurvey