Last week the U.S. Environmental Protection Agency (EPA) released the most detailed and comprehensive lake survey on the ecological and water quality of U.S. lakes that has ever been carried out. The survey compiles data on 1,028 lakes from state, tribal and internal sources. Just over half of the U.S.’s lakes are rated as “good,” which is either good or bad news, depending on if you are a glass half empty or glass half full kind of person.
“This survey serves as a first step in evaluating the success of efforts to protect, preserve, and restore the quality of our nation’s lakes. Future surveys will be able to track changes in lake water quality over time and advance our understanding of important regional and national patterns in lake water quality,” said Peter Silva, EPA Office of Water, Assistant Administrator.
The survey looked at the overall health of the lakes and rated them as good, fair or poor: 56% were rated good, and the rest were either fair or poor.
Other significant numbers from the survey include:
36% of lakes rated “poor” because of degraded lakeshore habitat. This was largest of the problems documented by the survey and covers things like tree removal and any kind of structures built on or along the shore, from docks to houses.
20% of lakes returned high levels of nitrogen and phosphorus. These lead to a variety of issues in the lakes, including algae blooms and low water clarity.
75% of lakes in a subset that were tested in the 1970’s because of wastewater impacts showed improvements or no change in their phosphorus levels.
The survey is notable as it is the first time all monitoring groups have used a consistent system of assessment throughout the country, which will be an important baseline for future water conservation and quality management efforts. This information will become increasingly important as numbers are put on climate change targets and international assessment becomes necessary.