This tool was produced by the National Aquatic Resource Surveys (NARS) program of the U.S. Environmental Protection Agency (EPA). The NARS program conducts large-scale studies of the quality of the nation's waters. One such study is the National Lakes Assessment (NLA). This tool allows you to input water quality data for a lake you care about, then see it compared to statistically representative data collected by the NLA. You'll view comparisons to the national, regional and state level. This is currently possible using 2012 and 2017 NLA data for any of four important and common indicators of water quality:

• Secchi Depth (a measure of water clarity)
• Total Phosphorus (a nutrient that can trigger problematic algal blooms)
• Total Nitrogen (another such nutrient)
• Chlorophyll a (a measure of algal population)

The United States Environmental Protection Agency (EPA) GitHub project code is provided on an "as is" basis and the user assumes responsibility for its use. EPA has relinquished control of the information and no longer has responsibility to protect the integrity , confidentiality, or availability of the information. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply their endorsement, recommendation or favoring by EPA. The EPA seal and logo shall not be used in any manner to imply endorsement of any commercial product or activity by EPA or the United States Government.