EPA no longer updates this information, but it may be useful as a reference or resource.
Welcome to the STORET Legacy Data Center, site of the world's largest repository of ambient Water Quality Data. From this site you will be able to access a database that holds over 200 million water sample observations from about 700,000 sampling sites for both surface and ground water.This web site allows both scientists and the general public to access the historical data from the legacy STORET system. First-time users should narrow their search based on the options from the Query page, while experienced users may jump to the no-frills Advanced Query form for requesting data. Legacy STORET contains data of undocumented quality. Further, the data in this system is static, and all new data are being entered into Modernized STORET.
Background information about the Office of Water and the history of STORET may be found by following the Purpose link. For more information on the layout of this site, please follow the Site Map link.