An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Water Quality Data Download

Water quality data submitted from over 900 federal, state and tribal agencies, watershed organizations and other groups are available to support your water quality analyses. Water quality data includes physical, chemical, biological, habitat, metrics and indexes data. Data can be retrieved from the following sources:

Water Quality Portal

The Water Quality Portal (WQP) is a cooperative service sponsored by the United States Geological Survey (USGS), the Environmental Protection Agency (EPA) and the National Water Quality Monitoring Council (NWQMC). It serves over 380 million water result records from EPA STORET/WQX, the USGS National Water Information System (NWIS) and the U.S. Department of Agriculture Sustaining the Earth's Watersheds, Agricultural Research Data System (STEWARDS).

Top of Page

Legacy Data

The LDC (Legacy Data Center) contains historical water quality data dating back to the early part of the 20th century and collected up to the end of 1998. Data is no longer being placed in the Legacy Data Center, but the public can still access data from the ftp site:

Top of Page

Back to Main Water Quality Data (WQX) Page

Return to Main Water Quality Data (WQX) Page.

Water Quality Data Upload with WQX

There are two options for you to share your data using WQX. You can choose a standard web-based application (WQX Web) that uses Microsoft Excel spreadsheets or you can choose to create a custom submission application using WQX XML schema through Exchange Network Nodes or Node Clients.

Learn More about Water Quality Data

General Information, Data Assistance, Tools, Training Videos, User Community, and Funding.