Water quality data and assessment results reported by states, tribes, territories and others are stored in various EPA-managed data systems. EPA and its partners, such as the U.S. Geological Survey, have also developed mapping tools to help display this information visually.

Databases | Mapping

Databases

• Assessment Database (ADB) - a state-operated database application for tracking water quality assessment data, including use attainment, and causes and sources of impairment.

• Electronic Integrated Reporting under Sections 305(b) and 303(d) (Water Quality Assessment and TMDL Information) - This database, known as ATTAINS, displays information provided by the states in their biennial integrated water quality assessment reports.

• 2002 National Assessment Database (NAD) - EPA's interactive summary of water quality assessment information reported by the states in 2002 under Section 305(b) of the Clean Water Act.

• STORET (data STOrage and RETrieval system) - STORET is a national repository for water quality, biological, and physical data. This page includes an overview of the current STORET system, explains how to download STORET data from the web, has technical details for STORET users, and more.

Mapping

• Watershed Assessment, Tracking and Environmental Results (WATERS) - The WATERS information system uses EPA's standard mapping application to display water quality information about local waters. WATERS unifies information about water quality goals from several EPA databases.

• National Hydrography Dataset (NHD) - The National Hydrography Dataset is a comprehensive coverage of hydrographic data for the U.S.. It was developed by combining EPA Reach File version 3 (RF3) and the USGS Digital Line Graph (DLG) coverages.