Database

Disclaimer

Most of the data in this database is from EPA's legacy STOrage and RETrival (STORET) data system, a database containing information from many state and federal agencies. EPA incorporated Legacy STORET data that were considered relevant into the database and removed duplicate data. The accuracy of the data is a function of the quality assurance / quality control procedures used by the data originators. EPA checked with the data originators to determine the overall reliability of the data (e.g., which analytical methods and sampling techniques were used to gather data). The data contained in the database do not constitute EPA's recommendations for nutrient criteria but have been used as a basis for developing EPA ecoregional nutrient criteria. If any of the data contained in the database appears to be inaccurate or of questionable quality, please contact Ost.Comments@epa.gov to initiate data correction.

The National Nutrient Database stores and analyzes nutrient water quality data and serves as an information resource for states, tribes, and others in establishing scientifically defensible numeric nutrient criteria. Fact sheet about the database (September 2001).

Query Tool

You can use the database to derive ecoregion- and waterbody-specific numeric nutrient criteria ranges. EPA converted STOrage and RETrieval legacy data, National Stream Quality Accounting Network data, National Water-Quality Assessment data, and other data into the Nutrient Criteria Database. With this Query Tool, you can retrieve nutrient information either by state or ecoregion. Please select a query option to go to a screen where you can select more parameters (e.g., waterbody type). For more information on the queries, consult the Query Tool Help.

Mapping Analysis Tool

The mapping analysis tool allows you to generate maps identifying Nutrient Stations with a selected parameter, whose values are above or below the 25th percentile of all the stations selected. Maps can be generated by aggregate ecoregion, subecoregion, and state. The statistics were calculated using the median values for each waterbody.

Statistical Analysis Tool

The statistical analysis tool allows you to generate statistical reports and graphs by aggregate ecoregion, subecoregion, and state. Results can be grouped by year or for individual years. The statistics were calculated using the median values for each waterbody. The Data Source and Remark Code reports were created using all observations.

Download Tool

You can download nutrient information either by state or ecoregion. Once you select a state or ecoregion, the query engine will return a screen with a list of files available for download. Definitions of the fields are available.