This page provides an overview of new additions to the Nitrogen and Phosphorus Pollution Data Access Tool. To receive update emails (no more than a few per year) on new data added to the Data Access Tool, please contact npdat-hq@epa.gov.

October 12, 2012

• Updated Data on Facilities Likely to Discharge N/P to Water
  The Facilities Likely to Discharge Nitrogen/Phosphorus (N/P) to Water data layer now provides information on nitrogen and phosphorus discharge and any nitrogen and phosphorus permit limits from 2010 facility monitoring reports (previously 2008 information was the most current information available through the Nitrogen and Phosphorus Pollution Data Access Tool) . These data are retrieved using EPA's Discharge Monitoring Report (DMR) Pollutant Loading Tool.
• Updated Data on Waters Listed for N/P Impairments and Waters with N/P TMDLs
  The data layers with Waters Listed for N/P Impairments and Waters with N/P TMDLs [Total Maximum Daily Loads] now reflect data pulled from the Assessment TMDL Tracking and ImplementatioN System (ATTAINS) as of May 2012 (previously the layers reflected November 2011 ATTAINS data).

February 17, 2012

• EPA Adds Drinking Water Data to NPDAT
  Public water system (PWS) data reported to the EPA Safe Drinking Water Information System (SDWIS) have been added to the NPDAT. The drinking water sources for public water systems are summarized on a 12-digit HUC watershed basis. Drinking water from both surface and ground water sources (corresponding to surface water intakes and groundwater wells) are reported.
• EPA Updates Waters Listed for N/P Impairments and Waters with N/P TMDLs Data in NPDAT
  The Waters Listed for Nitrogen/Phosphorus (N/P) Impairments and Waters with N/P TMDLs [Total Maximum Daily Loads] data layers are updated to reflect data pulled from the Assessment TMDL Tracking and ImplementatioN System (ATTAINS) as of November 2011 (previously the layers reflected May 2011 ATTAINS data).

January 31, 2012

• Archived version of Nov. 30, 2011 Webinar "Tools for Developing State Nitrogen and Phosphorus Pollution Reduction Strategies”
  This webinar demonstrates EPA’s Nitrogen and Phosphorus Pollution Data Access Tool as well as the new, interactive SPARROW Decision Support System (DSS), designed by the U.S. Geological Survey.

December 23, 2011

• EPA Adds Updated SPARROW data to the Data Access Tool
  USGS recently completed syntheses of the results from 12 independently calibrated regional-scale SPARROW models that describe water quality conditions throughout Major River Basins of the conterminous U.S. based on nitrogen and phosphorus sources from 2002. Two data layers - one for nitrogen and one for phosphorus – now provide an approximate yet regionally consistent synthesis of the locations of the largest contributing sources.