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.

July 31, 2015

• 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 2014 facility monitoring reports (previously 2013 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 2015 (previously the layers reflected May 2014 ATTAINS data).
• Updated Data on Drinking Water Sources
  The Drinking Water Sources HUC12 Density data layer now provides information on surface and ground water sources as of (quarter 4) 2014 (previously the layer reflected (quarter 3) 2010 data).

May 14, 2014

• EPA Adds American Indian Tribal Lands Boundaries to NPDAT
  American Indian Tribal Lands Boundaries have been added to the NPDAT. This layer represents locations of American Indian tribal lands in the lower 48 states. The areas include all lands associated with federally recognized tribal entities -- federally recognized reservations, off-reservation trust lands, and Census Oklahoma Tribal Statistical Areas.
• 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 February 2014 (previously the layers reflected January 2013 ATTAINS data).
• Updated Data on National Pollutant Discharge Elimination System (NPDES) Concentrated Animal Feeding Operations (CAFO) Summary
  The data layer on NPDES CAFO Summary now reflects data reported by EPA Regions as of December 31, 2012 (previously the summary reflected data reported in 2010).

September 27, 2013

• 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 2011 facility monitoring reports (previously 2010 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 January 2013 (previously the layers reflected May 2012 ATTAINS data).

October 12, 2012

• Updated Data javascript:void(0);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.