This map shows municipal, industrial, and commercial facilities that have been issued permits to discharge wastewater under the Clean Water Act. Section 401 of the Clean Water Act established the National Pollutant Discharge Elimination System (NPDES), which authorizes the Environmental Protection Agency (EPA) and delegated states to issue these permits to facilities that discharge wastewater directly from a pipe, ditch, or channel.

Users can click on a watershed to zoom in to areas with these facilities. Clicking on a facility reveals information about when a permit was issued and expired, and the volume of water that the facility is permitted to discharge.

Purple lines on the map indicate the boundaries of watersheds and nested subwatersheds based on Hydrologic Unit Codes (HUC).

Data Considerations

The facilities shown in this map are from a data service (last updated in May 2015) hosted by EPA. Detailed facility reports are linked from the dataset and direct users to an online EPA database providing information about each facility. Users must zoom to a scale of 1:288,895 in order to view facilities.

Data on nested watershed boundaries are from the Natural Resources Conservation Service (NRCS). Depending on the scale at which the map is viewed, the map shows 6-, 8-, 10-, or 12-digit HUC boundaries. Labels with watershed names appear only at the 6-digit level. The watersheds data layer is a tile cache that is visible only at scales smaller than 1:144,448.


The data will be updated as EPA pushes out changes to its web services.