The discharge mapping tool can help you determine:

• the receiving waters to which your facility discharges, and
• whether they are considered "impaired" under section 303(d) of the Clean Water Act.

• Additional Information About the Discharge Mapping Tool - Provides background information on the tool and further instructions for its use.

You also can use the tool to assist you in providing the required receiving waters information on your Notice of Intent (NOI) for the:

• 2022 Construction General Permit (CGP) or
• 2021 Multi-Sector General Permit (MSGP)

Using the Discharge Mapping Tool

Step 1.

Enter the location of the site/facility.

1. Enter the address or latitude/longitude of your site/facility into the "Find address or place" box.
2. Click the <enter key> or the magnifying glass icon to zoom the map to that location.

Step 2.

Draw your site/facility or discharge point locations on the map.

1. On the map, zoom in to your site/facility location.
2. Then either click the "Draw a Polygon" icon () or "Draw a Rectangle" icon () on the top right of the map, and draw an outline of your site/facility or

Click the "Draw a Point" icon () on the top right of the map and draw your site/facility's exact discharge point(s) (i.e., outfalls).

Step 3.

Click "Open Report" button below the map.

The mapping tool provides an output table that includes information about the surface waters to which you discharge, including:

• Any waters associated with the catchment ID
• Any causes of impairments and their corresponding assessment unit IDs
• Any TMDLs and their corresponding TMDL IDs, and
• Any TMDL pollutants

Note: If you selected multiple points or polygons, they all are processed when you click the "Open Report" button.

Managing Your Map

• To delete a point or polygon, select it and click on the trash can icon () at the top right of the map.
• To remove all points and polygons, click the "Clear All Graphics" button underneath the map.
• To edit or move a point or polygon, just click it to select it and then use the handles to modify its location or shape.
• To save the map, click Save Map for Later to create a unique link that you can bookmark or share with others that contains all the points and polygons that were entered. Upon navigating to that link, the points and polygons will populate automatically on the map.

For questions or comments about the tool, email cgp@epa.gov.