Mapping Resources

The following is a selection of resources for those seeking more information on MS4-related mapping requirements.

MS4 Regulated Area

• eMapPA - This DEP application can be used to view urbanized area (UA) based on the 2000 and 2010 censuses along with other facilities and features. The 2020 census designated UA will be added to eMap when it is released by EPA.

• MS4 Requirements Table web-based GIS application - The MS4 GIS application provides a visual representation of the impairments that were required to be addressed in Pollutant Reduction Plans (PRPs) and TMDL Plans required during the 2018-2023 permit term, based on DEP’s 2014 Integrated Report.

• PA Urbanized Areas and MS4 Municipalities (PDF) - This map of PA shows locations of urbanized areas (2010), county boundaries, major watersheds, and MS4 municipalities with general and individual NPDES permit coverage and waivers.

• EPA Urbanized Area website - Detailed 2010 UA maps can be found on EPA’s website.

Storm Sewershed Mapping

• Pollutant Reduction Plan Mapping Basics Training - This training was developed by DEP to assist MS4 permittees with developing mapping for their PRPs and TMDL Plans.

• Model Map (PDF) - An example map developed by DEP that illustrates the detail necessary to meet the basic requirements of MCM #3 as well as the advanced requirements for PRPs, TMDL Plans and Pollutant Control Measures for the current NPDES permit term. DEP has posted instructions (PDF) on how to use the Model Map.

• MS4 Storm Sewershed/Planning Area Scenarios – The example scenarios were developed by DEP to illustrate how storm sewersheds should be delineated when an MS4 permittee is determining their regulated planning area.