NPDES for MS4s

The National Pollutant Discharge Elimination System (NPDES) regulations for municipal separate storm sewer systems are federal regulations administered nationwide by the Environmental Protection Agency. Phase I of the program was applicable to large municipal separate storm sewer systems. Under Phase II of this program, regulations are applicable to small municipal separate storm sewer systems (MS4s).

The goal of this program is to limit the amount of pollutants entering our streams and lakes through separate storm sewer systems. A separate storm sewer system is a stormwater collection and conveyance system (inlets, piping, swales, gutters, detention ponds, outlets, BMPs) that is intended to carry only stormwater runoff. Separate storm sewer systems are not combined with sanitary sewer systems and generally discharge directly to a stream. The MS4 program requires regulated municipalities to develop and implement a stormwater management program that addresses six Minimum Control Measures (MCMs) for municipally owned or operated systems. The MCMs are:

1. Public Education
2. Public Participation
3. Illicit Discharge Detection and Elimination
4. Construction Site Stormwater Management
5. Post-Construction Stormwater Management
6. Pollution Prevention and Good Housekeeping at Municipal Facilities

In Pennsylvania, the MS4 program is administered by DEP. The Dauphin County Commissioners designated DCCD as the agency responsible for ensuring that the county is in compliance with the terms of its permit. The Conservation District has developed a plan to meet the six requirements listed above (Click here to see the plan). Public input on the plan is welcomed. Written comments may be emailed to Bob Christoff at rchristoff@dauphinc.org.

For more information on the Act 167 and NPDES MS4 programs, click here for the DEP website and type "stormwater" as the keyword.

Click here for an Adobe PDF file of Dauphin County's MS4 implementation plan.

National Pollutant Discharge Elimination System (NPDES)
Regulations for Municipal Separate Storm Sewer Systems (MS4s)