Telephone: 717-632-7366          20 Wayne Avenue, Hanover, PA 17331                 Fax: 717-632-2464
HomeApplications/FormsGovernmentLegal Notices/BidsOnline PaymentResidentsSite DirectoryStormwater Management

Stormwater Management and MS4

What is Stormwater? 
Stormwater is the excess water from rain or snowmelt that the ground cannot soak up. In many parts of the Township, stormwater flows into a storm drain and then through the storm sewer system. This system of pipes and channels will eventually discharge the water into a local stream or lake. There is no treatment for stormwater - anything that goes into a storm drain will go straight to our waterways, pollutants included. 

The Township waterways are part of the Chesapeake Bay watershed via the Susquehanna River - the largest supplier of freshwater to the bay.

Stormwater Management
Smart stormwater management plays a vital role in reducing flooding, protecting infrastructure, and keeping our streams and lakes clean. As new developments, roads, and industries have gone in, much of the land in the Township has been converted to impervious surfaces.  An impervious surface is something like a parking lot, building, or road that covers the ground surface and prevents water from soaking in. The more impervious surface you have, the more stormwater runoff you have.

Decades ago, development occurred without much note to how the impacts of stormwater should be mitigated. Today, we have stringent policies on how development can proceed so that the risks of flooding and environmental degradation are reduced as much as possible.

Federal, state, and local regulations oversee the management of stormwater. The Clean Water Act of 1972 (CWA) establishes a framework for regulating pollutants discharged into waterways and is administered by the US Environmental Protection Agency (EPA). The PA Department of Environmental Protection (DEP) has been delegated to oversee some of these federal regulations, as well as to enforce the PA Clean Streams Law of 1937. Additionally, Penn Township's Stormwater Ordinance of 2011 defines the specific regulations for our municipality.

MS4 Program
In 2016, Penn Township was notified of its designation as a small MS4. MS4 stands for Municipal Separate Storm Sewer System and refers to the Township's stormwater conveyance systems. The MS4 Program is a federal program that regulates stormwater in urbanized areas. Because the population density of Penn Township has surpassed a certain threshold, the impact of our stormwater on natural systems is high enough to require regulation under the MS4 Program.

The Township received the MS4 permit in 2020. As a permittee, we are required to have a Stormwater Management Program that incorporates the following six elements:

  • Public education and outreach
  • Public involvement and participation
  • Illicit discharge detection and elimination
  • Construction site runoff control
  • Post-construction stormwater management
  • Pollution prevention and good housekeeping
To learn more about stormwater and MS4 in Penn Township, use the links to the right and across the top of this page.​
Informative Links
For questions, comments, or concerns regarding stormwater, illicit discharges, or construction runoff, call (717) 632- 7366 ext. 1145 
How can you reduce pollution?
What is MS4?
There are currently vacancies on the Penn Township Storm Water Authority Board
If you are interested in serving, please fill out the application and email to or submit it at the Municipal Building at 20 Wayne Avenue.
To report illicit discharges, please call 717-632-7366 ext. 1145, please leave your contact information and a detailed message.
Read the latest addition of THE RE-CAP, the Watershed Alliance of York's bi-monthly newsletter about the implementation of the County wide Action Plan for clean waters.