Stormwater Management

UNION TOWNSHIP - Washington County, Pennsylvania


June 2023

Union Township owns and operates Municipal Separate Storm Sewer Systems (MS4s) in portions of the Township that are considered urbanized by the United States Environmental Protection Agency (EPA).

What Is an MS4?

MS4s are conveyances or systems of conveyances including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains that are owned or operated by a public entity, are designed or used for collecting or conveying stormwater, and are not a combined sewer or part of a publicly owned treatment works.

A municipality is bound by EPA regulations for an MS4 when all or a portion of a municipality lies within an urbanized area, as determined by the US Census Bureau.

Stormwater regulations associated with the Federal Clean Water Act are administered under the MS4 Program by the EPA. In Pennsylvania, the MS4 program is managed by the Pennsylvania Department of Environmental Protection (DEP) on behalf of the EPA. The DEP Permit provides a streamlined process to meet the state and federal stormwater requirements. Operators of a regulated MS4 must obtain a National Pollutant Discharge Elimination System (NPDES) permit and develop and implement a stormwater management program according to the details of their specific permit. Mandatory elements of the stormwater management program include six Minimum Control Measures; each Minimum Control Measure has various associated Best Management Practices.

Why Do We Regulate Stormwater?

The MS4 program requires the MS4 owner/operator to implement a series of control measures to reduce the discharge of pollutants from the storm sewer system to the maximum extent practicable in a manner that protects water quality. The Pennsylvania Code Chapter 93 sets the water quality standards for surface waters of the Commonwealth and these standards seek to protect the waters for aquatic life, water supply, recreation and fish consumption. Chapter 93 also establishes areas that require special protection. The MS4 program focuses on managing stormwater discharges into the waters of the Commonwealth by educating the community and by implementing proper control measures and best management practices.

Each MS4 permittee must create a Stormwater Management Program to minimize the impacts from runoff. A Stormwater Management Program must be completed to comply with the NPDES MS4 Permit. The Stormwater Management Program requires municipalities to focus on six Minimum Control Measures (MCM) listed herein.

MCM 1: Public Education and Outreach Program (PEOP)

The goal of the Public Education and Outreach Program MCM is to build greater support for the stormwater management program, increase compliance, and ultimately increase environmental awareness amongst members of the community.

This MCM includes distributing educational materials and performing outreach to inform the public about the impacts polluted stormwater runoff discharges can have on water quality.

MCM 2: Public Involvement and Participation Program (PIPP)

The goal of the Public Involvement and Participation Program MCM is to facilitate successful implementation of your Stormwater Management Program through a number of means, including: garnering broad public support; utilizing expertise and local knowledge; shortening implementation schedules; and building partnerships with other community and government programs.

This MCM includes providing opportunities for the public to participate in program development and implementation, including effectively publicizing public hearings and/or encouraging participation in implementing the stormwater management program.

MCM 3: Illicit Discharge Detection and Elimination (IDD&E)

The goal of the Illicit Discharge Detection and Elimination MCM is to reduce pollution to our waterways through the removal of non-stormwater contributions to the storm sewer system. Common sources of illicit discharges include sanitary wastewater, improper disposal of auto and household toxins, and car wash wastewaters.

This MCM includes developing and implementing a plan to detect and eliminate illicit discharges to the storm sewer system, including developing a system map and informing the community about hazards associated with illegal discharges and improper disposal of waste and encouraging citizens to notify the Township of potential illicit discharges.

Union Township conducts annual inspections of each known MS4 outfall each year to identify potential illicit discharges but encourages citizens to report any suspected illicit discharges as soon as possible.

To assist citizens in the task of notifying the Township of potential illicit discharges, a Illicit Discharge Reporting Form has been included in this mailer and is available online. To find the form online, please visit the Union Township Website’s Stormwater Management page.

Forms should be mailed or delivered to the Union Township Municipal Building located at 3904 Finleyville-Elrama Road, Finleyville, PA 15332.

MCM 4: Construction Site Stormwater Runoff Control

The goal of the Construction Site Stormwater Runoff Control MCM is to protect our waterways from stormwater-related pollution that can result from construction activities.

This MCM includes developing, implementing and enforcing an erosion and sediment control program for construction activities that disturb the land surface.

MCM 5: Post-Construction Stormwater Management (PCSM) in New Development and Redevelopment Activities

The goal of the Post-Construction Stormwater Management in New Development and Redevelopment Activities MCM is to avoid increased stormwater runoff problems and increased non-point source pollution that often accompanies the development of land and associated increase in impervious surfaces.

This MCM includes developing, implementing and enforcing a Stormwater Management Ordinance and program to address discharges of post-construction stormwater runoff from new development and redevelopment areas. Applicable controls could include preventative actions such as protecting sensitive areas such as wetlands and streams and the use of structural BMPs such as grassed swales or porous pavement.

MCM 6: Pollution Prevention/Good Housekeeping

The goal of the Pollution Prevention/Good Housekeeping MCM is to help ensure a reduction in the amount and type of pollution that is generated from municipally owned and maintained facilities (e.g., streets, parking lots, and vehicle maintenance areas) and eventually discharged into local waterways. An additional goal of MCM #6 is to reduce the amount of pollution that is discharged to waterways from poor maintenance of storm sewer systems.

This MCM includes developing and implementing a program to prevent or reduce pollutant runoff from municipal operations. The program includes municipal staff training on pollution prevention measures and techniques of street sweeping, reduction in the use of pesticides or street salt, or frequent catch-basin cleaning.