The stormwater requirements of the federal Clean Water Act are administered under the Pennsylvania Department of Environmental Protection's (DEP) Municipal Separate Storm Sewer System (MS4) Program. In December 2002, DEP issued a General Permit (PAG-13) for use by MS4s that fall under the National Pollutant Discharge Elimination System (NPDES) Phase II program, requiring the implementation of a stormwater management program for minimizing the impacts from runoff.
Lower Macungie Township holds an Individual Permit; individual NPDES permits must be submitted by a small MS4 when the MS4 does not meet one or more of the eligibility criteria of the PAG-13 General Permit. The Individual Permit carries the same general parameters as the General Permit, but with different timeline requirements.
Under the MS4 Program, permittees are required to incorporate the following six elements (known as minimum control measures, or MCMs) into their stormwater management programs:
- MCM 1: Public Education and Outreach on Stormwater Impacts
- MCM 2: Public Involvement and Participation
- MCM 3: Illicit Discharge Detection and Elimination
- MCM 4: Construction Site Runoff Control
- MCM 5: Post-Construction Stormwater Management in New Development and Redevelopment
- MCM 6: Pollution Prevention and Good Housekeeping for Municipal Operations and Maintenance
Minimum Control Measures
MCM 1: Public Education & Outreach on Stormwater Impacts
MCM 1 requires the permittee to develop, implement and maintain a written Public Education and Outreach Program. The purpose of the program is to educate residents, property owners, businesses, developers, and municipal staff through:
- Public meetings
- Municipality-hosted events
- Storm drain stencilings
- Employee trainings
- The township webpage dedicated to stormwater management
The goal of the program is to increase the awareness of stormwater impacts and management and to prevent or reduce stormwater pollution.
MCM 2: Public Involvement & Participation
MCM 2 requires the permittee to develop, implement and maintain a written Public Involvement and Participation Program. The primary purpose of this program is to regularly solicit public involvement from the target audience groups using available distribution and outreach methods. The solicitation of public involvement also includes advertising ordinances, standards operating procedures (SOPs), and Pollutant Reduction Plans (PRPs) for public comment.
MCM 3: Illicit Discharge Detection & Elimination
MCM 3 requires the permittee to develop and implement a written program for the detection, elimination, and prevention of illicit discharges into the storm sewer system. As a key component of this program, the township is required to maintain a map that details the location of storm sewer infrastructure as well as outfalls (i.e. the point of discharge from the storm sewer system to surface waters). Some other items that are mapped include:
- Catch basins
- Dry or wet ponds
Over the course of a permit cycle, the township must conduct dry weather screenings of all MS4 outfalls in order to evaluate the presence of illicit discharges. The program prohibits non-stormwater discharges from entering the storm sewer system.
MCM 4: Construction Site Runoff Control
MCM 4 prevents the municipality from issuing a building permit, or any other permit or final approval, to those proposing or conducting earth disturbance activities requiring an NPDES permit unless the party proposing the earth disturbance has valid NPDES permit coverage. The township must enact, implement, and enforce an ordinance or standard operating procedure (SOP) to require the implementation and maintenance of erosion and sediment (E&S) control best management practices (BMPs), including sanctions for non-compliance.
E&S control plans must be reviewed in order to ensure that the plans adequately consider water quality impacts and meet regulatory requirements. Inspections must be conducted in order to ensure the proper installation and maintenance of E&S control measures. If E&S control measures are not compliant with regulatory requirements, the township and/or Conservation District is required to impose enforcement actions.
The township is required to develop and implement requirements construction site operators in order to control waste that may cause adverse impacts to water quality.
MCM 5: Post-Construction Stormwater Management in New Construction & Redevelopment
MCM 5 requires the municipality to enact, implement and enforce an ordinance or standard operating procedure (SOP) to require post-construction stormwater management from new development and redevelopment projects, including sanctions for non-compliance. It is the township's responsibility to ensure the adequate operations and maintenance of all post-construction stormwater management best management practices (BMPs). A post-construction stormwater management (PCSM) BMP inventory shall be maintained by the municipality.
BMPs are structural, vegetative or managerial practices used to treat, prevent or reduce water pollution (e.g. swales, catch basins, channels, detention/retention basins).
MCM 6: Pollution Prevention & Good Housekeeping for Municipal Operations & Maintenance
MCM 6 requires the permittee to develop, implement and maintain a written operations and maintenance (O&M) plan for all operations that could contribute to the discharge of pollutants from the MS4. The township must identify and document all operations that are owned or operated by the permittee and have the potential for generating pollution in stormwater runoff to the MS4.
In order to prevent or reduce the discharge of pollutants from municipal operations, the township must maintain an employee training program that addresses appropriate topics to further the goal of preventing or reducing the discharge of pollutants.