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Overview of Stormwater Management Regulation in Pennsylvania
Any development activity that changes the surface features of land also affects what happens when precipitation occurs. The result can have an impact on the chemical, physical and/or biological properties of the streams, rivers, and lakes that ultimately receive the runoff. In order to protect water quality, such development activities are regulated under the federal Clean Water Act, as well as Pennsylvania’s Clean Streams Law and the Pennsylvania Storm Water Management Act.
The Pennsylvania Department of Environmental Protection (DEP) administers the Commonwealth’s stormwater management program, which requires stormwater be treated to the maximum extent practicable. Modeled after the federal National Pollutant Discharge Elimination System (NPDES) program, Pennsylvania’s program establishes permit requirements for construction sites disturbing more than one acre, industrial sites, and Municipal Separate Storm Sewer Systems (MS4s).
The Pennsylvania Storm Water Management Act of 1978 (more commonly known as Act 167) actually provides the legislative basis for statewide stormwater management. It requires that counties within designated watersheds develop stormwater management plans, and that each affected municipality adopt specific stormwater ordinances to implement their respective Act 167 plan. Pennsylvania has 2566 municipalities and 376 designated stormwater management watersheds—each with a diverse set of natural, social, and cultural features—and this unique “sharing” of power and authority between levels of government was designed to provide flexibility to address the specific characteristics of each watershed.
In 1990 federal Clean Water Act regulations established the National Pollutant Discharge Elimination System (NPDES), requiring large construction sites, certain industrial facilities, and municipalities with populations of 100,000 or more (large and medium MS4s) to obtain NPDES (Phase I) permits and develop stormwater management plans. In 1999, NPDES Phase II was signed into law to build on the initial program. While Phase I applied to construction sites affecting 5 acres or more, Phase II required all individual land development projects that disturb one acre or more to obtain permits. Phase II also required small municipalities to obtain permits for their stormwater discharges. Whether small or large construction site, industrial facility, or MS4, each permit holder must implement and enforce a stormwater management program that reduces the discharge of pollutants to the maximum extent practicable.
In Pennsylvania, most NPDES permits are administered by county conservation districts through delegation agreements with the Pennsylvania Department of Environmental Protection (DEP). Conservation districts process and authorize the permit applications, conduct site inspections, respond to complaints, and in certain circumstances, conduct enforcement actions.
In September 2002, in an attempt to integrate its various stormwater management programs and promote a comprehensive watershed approach to stormwater management, DEP finalized a Comprehensive Stormwater Management Policy, DEP Policy No. 392-0300-002. The Pennsylvania Stormwater Best Management Practices Manual was released in December 2006 to assist with the implementation of the Policy. The stated goal of the Manual is “to protect, maintain, and improve the Commonwealth’s water resources, while allowing for the continued growth and development of Pennsylvania.” The Manual describes a stormwater management approach to land development that:
- first, emphasizes reducing the impacts of development activities through planning and development techniques that avoid potential impacts to watershed resources; and
- second, minimizes and mitigates any unavoidable impacts through the use of both structural and non-structural best management practices
Pennsylvania’s Stormwater Management Standard:
- In Special Protection Waters – There should be no measurable change in post construction stormwater runoff volume, rate and quality.
- In Waters other than Special Protection – There should not be a loss of the existing use from any change in post construction stormwater runoff volume, rate and quality.
Technical information, permit applications, and the Pennsylvania Best Management Practices Manual can be found on the DEP Stormwater Management site.
