BOX 1-1
Overview of the Clean Water Act

The federal Clean Water Act (33 USCA sec. 1251, et seq., referred to as the CWA in this report) provides the basic legal framework for safeguarding and restoring the quality of the nation’s surface waters. The law originated in the Federal Water Pollution Control Act of 1948 as significantly expanded in the 1972 Water Quality Amendments and some 35 other amendments through 2000, and is of central importance to this report. The overall goal of the CWA in its many subprograms is to protect, restore, and enhance the “waters of the United States” (including but not limited to “navigable waters”; see more below) for the protection and propagation of fish and aquatic life and wildlife, recreational purposes, and the withdrawal of water for public water supply, agricultural, industrial and other purposes.

Among its diverse and complex provisions, the CWA authorizes the U.S. Environmental Protection Agency (EPA) to establish ambient water quality standards1 and limits for specific classes of pollutants. The CWA also established the National Pollutant Discharge Elimination System (NPDES),2 which regulates major industrial and sewage treatment plant discharges into the waters of the United States. Combined sewer overflows such as those in the Pittsburgh region are eligible for permits subject to various requirements to limit their environmental impacts on receiving waters, while sanitary sewer overflows are illegal. Section 404 of the CWA requires the U.S. Army Corps of Engineers to regulate public and private activities involving “dredge and fill” of navigable waters pursuant to environmental guidelines issued by EPA. Under judicial and administrative interpretation, this section underlies federal regulation of wetlands throughout the United States in conjunction with state and local wetland management programs.

Under Section 303(d) of the CWA, states and authorized tribes are required to identify surface waters that are “impaired” by pollution sources, including failing septic systems, acid mine drainage, and agricultural runoff. To remediate these ambient water quality problems, states must prepare “total maximum daily load” (TMDL) plans under which the relevant pollutants are reduced through a range of measures including “best management practices” (BMPs).

Ultimately, authority for implementation and enforcement of the CWA rests with the EPA. However, the Pennsylvania Department of Environmental Protection (PADEP) is a key partner in this process at the state level, while the Allegheny County Health Department (ACHD) exercises concurrent jurisdiction with PADEP over sewage and discharges of wastewater within Allegheny County.


Ambient water quality standards (AWQSs) are determined by each state and consist of (1) designated beneficial uses (e.g., drinking water supply, primary contact recreation); (2) narrative and numeric criteria for biological, chemical, and physical parameters to meet designated use(s); (3) antidegradation policies to protect existing uses; and (4) general policies addressing implementation issues. State water quality standards have become the centerpiece around which most surface water quality programs revolve; for example, they serve as the benchmark for which monitoring data are compared to assess the health of waters and to list impaired waters under CWA Section 303(d) (AWQSs are discussed extensively in Chapter 3).


As authorized under Section 402 of the CWA, the NPDES permitting program controls water pollution by regulating point sources (e.g., discrete conveyances such as pipes) that discharge pollutants into waters of the United States (see Chapter 3 for further information).

conditions. Furthermore, many older homes in rural areas and former coal mining towns discharge sewage directly into local streams via straight pipes and “wildcat sewers” (see Appendix C for various sewage disposal and other terms used throughout this report).

The diverse water and sewage problems of southwestern Pennsylvania are often linked hydrologically. A downstream community’s poor water quality problem may result from an upstream community’s overflowing sewers, straight pipes, or failing septic systems. Whereas some municipalities have taken steps to address their water and sewage problems, many others face major water quality problems. Individual efforts may bring about limited improvements but

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