William & Mary Environmental Law and Policy Review
Abstract
This article provides a comprehensive overview of how environmental quality standards for air and water are created, implemented, and enforced in the United States, with a focus on the interplay between federal and state authority. It examines the distinct regulatory frameworks established under the Clean Water Act (CWA) and Clean Air Act (CAA), highlighting the statutory mandates, administrative structures, and enforcement mechanisms governing ambient quality standards.
For water quality, the authors detail the development of state water quality standards (WQS), the National Pollutant Discharge Elimination System (NPDES) permitting program, and the Total Maximum Daily Load (TMDL) process, as well as antidegradation policies and nonpoint source management strategies. For air quality, the discussion centers on the creation and periodic review of National Ambient Air Quality Standards (NAAQS), State Implementation Plans (SIPs), the Prevention of Significant Deterioration (PSD) program, and compliance measures for attainment and nonattainment areas.
The article emphasizes the cooperative federalism model underlying both statutes, the challenges posed by scientific and technological constraints, and the divergent regulatory approaches: under the CAA, the EPA sets national ambient pollution limits with states responsible for implementation, while under the CWA, the EPA sets technology-based industry standards and states define acceptable ambient pollution levels. This primer serves as a reference for environmental law educators, practitioners, and policymakers—domestically and internationally—seeking insight into U.S. environmental quality standard-setting and its potential comparative applications.