The Clean Air Act's (CAA's) new source review (NSR) program has not been effective. Some of the worst emitters of air pollutants today were among the worst polluters when control of new source emissions by the CAA began in 1970. Moreover, the program as applied to existing sources, despite its marginal successes, is characterized by uncertainty, complexity, vagueness concerning its requirements, and the potential high costs associated with unpredictable enforcement. Moreover, the discretionary power claimed by the government in the exercise of its power to implement NSR results in regulators having far more involvement in business decisionmaking than is necessary for an effective environmental protection program.

Since 1970, the U.S. Environmental Protection Agency (EPA) has been tasked with developing new source performance standards (NSPS) for industry classifications. The U.S. Congress when enacting new source requirements expected that air quality would improve as old sources were replaced by sources subject to NSPS. This did not happen. Control of existing sources usually was left to the states, and unless they were subject to CAA regulations to improve air quality in nonattainment areas (NAAs), states often imposed few controls. Today, for areas that meet national ambient air quality standards (NAAQS), controls on existing facilities are often still minimal, although, as discussed later in the Article, this is changing. The economic benefits from not having to meet CAA requirements encouraged companies to keep facilities operating beyond their originally projected useful life.