The Environmental Protection Agency's (EPA's) efforts to implement provisions of the 1977 Clean Air Act Amendments aimed at preventing the significant deterioration (PSD) of air quality in clean air areas of the nation have quickly become the subject of a number of lawsuits. The first set of issues in this groundswell of litigation involves the date upon which the new PSD preconstruction review requirements contained in §165 of the amended Act became effective.¹ Adopting a controversial interpretation of the statute, EPA has determined that §165 did not become immediately effective when the amendments were signed into law on August 7, 1977. Instead, the agency has decided, the review requirements in the amendments will apply only to facilities that did not obtain PSD construction permits under the preexisting EPA regulations before March 1, 1978, or upon which construction does not commence prior to March 19, 1979.

Several environmental groups have challenged EPA's timing decision, charging that it flies in the face of the express language of §165(a) and will allow more than 100 new major industrial facilities to be constructed in clean air areas without complying with the strict new preconstruction review safeguards of the 1977 Amendments. The result, they assert, will be a greater level of emissions from particular plants in many PSD areas than would be allowed under the current statutory provisions, and a consequent lessening of the potential for future industrial growth in these areas as the maximum ambient pollution levels allowable under the Act are approached at an accelerated rate. Industrial parties, on the other hand, generally agree with EPA's assessment that immediate application of §165 was not statutorily required and would have produced highly disruptive economic effects. Judicial resolution of this dispute will involve an analysis of apparently inconsistent statutory provisions and a synthesis of contrary indications of intent in the legislative history of the 1977 Amendments. It will also undoubtedly include at least some tacit assessment and balancing of the practical environmental and economic effects of immediate as compared to delayed application of the new preconstruction review rquirements of §165.