Over the last several months, under pressureof court-ordered deadlines, the Environmental Protection Agency (EPA) has been promulgating long overdue Clean Water Act best available technology (BAT) standards for toxic pollutants. In the final BAT effluent limitations guide-lines BAT often is the same as the best practicable technology (BPT). Where the new BAT is more stringent than BPT, the difference is relatively small and potentially more effective technologies were rejected. On the other hand, some BPT standards in the new rules are based on control technologies too advanced to have been considered "practicable" in 1972. It can be argued that EPA has coupled relatively tough BPT with relatively lenient BAT.

The new BAT rules raise several questions. Answering those questions requires detailed familiarity with the technological and economic data and analysis in the development documents used by EPA in setting the standards; as well as careful weighing of ambiguous statutory language, lengthy legislative history, and a variety of relevant, but not dispositive precedent. Final answers (mercifully) may be left to others, but a review of the Federal Register notices suggests that two questions should be addressed: