The agency's revision to its Clean Air Act "new source review" rules prompted agency enforcement managers to "drop investigations into 50 power plants for past violations," Christopher Drew and Richard A. Oppel, Jr., report. They report that enforcement lawyers for the agency told them the new less stringent rules "would make it almost impossible to sustain the investigations into the plants." An EPA official statement said it would still look at the investigations "on a case-by-case basis to determine whether it will be pursued or set aside," But Democratic and environmentalist critics and a number of states described the decision as a major reversal, and as one that a top EPA air official in congressional testimony had said would not result from the new source review rulemaking. (See http://query.nytimes.com/gst/abstract.html?res=F00714F73C5D0C758CDDA80994DB404482.)