||20 THE THIRTY-SIXTH ANNUAL REYNOLDS LECTURE but for various reasons, the cleanest cement plants were doing a better job than the cleanest power plants. Thus, using the scheme of basing the standard for each industry on "... best system ... [which] ... has been adequately demonstrated," EPA enacted a more stringent standard for cement plants than for power plants. The cement industry is challenging this in court. Aside from the legal question, there is an obvious moral question: should the fact that one industry has in the past done a better job than another allow the less diligent of the two to persist in its less diligent ways; or should both be required to meet a common standard? An additional problem arose in the meetings with the representatives of the petroleum industry, in the planning of standards for them. In Los Angeles, the regulations enacted in the 1950's and the 1960's for the control of hydrocarbon emissions were mostly of the prescriptive kind, i.e., if you store gasoline, you must use a certain kind of tank to store it in. In preparing its standards, EPA considered the question, "Should we have a true performance standard?" one which says, "You shall not emit more than so much; how you do it is up to you." At these meetings, the oil company representatives were unanimous in their belief that the performance standard was the philosophically sound way to proceed. It opens the door for technological innovations and clears the way for the inventive genius of the American free enterprise system to find better ways in which they can meet the standards. BUT, in this particular case why not stick with the tried and true prescriptive standard, with which they all know how to live? The law really says you should issue performance standards, and let industry find the best way to meet them. The industrial pressure has been so great, it seems clear that we will have many prescriptive standards, which tell the industry to continue doing what it has been doing. Non-Degradation Simultaneous with these attacks by industry, suggesting that the standards it was setting were too stringent, the EPA found itself sued by a group of conservation organizations, of which the Sierra Club received the most public credit for the suit. These conservation organizations pointed out that the Clean Air Act specifically states that its purpose is to ". . . protect and enhance the quality of the Nation's air . . ." and that the EPA regulations announcing the standards (i.e., permissible levels of air pollution) state that the issuance of such standards "... shall not be considered in any manner to allow significant deterioration of existing air quality in any portion of any state." The conservationists refer to this as a "non-degradation policy." This policy was formulated to prevent the solution of one area's pollution problem by exporting the pollutants to another, unpolluted area.