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LETTERS Water regulation cost Dear Sir: The need for economic impact statements as a part of the process leading to new or amended regulations is essentially recognized universally. However, it is also necessary to make the economic analysis realistic. In the case study presented in this article there are several factors that tend to inflate the final analysis ( E S & T ,June 1979, p 656). In the first instance, the selection of discharges was based upon an inadequate data base. In many cases the decision was based on the results of less than one sample per year without any consideration of the trend. Starting in 1969, there was a major effort nationwide to reduce mercury discharges to the absolute minimum. Thus, dis-
charges with effluent mercury concentrations greater than 0.5 p g / L in 1977 would be much more suspect than a discharge that exceeded the effluent standard in 1972 but never since. The result was the inclusion of some discharges that most probably were not violating the standard. The major failing though is the assumption that all discharges in violation of the mercury effluent standard (0.5 pg/L to 3.0 p g / L ) would have to provide a mercury removal process (ion exchange being cited) to achieve the standard. This is unrealistic since the dischargers would probably first initiate sampling programs (at some cost) to determine if they were still in violation. If violations still existed, then an evaluation of the source of the
mercury and possible corrective measures would be done. This could be anything from replacing the leaking seal on a trickling filter to cleaning sink traps and dilution chambers to changing to an alternative industrial process. The point is that. in most instances, the final decision (based on economics) would not have been to build a waste treatment system but rather to first find the mercury source and eliminate or reduce it as much as possible. Thus, the net result is an economic analysis that shows unrealistically high treatment costs and higher savings than achievable by changing the effluent standard. Fortunately, it is of no major consequence in this case since the environmental consequences of changing the mercurj effluent standard from 0.5 to 3.0 p g / L are negligible, but I can visualize similar applications where the erroneous use of the assumption that the only solution is additional waste treatment could make a regulation that is environmentally beneficial appear to be economically unsound. As in all cases, when one is forced to do an analysis with a paucity of data in a minimum of time, the results are most often unsatisfactory. C. M. Timm 18 a rte de Drize
1227 Carouge G E Switzerland
Environmental research journals Dear Sir: Studies of journal citation frequencies are always good fun with a computer, and the one on Journal Citation Frequency by Subramanyam and O’Pecko ( E S &T, 13, 927 ( 1 979) is no exception. On the other hand, like other studies of citation frequencies, it has limitations beyond the ones cited in the paper. The chief one is that it is an almost universal finding that, just as authors tend to cite their own work, authors publishing in a given journal tend to cite papers in that journal. Thus, I am quite sure that, for example, a similar study of Atmospheric Encironment would show a predominance of citaCIRCLE 11 ON READER SERVICE CARD
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Environmental Science & Technology
