LETTERS Dredging Dear Sir: The April issue of €S&T contained three articles (pp 326-338) on dredged material regulation and research. In view of the National Wildlife Federation’s considerable interest in this subject, we are moved to offer the following comments. The articles by Lee and Smith point up one of the biggest problems in disposing of dredged material in a way that satisfies legal requirements and environmental protection concerns. As Lee indicates, “what is needed is a procedure by which the potential significance of chemical contaminants in dredged sediments can be assessed prior to dredged material disposal.” Implications for both water quality and ecological and biological integrity need to be evaluated. Yet, the existing EPA guidelines under section 404 of P.L. 92-500 and the ocean dumping criteria under P.L. 92-532 fall far short of prescribing procedures for assuring that these environmental implications are addressed, much less addressed adequately. Thus, an “elutriate” test is provided for which, at most, tells one how
much of various “major constituents” will be released from the dredge spoil into the water column over the relatively short term. As Smith notes, ”benthic species can ingest contaminated sediment particles,” and can become contaminated or poisoned without any escape of major constituents into the water at all. Furthermore, it is now well known that certain heavy metals (e.g., mercury, arsenic, lead, selenium, and tin) can be methylated into more soluble and more toxic forms in the environment as a result of biological activity. Such transformations would never be detected in any elutriate analysis. To add insult to injury, dredged or fill material may be excluded from even elutriate procedures if certain less-exacting qualitative requirements have been met. To be sure, the kinds of bioassay and other characterization procedures necessary to adequately evaluate environmental consequences of dredge disposal often lie near the limits of the present state-of-the-art. However, there are “worst-case” assumptions that can be made to assure necessary protection to the environment. When the state-of-theart improves, case-by-case evaluations
CIRCLE 25 ON READER SERVICE CARD
846
Environmental Science & Technology
may be more reliable and disposal restrictions can perhaps be lightened. The reverse approach-of applying loose restrictions until and unless state-of-theart improvements indicate otherwisewill not protect the environment and is contrary to the law of the land. We cannot agree with Lee that more field studies are the answer, at least for the foreseeable future. As was noted recently by a British scientist (New Scientist, April 29, 1976, pp 219-221): “Present survey strategies appear to be based on such inadequate theoretical frameworks that they cannot possibly interpret subtle environmental changes. An understanding of these effects will require detailed study of biological interactionsover many years. Short-term, on-off “impact” statements or “base-line surveys” cannot be expected to provide an adequate framework for monitoring environmental changes.” We’d prefer to place our trust for the interim in laboratory and in situ bioassays, coupled with a healthy dash of respect for basic ecological principles. Kenneth S. Kamlet, Counsel National Wildlife Federation Washington, D.C. 20036
Groundwater Dear Sir: I read with much interest and great disappointment the article “Quality Assurance for Groundwater” ( E S T , March 1976, p 226). My interest in groundwater protection parallels much of what was expressed throughout the first half of the article. Certainly, groundwaters that lend themselves for public use need to be protected from pollutants and contaminants that may threaten human health. However, in the latter half of the article mention is made of human and animal wastes, and enteric viruses from human wastes being detected in groundwater supplies. Additionally, it was noted that “the major source of these viruses turned out to be leachates from sanitary landfills in which many disposable diapers containing untreated fecal matter had been buried”. There is much confusion and misunderstanding regarding land disposal sites. Unfortunately, many individuals fail to distinguish among the types of waste disposal sites-for example, dump, covered landfills, and engineered sanitary landfills. My disappointment and alarm stems from the fact that the author himself or the spokesman from the EPA Office of Water Supply implies that the disposable diapers containing untreated fecal matter gave rise to enteric viruses that resulted from leachates generated in a sanitary landfill site-with emphasis on the term “sanitary”. I question whether the site was indeed a sanitary landfill site or whether it was an improperly operated waste disposal site. In the absence of clarification and with the emphasis on “sanitary” it almost seems as if the author is taking a “cheap shot” at sanitary landfilling-a necessary approach for effectively managing our discards. NSWMA as the professional trade as-
