Cornell Chronicle (10/21/93): Bioremediation May Be Key for Pollution Cleanup By William Holder Cleanup of polluted soil and ground water throughout the United States will require extensive use of bioremediation, because in many instances conventional technologies are ineffective or cost-prohibitive, according to a Cornell researcher. Yet bioremediation technologies - which use microorganisms to detoxify pollutants - require more policing of their use, said Eugene Madsen, assistant professor in microbiology at Cornell. Madsen, who teaches environmental microbiology here, participated in a study of bioremediation organized by the Water Science and Technology Board of the National Research Council, whose findings were released Sept. 24. The committee's report, drafted by Madsen and others, pointed out that there are "almost no sites where polluted ground water has been restored to a condition fit for drinking" with conventional pump-and-treat technologies. Efforts to clean soil have been somewhat more successful, but technologies used to decontaminate soils often expose cleanup crews or nearby residents to contaminants. Bioremediation in situ treats contaminants where they are found - in the soil and ground water. Proponents argue that this approach is less costly, faster and safer, yet the NRC committee acknowledged that "bioremediation is neither universally understood nor trusted by those who must approve its use. "Bioremediation is clouded by controversy over what it does and how well it works, partly because it relies on microorganisms, which cannot be seen, and partly because it has become attractive for 'snake-oil salesmen,' who claim to be able to solve all types of contamination problems," the report stated. Said Madsen, "The industry is not mature enough to be self-policing. Some companies promise more than can be delivered and rely on wishful thinking instead of sound scientific information." Bioremediation has, nonetheless, scored some notable successes during the past decade. Long known as an effective means for treating petroleum spills, microorganisms have been shown to be capable of detoxifying such important pollutants as PCBs (polychlorinated biphenyls) and other chlorinated compounds, including the common industrial solvent trichloroethylene. "These are compounds that were once thought to be completely resistant to microbial metabolism," Madsen said. The NRC report, titled "In Situ Bioremediation: When Does It Work?" is intended to set standards for evaluating the use of bioremediation in the field, according to Madsen. Practitioners face serious problems in proving that bioremediation works in very complicated field conditions. Pollutants underground are difficult to measure and can be dissipated through a variety of non-biological processes. Furthermore, the results of laboratory biodegradation tests can seldom, if ever, be extrapolated to field sites. .