Doubts About Methods To Assess Groundwater Vulnerabilty to Virus Contamination

FOR IMMEDIATE RELEASE ACS News Service Contacts:
Print media: Jim Bohning, 202/872-6041 (office), [email protected] Broadcast media: Theresa Laranang-Mutlu, 202/872-4371 (office), [email protected] For a copy of the full article: Sally Pecor, 202/872-4451 (office), [email protected]

2/3/97#12126

News Summary

NEW RESEARCH RAISES DOUBTS ABOUT EXISTING METHODS TO ASSESS GROUNDWATER VULNERABILITY TO VIRUS CONTAMINATION

The commonly used methods for measuring the efficiency of soil to remove viruses from human waste may be providing inaccurate and misleading information about virus retention and transport in the subsurface, says Dr. Yan Jin of the University of Delaware. Her research appears in the February issue of Environmental Science & Technology, a monthly publication of the American Chemical Society.

Since 1990, the viruses from human waste have been responsible for about 70 percent of the waterborne disease outbreaks in the United States that are caused by the use of contaminated ground water. Jin says that the U.S. Environmental Protection Agency is in the process of developing a drinking water regulation that is intended to minimize the number of these outbreaks. In order to do this, Jin notes, it is necessary to understand the factors that control the movement of the viruses from waste sources such as septic tanks and leaking sewer lines to the ground water. A critical part of that evaluation is determining the extent to which the soil removes the viruses from water and renders them incapable of infecting living hosts.

Traditionally, Jin says, the degree of virus removal by soil has been determined using laboratory experiments called batch studies, which are done in test tubes. But Jin claims that her research casts doubt on the ability of these laboratory tests to provide useful information about virus removal by soil. Using soil columns instead of test tubes to simulate actual ground conditions, Jin says her results show that the interactions between viruses and soil are not consistent with those used to interpret batch experiments.

The result of a batch study, she asserts, could lead to an erroneous prediction that a site was vulnerable to virus contamination, when in reality, no such danger existed. In other cases, where water flowed more rapidly, the opposite result could occur. Jin recommends that the use of columns deserves further study because they may provide more accurate information on which to base decisions about vulnerability of ground water to virus contamination.

# # # #