EPA hygienic water quality standards are applied equally to every state, without regard to differences in the environment of each state. In this regard, Hawaii is the only state located in the tropical region of the world and comprised of islands. A major challenge facing the state of Hawaii is that as a result of its tropical climate, all streams greatly exceed EPA recreational water quality standards based on concentrations of 200 fecal coliform/100 ml, 126 E. coli/100 ml or 33 enterococci/100 ml. Coastal waters which receive land-based run-off such as streams and storm drains often exceed marine recreational water quality standards. In the interpretation of recreational water quality standards, EPA assumes that sewage and feces from mammals are the only significant sources of fecal bacteria and environmental waters that exceed water quality standards are contaminated with fecal waste and the risk for presence of sewage-borne pathogens is unacceptable. However, we have shown that the EPA-approved fecal indicator bacteria are able to multiply in the soil environment of Hawaii and have become established as populations of soil bacteria. The consistently high concentrations of fecal bacteria in Hawaii’s streams represent contamination with soil rather than sewage. Thus the concentrations of these fecal bacteria in Hawaii’s streams are not related to the degree of sewage contamination and probability for presence of most sewage-borne pathogens (human enteric viruses, protozoa), which cannot multiply in the environment. However, based on EPA water quality guidelines, it must be concluded that Hawaii streams and many coastal water sites are contaminated with sewage and action should be taken to reduce the concentrations of these fecal bacteria in environmental waters. EPA’s water quality standards are not applicable for Hawaii because these standards were based on data obtained from temperate region of the world and the basic principle of microbial ecology (microbial process and microbial populations are controlled by the environment) was ignored. The principle of microbial ecology also explains why water-borne infections of leptospira and Staphylococcus aureus are highest in the state of Hawaii and why vibrio bacteria are present in coastal waters throughout the year as compared to only summer months in temperate climates. As a result, the strategy to develop water quality guidelines and standards in Hawaii requires greater understanding of microbial ecology and monitoring for other indicators of fecal contamination such as Clostridium perfringens, FRNA coliphages, Bifidobacter, Bacteroides by PCR and fecal sterols. Moreover, environmental waters in Hawaii must be monitored for pathogenic leptospira, S. aureus, and Vibrio spp. EPA has not developed water quality standards and do not require monitoring for these water-borne pathogens.
Presenter:
Roger Fujioka, Ph.D.
Researcher
Water Resources Research Center
University of Hawaii
Friday July 2, 2004
11:00 a.m.
Marine Sciences Building, 114
The Pacific Research Center for Marine Biomedicine (PRCMB) is a newly established center at the University of Hawaii dedicated to trans-disciplinary research designed to gain new knowledge about the profound impacts of the ocean on human health. The Center is funded by the National Science Foundation and the National Institute of Environmental Health Sciences.
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