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Project ID: 2004HI60B

Title: Application of Innovative Methods and Strategies to Differentiate Sewage from Non-Point Source Pollution in Hawaii

Project Type: Research

Focus Categories: Methods, Non Point Pollution, Water Quality

Keywords: Fecal Indicators, Water Quality Standards, Sewage Pollution, Non-Point Source Pollution

Start Date: 03/01/2004

End Date: 02/28/2005

Federal Funds: $18,006

Non-Federal Matching Funds: $56,843

Congressional District: First

Principal Investigator:
Roger Fujioka
University of Hawaii


The basic water quality problem in the state of Hawaii is that all streams in Hawaii consistently exceed the USEPA-recommended recreational water quality standards, which are based on concentrations of USEPA approved fecal indicator bacteria (fecal coliforms, E. coli and enterococci). The normal habitat of these fecal bacteria is the intestinal tract of humans and other mammals and when these bacteria are found in environmental waters that exceed the USEPA water quality standards, USEPA guidelines interpret these results to indicate that the environmental water is contaminated with sewage and the risk to human infection with sewage-borne pathogens is unacceptable. However, in Hawaii and Guam the USEPA-recommended fecal indicator bacteria are naturally present and multiply in the soil environment. Rain, the source of all streams in islands is the mechanism by which these soil-bound fecal indicator bacteria are transported to streams at concentrations that routinely exceed the recreational water quality standards. Thus, the source of the consistently high concentrations of fecal bacteria in the streams of Hawaii and Guam comes from soil rather than from sewage. Moreover, since these fecal bacteria multiplied under ambient soil environment and since most sewage-borne pathogens (all human enteric viruses, most protozoans, many bacteria), cannot multiply under environmental conditions, the concentrations of fecal bacteria do not carry the same risk as those proposed by USEPA. In conclusions, monitoring environmental waters for fecal indicator bacteria in Hawaii and Guam cannot be reliably used to determine when these waters are contaminated with sewage. We previously determined that monitoring environmental waters in Hawaii for C. perfringens, another fecal bacteria, can be used to reliably determine when environmental waters are contaminated with sewage. Based on ambient concentrations of recreational water quality standards were developed for fresh water streams and for coastal beach water. However, USEPA has not accepted these new standards and insist that Hawaii continue to monitor for their recommended fecal bacteria. Although monitoring for C. perfringens is reliable for most conditions, there are some conditions when it cannot be determined whether the source of contamination is human sewage (point source) or animal fecal contamination (non-point source). In this regard, no single fecal indicator is reliable under all conditions. Thus, the objective of this study is to assess the reliability of monitoring environmental waters in Hawaii for C. perfringens in combination with another alternative fecal indicator (F-RNA coliphages, sorbitol-fermenting Bifodobacter, fecal sterols) for the purpose of developing the best combination of test methods and strategy to reliably determine when any environment is contaminated with sewage or with non-human contamination.

Progress/Completion Report PDF

U.S. Department of the Interior, U.S. Geological Survey
Maintained by: John Schefter
Last Updated: Wednesday July 13, 2005 9:54 AM
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