This is an opinion letter in response to a recently published Hawaii Department of Health report on May 22 (“Mahaulepu and Waikomo Watersheds PhyloChip Source Tracking Study, Hawaii”) and associated The Garden Island article (“Study clears water for swimmers”) published on June 6 of this year.
The Hawaii Department of Health (HDOH) report makes several claims and draws conclusions that contradict the actual results of the source tracking study. It is my role as the scientist now leading the Surfrider Foundation’s Kauai Blue Water Task Force (BWTF) that I am providing this letter.
The Surfrider Foundation’s BWTF shares the same goals as the HDOH in keeping the community informed on the levels of pollution in our watersheds and to protect the public from unnecessary exposure to potentially harmful pathogens that can make swimmers sick. Because of this, I have grave concern and confusion over the very strong assertions made by the HDOH from the data presented in the final report for the PhyloChip Source Tracking Study conducted in the Mahaulepu and Waikomo Watersheds. The HDOH claims that the water in Mahaulepu is “safe” for human exposure despite inconsistent and conflicting data generated by the study and presented in the report.
While a more in-depth response to the HDOH and EPA is forthcoming, here are some concerns that the Surfrider Foundation has with this study and report. The stated goal of the study was to measure the influence of human, animal, and environmental sources of fecal indicator bacteria on water quality in both the Mahaulepu and Waikomo watersheds. However, the results of the study were inconsistent and did not verify any one source that could be attributed to the majority of the bacteria measured in water samples collected from the Waiopili Stream.
In their press release the HDOH asserted that neither human or animal waste was responsible for the bacteria measured in the stream and point instead to ‘natural’ sources such as stream sediment, soil and marine plants as the source of the bacteria. However, both human and animal sources were identified as contributing to the bacteria measured in several of the tested samples. Despite the conflicting data, the report concluded that “High concentrations of FIB (Fecal Indicating Bacteria) in both Waiopili Ditch and Waikomo Stream were not caused by human or animal fecal contamination.”
This statement is simply not supported by the actual results of the study. The conclusions made in the report that exonerate human sources from contributing to the fecal indicating bacteria in the Mahaulepu watershed should be rescinded, as should HDOH’s assertion that the bacteria are from natural sources that do not pose a human health risk. The study’s analysis of the sediment samples from the stream did not match the bacteria found in the stream water (the most likely ‘natural’ source of bacteria to consider), and samples of soil throughout the watershed were not tested. The assertion by the HDOH that the observed bacteria in the stream was from natural sources contradicts the results of the study.
Most importantly, the HDOH study did not look at the presence of disease-causing bacteria or viruses in the water. The HDOH proclamation that the tested watershed, or our other waterways, are “clean” is simply false. Moreover, fecal indicating bacteria, like those tested in the HDOH study, are themselves opportunistic pathogens and can present health risks on their own. It is alarming to me that fully two-thirds of the waterways tested by Surfrider’s BWTF on Kauai are chronically contaminated with fecal indicating bacteria, testing at levels that far exceed the US Environmental Protection Agency’s standard for what is considered to be “safe” for swimming. It is true that testing for fecal indicating bacteria is not perfect, and there is always some estimation involved in determining potential health risks. But the association between high levels of fecal indicating bacteria and the presence of other pathogens has been repeatedly reported in numerous scientific and epidemiological studies worldwide, and this relationship has likewise been proven here in Hawaii as well. It is also important to note that testing for fecal indicating bacteria is the standard, as defined by the EPA, for monitoring water quality to protect public health in recreational waters.
It is the HDOH’s responsibility to ensure the public’s safe use of our waterways. As a microbiologist, I have spent my entire professional career looking for better technologies to improve human health, and I applaud the DHOH’s efforts to find new technologies to test our waterways. However, in their assessment of a new technology, their conclusion that there is no human health risk from the high level of bacteria measured regularly in the Waiopili Stream in Mahaulepu is not justified and falls short of the agency’s mission to protect public health.
It is my opinion, and that of the Surfrider Foundation, that the HDOH should take the more prudent and precautionary approach to continue warning the public of potential health risks of polluted water exposure, even while still trying to figure out where the pollution is coming from and the specific health risk posed. This includes warning the public of high bacterial counts in our waterways that exceed the EPA’s standards for human health.
A more responsible conclusion to draw from the results of the Mahaulepu and Waikomo Watersheds PhyloChip Source Tracking Study would be to acknowledge the inconsistencies in the data and to outline the need for further studies needed to more precisely determine the public health risk in these watersheds (as well as bacterial contamination sources!). These studies determine the presence and abundance of pathogens in the stream that can make people sick.
In conclusion, there is a well-established relationship between bacterial contamination of water—regardless of the source—and the burden of disease and economic loss it can wreck on a community. It is of grave concern to me that the HDOH would use inconsistent and conflicting data generated by this study to make overarching pronouncements about the safety of Kauai’s waterways. It is unfortunate that an organization charged with protecting the public would not take a more precautionary approach to protecting public health when exact threats are still to be determined. It is dangerous territory when incomplete science is used to guide public policy, regardless of the motives.
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John P. Alderete, PhD, MBA, is with the Surfrider Blue Water Task Force on Kauai.
