Water Quality Monitoring Needs Reinvention
R. H. Bennett Ph.D.
Applied Life Sciences LLC
The recent editorial by the Director Bruce Anderson of the Hawaii Department of Health makes some assurances that the agency is monitoring recreation water bacteria, and all is well. Unfortunately, all is not well, and it is not that the agency is doing something wrong. The methods are grossly obsolete, and there is ample scientific evidence to that fact. The method is written into the US Beaches Act and to qualify for the financial support the state must use the method. Once again, politics usurp science.
The indicator bacteria measured is the genus Enterococci. In recreation waters where there is no known discharge point of treated human wastewater, the test is less than 50/50 for predicting risk from the presence of human disease agents. Those agents are typically virus that causes gastroenteritis. In the genus Enterococci, there are 30 plus species detected by this test. Only two species are common in feces of most animals, and humans. What makes this test very imprecise is the fact that these two species of Enterococci as well as many others grow readily in the environment and not just soil. Just about any place, there is moisture and organic debris these microbes can be found. Concrete storm drains, sewer pipes, coastal wetlands, taro fields, and stream sediments all can support the growth and persistence of the bacteria.
The Director asserts that this soil growth issue is unique to tropical Hawaii. Unfortunately, that is not accurate. This indicator species are common in the environment with human activities, in places like Alaska, and the lakes of Michigan, to mention places that get rather cold (5,6).
In parts of West Maui and West, Hawaii streams are not prevalent. However, elevated indicator bacteria are commonly detected. In coastal waters, the major source of Enterococci is the beach sand itself. Entero persists there very well. Any event, including Spring Tides that stirs the sand, can suspend the bacteria to the water column (2,3,4). If beach water is tested soon after such an event, high indicator numbers can be found. The health risk is negligible in most cases. The “Entero” test provides no distinction of the relative risk.
To be forthright, we cannot project the disease risk from any bacterial indicator measurement. There are far too many false positives and false negatives. If a medical blood test were only correct half the time, it would never get FDA approval. The EPA scientists we know would love to work on this problem, but there is no political will at the top.
Amidst all this uncertainty, some may feel uncomfortable recreating in our ocean. There is some reassurance. The sun is the greatest disinfector ever known. The UV light penetrates deeply in clear water and will reduce bacterial and viral counts in a matter of a few hours of midday sun (7). Critical is keeping the nearshore waters clear. We are not doing well in this regard. The human waste nutrients that flow into the sea, in contaminated brackish groundwater, streams and rivers, nourish marine phytoplankton, and they grow. The effect is a reduction in light penetration and visibility. Many of our beaches are Federally Listed as Impaired for turbidity. As this happens, the UV of the sun becomes less and less effective, and disease risk will slowly increase as turbidity goes up. This means we need to stop dumping human waste nutrients into the sea. Maui County is hoping the Supreme Court will permit them to continue dumping wastewater indirectly into the sea. Why Hawaii would allow this is not an oversight.
Many communities on the East Coast are actively addressing the problem because their waters turned foul and putrid. Their economy suffers accordingly. So, are we waiting for foul and putrid water too?
Modern innovative approaches to measuring disease risk are coming. The Director mentioned the Phylochip. It is an exact tool that can measure the entire fecal microbiome distinguishing its source. At that time when the test is incorporated into public law and commercialized, the costs will be very competitive.
Another indicator of human waste is a chemical marker called Sucralose. It is known as Splenda, the artificial sweetener. It is omnipresent in human wastewater, very stable and persistent. Tests in Florida waters show it can be detected precisely at very low levels in fresh and marine waters (1). The test method is straight forward, and most analytical labs could conduct the test with some minor investments.
1. Batchu, Sudha Rani, Cesar E. Ramirez, and Piero R. Gardinali. "Rapid ultra-trace analysis of sucralose in multiple-origin aqueous samples by online solid-phase extraction coupled to high-resolution mass spectrometry." Analytical and bioanalytical chemistry 407, no. 13 (2015): 3717-3725.
2. Boehm, Alexandria B., and Stephen B. Weisberg. "Tidal forcing of enterococci at marine recreational beaches at fortnightly and semidiurnal frequencies." Environmental science & technology 39, no. 15 (2005): 5575-5583.
3. Bonilla, Tonya D., Kara Nowosielski, Marie Cuvelier, Aaron Hartz, Melissa Green, Nwadiuto Esiobu, Donald S. McCorquodale, Jay M. Fleisher, and Andrew Rogerson. "Prevalence and distribution of fecal indicator organisms in South Florida beach sand and preliminary assessment of health effects associated with beach sand exposure." Marine pollution bulletin 54, no. 9 (2007): 1472-1482.
4. Goodwin, Kelly D., Melody McNay, Yiping Cao, Darcy Ebentier, Melissa Madison, and John F. Griffith. "A multi-beach study of Staphylococcus aureus, MRSA, and enterococci in seawater and beach sand." Water research 46, no. 13 (2012): 4195-4207.
5. Mutter, Edda A., William E. Schnabel, and Khrystyne N. Duddleston. "Partitioning and Transport Behavior of Pathogen Indicator Organisms at Four Cold Region Solid Waste Sites." Journal of Cold Regions Engineering 31, no. 1 (2016): 04016005.
6. Ran, Qinghong, Brian D. Badgley, Nicholas Dillon, Gary M. Dunny, and Michael J. Sadowsky. "Occurrence, genetic diversity, and persistence of enterococci in a Lake Superior watershed." Appl. Environ. Microbiol. 79, no. 9 (2013): 3067-3075.
7. Sinton, Lester W., Rochelle K. Finlay, and Philippa A. Lynch. "Sunlight inactivation of fecal bacteriophages and bacteria in sewage-polluted seawater." Appl. Environ. Microbiol. 65, no. 8 (1999): 3605-3613.