-->
A
CRITIQUE OF THE HAWAII DEPARTMENT OF HEALTH PRESS RELEASE ABOUT THE KAUAI
WATERSHED FECAL BACTERIA
STUDY:
Mahaulepu
and Waikomo Watersheds PhyloChip Source Tracking Study, Hawaii
RH BENNETT PhD
Applied Life Sciences LLC
The following is a scientific critique of the Hawaii Department of Health water quality
study: press release. It is
substantially remedial to the point of purposeful disinformation. I have been working as an infectious disease
microbiologist, in the area of water quality for over 40 years, 20 years in
Hawaii, and the balance in the West and internationally. The controversy is anything but new.
The full UC Berkeley study is available at the link in the references
The Press Release June 5, 2019
HONOLULU – A new Hawai‘i Department of Health (DOH) water
quality study shows high bacteria counts historically observed in the
Māhāʻulepū sand Waikomo watersheds on Kaua‘i are not associated with human
waste.
The
study did not attempt to account for historical levels of the official DOH
Indicator Bacteria, the genus Enterococci, and the species Clostridium
perfringens. Instead, the study examined for genetic evidence of the gut
microbiomes of common animals, including human.
The indicator bacteria are not the least human-specific. The ENT test has a fecal ENT detection error
of 50% (4).
While
researchers were unable to pinpoint the exact sources of the bacteria, they
conclusively determined human waste is not the cause of bacterial contamination
in the water. The study is now available to the public online through the
department’s Clean Water Branch webpage.
The
study design could not determine the “exact source,” instead it can be
determined if the fecal bacteria genetic signal was from a particular animal
species and in many observations, animal fecal signals were detected. Human fecal signals were not detected in the
watersheds at the time of testing. It
cannot determine what happened in the past.
“We conducted a study using the latest technology available
and determined the high bacteria counts in Māhāʻulepū Valley, which have been a
concern for many years, is not linked to any human sewage sources in the area,”
said Health Director Bruce Anderson. “With this new information, we can assure
the public that recreational waters in Waiopili Stream and nearby beaches do
not pose an imminent health threat to swimmers.”
There
are no sewer systems, per se, in the watershed. Rather there are cesspits and
wastewater injection wells. A human
fecal signal was detected in wastewater injection wells and from a water
seepage site near the coast. A tracer study in West Maui clearly showed an
injection well ocean connection (5).
Seawater
was not tested so NO estimation of swimmer’s risk can be stated for other than
wishful inference without data to support it.
DOH contracted the Lawrence Berkeley National Laboratory
(Berkeley Lab) to understand better what may be contributing to the periodic
high bacteria counts in the area. Their findings validated the results of a
similar sanitary survey from 2016.
The
study was not designed to understand the periodic high bacteria counts (ENT and
CP) The data from the DOH and this study
are NOT directly comparable as the DOH tests are not accepted as a valid
indicator (3,8) even though the EPA requires it for the states use of federal
Beach Act funding.
What
the study did show is that at this time there is little if any evidence of
human fecal signals in the creek watershed.
How long a signal would persist after having a strong signal in these
watersheds is not known. ENT has some
persistence in the environment (1,10).
Using
PhyloChip, an innovative microbial source tracking tool, the Berkeley Lab
scientists found that neither human nor animal waste is the sources of any high
counts of traditional fecal indicator bacteria, such as enterococci and Clostridium
perfringens, in the Kaua‘i watersheds.
Phylochip
is not just a microbial tracking tool.
It is a broad genetic probe designed to broadly identify bacteria in an environmental setting where
there is likely to be a mix of fecal bacteria types from different species. Its strength
comes from the fact that the microbes need not be grown in the lab to identify
them. In the environment, there a
significant number of bacteria we do not know how to grow in the lab, and more
importantly, there are stressed bacteria that are alive but do not grow. This is a significant weakness of traditional
diagnostic microbiology, like the ENT assay.
It
is a misnomer to call the official tests fecal indicators as both bacteria are
ubiquitous in the environment. ENT can
be found in large number is beach sand and must not be interpreted to imply
fecal contamination (10). Similarly, CP
is common to soils.
“We plan to hold community meetings later this summer on
Kaua‘i to thoroughly explain the survey findings and will give the public an
opportunity to ask questions of state health officials and Berkeley Lab
scientists,” Anderson added. “While this is a great step forward in
understanding human health risks associated with the presence of bacteria in
water in this area of Kaua‘i, this is certainly not the end. Further research
like this Kaua‘i study is needed to guide the department in making health and
safety recommendations to the public.”
Berkeley Lab microbial ecologists, Gary Andersen, Ph.D., and
Eric Dubinsky, Ph.D., led the survey efforts with the support of DOH’s Clean
Water Branch.
DOH
failed to state the EPA is the major funder of the project and the release of
the final report was months in the making
After completing this
survey and finding no evidence of widespread sewage system leaks, the Berkeley
Lab ecologists proposed that the high counts of fecal indicator bacteria in
Kaua‘i’s waters are likely due to the use of traditional tests for enterococci
and Clostridium perfringens, which were not designed for use in tropical
regions. Enterococci and other bacterial indicators are naturally found in
soils and other animals and flourish in environments outside of their typical
biological hosts. The ecologists note that this phenomenon is common in humid,
tropical settings like Hawai‘i.
According
to the maps on the study, there are very few onsite wastewater systems, known
as cesspits in the watershed. Only three
coastal seeps were tested, and one had a pronounced human fecal signature. It did not test groundwater in areas of high
cesspit density; thus, the conclusion about system “leaks” is without
substantiation. Tidal action is known to move bacteria from groundwater into
the sea (6). While the warm moist tropical environment is conducive to the
survival of bacteria in general, the study did not examine the extent to which
they “flourish” implying they grown and reproduce. The extended survival of the indicators is
documented even in cool climates (7).
A
recent state study reports groundwater contamination risks from cesspits (9).
The
study shows that the natural presence of these bacteria in water does not necessarily
put people at higher risk of gastrointestinal illness. Until a more appropriate
and valid indicator of health risks in Hawai‘i waters can be determined, the
health department will continue testing according to federal guidelines and
standards.
Many
studies from a wide variety of beach settings have shown that the indicator
bacteria used by DOH do not correlate with increases swimmer risk of infection
(2,3).
Studies
conducted by the EPA where there was a strong correlation are in waters where there
is known wastewater or sewage release.
Such was the case for the Honolulu area as partially treated sewage is
no longer discharged to the ocean.
Additional significant findings from the study include:
• High counts of
fecal indicator bacteria in some areas of the Māhāʻulepū watershed may be from
cows and feral pigs, but these were isolated incidences and popular beach areas
downstream from these areas were clean.
The
meaning of clean is not a term used in descriptive microbiology, and its use is
misleading.
• There is no
connection between the Makauwahi Cave and the Māhāʻulepū watershed as a conduit
for fecal contamination, which was one pollution source posed as a hypothesis
after the completion of the 2016 study.
It
would be more precise to state that no connection was apparent. Given the nature of volcanic geology,
conduits cannot be ruled out. The data
suggested there was no connection at the time.
• In the Po‘ipū
area, one coastal seep showed that there may possibly be pollution linked to
injection wells. However, the routine coastal beach monitoring in the Po‘ipū
area by DOH does not indicate chronic high counts of fecal indicator bacteria.
This
is a very misleading statement. There was a strong human fecal signal in Seep
6. It is contaminated; its exact source
was not investigated. However, the most
likely source given the volume of wastewater dumped into the well. No wastewater injection well in the state is
required to determine the fate of the wastewater. Given the penetration of seawater into the
subterranean estuary, a hydrologic connection to the sea is well established in
a great many locations in Hawaii.
Researchers
Andersen and Dubinsky applied
the Phylochip with scientific rigor as we should expect. They did show quite conclusively that a
widespread human fecal microbial signature was not present, at the time, in two
Kauai watersheds. If there were a septage dump in the watershed, over time,
microbial decay would reduce the human signal.
That research has yet to be conducted.
Wastewater injection wells had a very strong human fecal signature. One nearby seep also had a strong human
signature.
They did demonstrate again what others have
shown, that ENT and CP are nonspecific markers and can yield high numbers in
the absence of a human fecal signature or other definitive testing. This relationship is well known at HDOH, the
EPA, and to most all water quality researchers.
Its continued use is an artifact of poor public policy at both the
federal and state levels. We are remise
when we make excuses for a diagnostic test with a 50% error rate. We would not tolerate an HIV blood test that
was wrong half of the time. It would
never get FDA approval.
As
always in research answers raise more questions. The key question is now, what is the extent
to which human fecal bacteria signatures occur in the nearshore beach water and
how long to they persist. We know that
ENT is a statistically invalid indicator for recreation waters. ENT has a 90% die-off rate in cool marine
water of 22 to 122 hours in the absence of sunlight. Sun UV can lower ENT counts in a matter of a
few hours. Thus samples collected from 10 to 2 PM can be false negatives as
demonstrated in Florida (11).
GI
Illness from recreation exposure to human waste-contaminated water is not due
to bacteria; it is due to the Enteric virus (8), such as the Norovirus aka the
Cruise Ship Virus. Thus, needed are studies to
sample marine waters with the Phylochip and measure the enteric virus.
Only then can we pronounce with some confidence, the relative GI safety of our recreation waters.
END
References
Andersen, G, and
Dubinsky E., Mahaulepu and Waikomo Watersheds
PhyloChip Source Tracking Study, Hawaii
1.
Byappanahalli, M., and Rl Fujioka.
"Indigenous soil bacteria and low moisture may limit but allow faecal
bacteria to multiply and become a minor population in tropical
soils." Water Science and Technology 50.1 (2004): 27-32.
2.
Colford Jr, John M.,
Timothy J. Wade, Kenneth C. Schiff, Catherine C. Wright, John F. Griffith,
Sukhminder K. Sandhu, Susan Burns, Mark Sobsey, Greg Lovelace, and Stephen B.
Weisberg. "Water quality indicators and the risk of illness at beaches
with nonpoint sources of fecal contamination." Epidemiology (2007):
27-35.
3.
Fleisher, Jay M., Lora E. Fleming, Helena M. Solo-Gabriele,
Jonathan K. Kish, Christopher D. Sinigalliano, Lisa Plano, Samir M. Elmir et
al. "The BEACHES Study: health effects and exposures from non-point source
microbial contaminants in subtropical recreational marine waters." International
journal of epidemiology 39, no. 5 (2010): 1291-1298.
4.
Ferguson, Donna M.,
John F. Griffith, Charles D. McGee, Stephen B. Weisberg, and Charles Hagedorn.
"Comparison of Enterococcus species diversity in marine water and
wastewater using Enterolert and EPA Method 1600." Journal of
environmental and public health 2013 (2013).
5.
Glenn, Craig R.,
Robert B. Whittier, Meghan L. Dailer, Henrieta Dulaiova, Aly I. El-Kadi, Joseph
Fackrell, Jacque L. Kelly, Christine A. Waters, and Jeff Sevadjian.
"Lahaina groundwater tracer study--Lahaina, Maui, Hawaii." (2013).
6.
Lee, Eunhee, Doyun Shin, Sung Pil Hyun, Kyung‐Seok Ko, Hee Sun Moon, Dong‐Chan Koh, Kyoochul Ha, and Byung‐Yong Kim. "Periodic change in coastal
microbial community structure associated with submarine groundwater discharge
and tidal fluctuation." Limnology and Oceanography 62,
no. 2 (2017): 437-451.
7.
Lessard, Evelyn J.,
and John McN Sieburth. "Survival of natural sewage populations of enteric
bacteria in diffusion and batch chambers in the marine environment." Appl.
Environ. Microbiol. 45, no. 3 (1983): 950-959.
8.
Lipp, Erin K.,
Samuel A. Farrah, and Joan B. Rose. "Assessment and impact of microbial
fecal pollution and human enteric pathogens in a coastal community." Marine
pollution bulletin 42, no. 4 (2001): 286-293.
9.
Whittier, R. B.,
El-Kadi, A. I., (2014). Human health and environmental risk ranking of onsite
sewage disposal systems for the Hawaiian Islands of Kauai, Maui, Molokai, and
Hawai‘i. Report submitted, State of Hawai‘i Department of Health and Safe
Drinking Water Branch, Honolulu, HI, 258 pp.
10.
Yamahara, K.M., Walters, S.P., Boehm,
A.B., 2009. Growth of Enterococci in Unaltered, Unseeded
Beach Sands Subjected to Tidal Wetting. Appl. Environ. Microbiol. 75, 1517–1524.
11.
Paul, John H., Joan B. Rose, Sunny Jiang, Chris Kellogg, and
Eugene A. Shinn. "Occurrence of fecal indicator bacteria in surface waters
and the subsurface aquifer in Key Largo, Florida." Appl. Environ.
Microbiol. 61, no. 6 (1995): 2235-2241.
No comments:
Post a Comment