

The
Dreaded E. Coli bacterium
What is the
likelihood of infecting your pool?
In two words,
practically zero. While it makes good press and brings the doctorates
and doomsayers out of the woodwork with predictions of another plague,
statistics and science weigh heavily in your favor. Taking fastidious
care of your water remains more important than ever, of course
worth underscoring here. And emphasizing appropriate training to
minimize ingestion by toddlers and swimmers becomes one of the best
preventatives. But first, let's examine the scare itself in the
context or reality.
The aquatic
world has been fanned into a frenzy over what is currently known
as the "FECAL ACCIDENT"! A subject of humorous conversation
during AFO classes and elsewhere, public reaction and legitimate
concern have made it no laughing matter. Worse, were rapidly
becoming saddled with new rules that make the various states
codes ever more inconsistent and the running of our pools and parks
more difficult than ever. The discovery of a "pool stool"
may be quite a shock to the unsuspecting breast-stroker in lane
two but – according to many medical authorities and water-treatment
experts – it should be nothing to warrant a 911 call to the
Centers for Disease Control in Atlanta!
Meanwhile our
nations health departments, earnestly attempting to provide the
best in protection for our swimming-pool patrons and rightfully
concerned about a few apparent outbreaks of cryptosporidiosis and
the more recent and sensationalized E. Coli infestation in Atlanta,
are reacting at a fever pitch. The resultant procedures and precautions,
when heeded, are so costly in time and effort that they are threatening
to put some pools and many waterparks practically out of business!
One exasperated
operator recently told this writer that "if I had to shut down
for a day each time we encountered suspected fecal material in our
park's water, I'd be closed all summer!" Another old-timer
said "I do what's worked for me over thirty years, and it doesn't
include closing my pool!" These are common laments. And the
extreme nature of the more recent procedural requirements for such
encounters is causing many to take a more practical approach, ignoring
the "rules" altogether. (Please be aware that neither
the Professional Pool Operators of America, The Pumproom Press nor
this author is advocating the sidestepping of health-department
guidelines; one courts liability when not following published requirements.
It is, however, reasonable to examine the extremes and discuss them
with your environmental health specialists and other regulatory
agencies
)
Lets look
at a few logical and hard-to-refute concepts bearing on the subject
of pool-water sanitation or the lack of it.
1. Statistical
improbability: Millions public pools have been operated throughout
this century, many with equivalent organic loads and far less sanitation
awareness or disinfectant control than we have today, yet extremely
few pools have ever contributed to the outbreak of disease. It is
true that a New York pool was blamed in the late 1940s for initiating
the terrible Poliomyelitis outbreak, a Los Angeles pool and one
or two others manifested crypto in the early 1990s, a cruise-ship
spa recently infested travelers with Legionnaire's Disease, and
many spas have been blamed for pseudomonas or other biounmentionable
infestations over the years. The recent, lone E. Coli manifestation,
however – ostensibly traced to the Atlanta waterpark –
is the only E. Coli O157:H7 ever blamed on a body of sanitized water.
Serious doubt exists that this water-park kiddie pool was in fact
the source of the infection.
Looking at the
numbers, it is revealing to note the odds. Let's estimate that our
210,000 public pools (high-load and low, full-time or seasonal)
operate an average of 14 hours per day for one third of the year
and 8 hours a day for the other two thirds, serving an average annualized
daily attendance of roughly 50 people. Considering that each swimmer
is in the water one-quarter of the pool's open hours – that's
9.5 billion swimmer-hours per year. And the Atlanta debacle appears
to be the first E. Coli case on record
just a single occurrence!
If one considers it takes a fraction of a swimmer-hour during infectious
conditions to contract the disease, the statistical track record
against likely infection becomes truly staggering.
And consider
drownings in this country. We experience about 1300 tragic drowning
losses each year in swimming pools, figuring such occurrence is
just 20% of the reported 6,500 total drownings per year from all
causes. The likelihood, therefore, that an E. Coli outbreak will
occur is hundreds, maybe thousands of times less than the probability
that you will have a drowning in your pool this year. And that's
if nearly one E. Coli outbreak per year actually happens!
2. Daily fecal
introduction: In busy public facilities everywhere, the bacteriological
and sometimes physical equivalent of a "fecal accident"
is introduced into the pool water every single day the pool is in
use. How much fecal material do you suppose is actually released
into the pool by a thousand swimmers in the million-gallon wave
pool, or a hundred or so toddlers in a few thousand gallons of wading-pool
water? What amount, when, and from where?
How can we be
delicate in describing this stuff...? Lets just call it cheek
wash! Imagine all those kids hurriedly finishing the paperwork after
a trip to the commode, rinsing the last into the pool water itself.
Its not
a pretty thought, but one physiologist estimates a tenth of a cubic
centimeter of fecal material is rinsed into a pool by every bathing
patron who enters the water! Naturally the more hygienic of us would
contribute less, while others might introduce quite a bit more...
In any case, for each 100 swimmers, ten cubic centimeters –
about one tablespoon's worth – is released into our pristine
pool water. Five hundred swimmers could easily match a very large
one-time release of solids. And none of this subtle but solid organic
material is ever scooped out of the water as is the more obvious
pool stool. Theres none of the fanfare, hoopla or sensational
ritual that one finds so commonly attached to the classic floating
discovery! It just stays in the pool, to be oxidized, sanitized
and maybe even filtered – while the hazard of this daily occurrence
to humans is, thank goodness, minuscule.
3. Training
the kids as well as the operators – a new look at infection
prevention: There's no doubt that nationally recognized pool operator
certification, like NRPA's AFO program, is essential for the safe
operation of public pools. We no longer can trust the seat of our
collective pants or what the guy at the pool store tells us. But
training the toddlers and the swimmers not to ingest pool water
is a fairly fresh idea that could virtually eliminate infection
even in marginal water. Parents and trainers should impress on their
kids at a very young age that there's water to drink and water in
which to swim. Designated water from drinking-water fountains and
other appropriate sources must be stressed as only safe water to
swallow! Most parents polled are not currently doing this –
and their kids commonly gulp pool water. It seems as if it could
be a simple addition to youth training, as essential as the washing
of hands. Haven't we all swum in untreated water – from pasture
ponds to the mighty Mississippi – with our lips tightly sealed?
This author water-skied in Saigon's Mekong River some years ago,
with floating feces as common as the leaves and twigs, but he "didn't
drink the water". And he didn't get sick.
4. Sanitation
certainty: Lets face it. Pathogens, including cryptosporidium,
pseudomonas auruginosa, staphococcus and, for sure, coliform, are
going to be introduced – most of them every single day –
into our busy pools! Maintaining an Oxidation/Reduction Potential
(ORP) of 750 millivolts or more. thats equivalent to just
half-a-part "free", unstabilized, un-combined chlorine
at a pH of 7.4 – will do what its always done; it will
render the pool safe for human use. (While beyond the scope of this
article, ORP is the qualitative measure of what's in fact going
on in the water – far more reliable a measure than parts per
million vs. time
)
Regarding the
disinfection potential of chlorine (or any appropriate sanitizer)
in the context of E. Coli, it doesn't take much. The coliform family
is used as the baseline measure of minimum sanitation. Even single-digit
numbers of such organisms found under the microscope indicate the
sanitizing job is incomplete. Research has shown this pathogen experiences
a three-log deactivation (just one surviving in a thousand) in barely
1.2 seconds when free-floating in water which exhibits 750 millivolts
ORP, and in about ten seconds at a mere 650 millivolts – achieved
by an unfettered .1 ppm "free" chlorine at pH of 7.3.
This is the World Health Organization's minimum qualitative value
for appropriate sanitation, now being considered as a minimum in
many state swimming-pool codes. Even trace values somewhat lower
than 650 mV. will result in bug deactivation too – although
the time required is sometimes excessive.
Considering
again the Atlanta waterpark incident (or one in any other extremely
high-load, high dissipation pool in which fecal matter is introduced
in a scattered fashion with, possibly, marginal chlorine or bromine
residuals), E. Coli still has little chance of surviving for periods
measured beyond mere minutes. Hours or days of infecting persistence,
as has been implied by news reports, enter the realm of absurdity.
Even those bacteria safely embodied deep within organic particulate
of visible dimension are doomed. The oxidizing process or, eventually,
the filtering will consume or remove the suspended material. Given
the remote possibility of such pathogenic survival into as much
as a full day, a child nonetheless must ingest the very parcel of
water containing the particulate in order to be infected! Homogeneous
distribution of free bacteria may be possible in completely un-sanitized
water, however fecal particulate from an isolated event cannot possibly
be uniformly distributed or of significant density to assure most
ingested water contains E. Coli-bearing solids. The preponderance
of the water "parcels" are, logically, sanitary and free
of bacteria.
This observer
asserts that, while the possibility of infecting a single child
within, say, an hour of diarrheic contribution in marginally sanitized
water exists, the possibility of infecting greater numbers reduces
exponentially. Further, occurrences of infection spanning two adjacent
days then another, five days later (as presumed in the Atlanta event)
are virtually impossible. Even if the "infecting child"
returns repeatedly, will he defecate again and again, with chlorine
coincidentally low each time?
So what about
all these extreme measures frantically directed by our paragons
of public health? Superchlorinating a closed pool for a day, sanitizing
the filter if not changing the media, even draining the pool and
chlorine-washing the pool shell Caddy-Shack style are measures recently
directed. Requiring tightly sealed infantwear, even nude showers
after each bowel movement (hopefully in the "facility")
and bactericidal scrubbing of hands afterwards? One pool operator
said "they'll soon have us requiring stainless-steel diapers
and duct tape on the kids!"
Closing and
super-treating the pool after a "fecal accident" is a
little like washing your hands for one meal each week. Does it make
any sense to go overboard one or two days a month, disrupting aquatic
programs, wasting water and adding maintenance costs and hours,
if the cheekwash just happens to be lumped all in one spot or area
on those particular days? This observer thinks not.
5. Automation
of water variables: Chemical automation is essential for "well
managed water" in busy, public pools these days. Managed pH
and ORP values are essential, moment by moment. Manual tests, record
keeping and regular monitoring of the systems by a certified, responsible
operator add to the picture, further assuring safe water continuously.
The best modern controllers allow remote monitoring, control, and
detailed analysis, as well as data collection. Most important, secure
archiving of water values can be achieved by downloading for storage
using a remote computer. Technology has much to offer, assuring
safer water in our overtaxed pool systems – with healthy kids
the result. We should avail ourselves.
~kw |