Quality of Modern Water Parks
Tracynda Davis, M.P.H.
Wisconsin Department of Health and Family Services
those of us focused on water quality and public health,
the proper operation and health management of our nation's
many water parks is a challenging issue. Americans appear
to be flocking to these interactive theme parks more
and more, and yet it is probable that health safety
regimes have yet to be widely developed and enforced.
The result could be increases in waterborne pathogen
exposure and the development of disease symptoms in
a cross-section of the population, primarily young children.
According to the CDC, occurrences of diarrheal recreational
water illnesses have steadily increased since the mid-1980s.
Whether acquired from water parks, swimming pools, spas,
lakes or rivers illnesses caused by Cryptosporidium,
Giardia, Shigella, and E. coli affect the
health of thousands of Americans each year, particularly
young children and those with compromised immune systems.
following research study submitted by Tracynda Davis,
M.P.H. of the Wisconsin Department of Health and Family
Services serves to remind that awareness and good maintenance
practices are fundamental to the public health, particularly
in dealing with public waters. State agencies and facility
managers should be relied upon to provide the healthiest
environment possible. However, in the end, we, the public,
have an equal role in maintaining the public health.
Staying aware of the root causes of disease spread,
practicing fundamental personal hygiene regimens when
we go to public facilities and reporting situations
we believe are harmful to the overall public health
are the keys to maintaining a safe and health environment
for us all.
Homer Nowlin Chair in Water Research
Michigan State University
Chair, Water Quality & Health Council
parks are a rapidly growing element of the United States
tourism industry. In an effort to attract customers,
particularly families, water parks offer creative theme
designs from water slides to interactive water activities.
However, as the designs for the attractions become more
creative, the possibilities for injury and/or infections
to the users are multiplied.
public health responsibility for regulating the operation
and design of water park facilities involves both injury
prevention/reduction and control of the spread of waterborne
disease. To this end, park designers are challenged
to reduce abrasion and impact injuries by cushioning
surfaces at pool basins and edges with various pad materials.
Often, the padded surfaces are designed within a themed
décor to enhance the attractiveness of the park. But
these same features that protect against injuries may
actually increase the risk of waterborne disease by
harboring and distributing bacteria. For example, foam
padding in high traffic areas may provide interstitial
spaces for opportunistic bacteria to escape pool water
disinfectants, and potentially infect swimmers.
Wisconsin Department of Health has completed a 2-year
study of five indoor and five outdoor water parks throughout
the state. The study was initiated as a general survey
of the sanitary conditions at these parks to gain information
that would potentially guide in updating existing regulations
to encompass theming and advanced designs found in modern
water parks. This approach was to essentially provide
data for regulators to make better-informed judgments
for the health and safety of pool patrons and their
comprehensive surveillance of water, materials and surfaces
were sampled and tested quantitatively for of total
coliforms, E. coli, E. coli 0157:H7, enterococci,
staphylococci, heterotrophic bacteria, and Pseudomonas
aeruginosa. All samples were analyzed at the Wisconsin
State Laboratory of Hygiene and taken during unannounced
water samples were further sub-categorized into three
types commonly found in modern water parks -- Activity
pools, Plunge pools, and Wading pools (further separated
into wading pools with or without permanent poured in
place padded surface). Activity pools are greater
than two feet in depth designed primarily for play activity
that uses constructed features and devices. Plunge
pools are those at the terminal end of waterslides,
which carry over 100 gpm of water down a flume. Wading
pools, designed for toddlers and small children,
do not exceed two feet in depth and may have padded,
permanent poured in place impact-attenuating surfaces
either partially or completely submerged in water.
waters were tested for compliance per state regulations
for water quality. Findings were that 90% of the pool
water samples were bacteriologically compliant and 88%
were compliant with free chlorine residuals for pools
as stated in Wisconsin Administrative Code (1ppm for
activity and plunge pools, 2ppm for wading pools)1.
Wading and plunge pools were below the required free
chlorine concentration in 12% of the samples, while
no activity pool samples were chlorine deficient. Most
water parks have automated technology and highly trained
staff, which the authors concluded could explain the
high compliance compared to other pool studies published
focusing on standard pools. Large water parks have more
than one person overseeing a multitude of pools. In
this survey, all employed 2 or more nationally certified
and pad materials
Theming and pad materials used to cushion the impact
of a pool slide or other activities were tested; both
those submerged in chlorinated water, and those considered
damp. Bacteria isolated from submerged features (i.e.
landing pads below surface) probably survive because
porous interiors and/or surface films offer protection
from chlorinated water. The samples located furthest
away from pool water, damp samples, contained the highest
populations of bacteria. Bacteria found on damp surfaces
are also commonly found on people's skin, hair, and
nasal cavities and naturally found in the environment.
Over 30% of the population are carriers of the bacteria
which we found in the materials.2
features were also tested and those designed for young
children and babies were found to harbor the most bacteria.
Probably due to the incontinent nature of user of these
play features, fecal indicators were found frequently
(E. coli 13%, total coliforms 53%, enterococci 87%).
Skin indicators such as staphylococci were found in
up to 80% of the samples. E coli and enterococci were
found in concentrations as high as 1050 cfu/100cm2
and 24,192 cfu/100cm2, respectively. (Figure 1)
E coli 0157:H7, the bacterial strain that caused
an outbreak in a water park in Atlanta, was never detected
in pool water or in any location in the parks.
water samples from pools which contain landing pad materials
were shown to contain very low numbers of target organisms,
further evaluation was done to determine whether landing
on a pad material may discharge target organisms when
under the weight of a bather. To mimic this effect,
a sterile 25 kg container was pushed against submerged
padding material while pool water was simultaneously
collected. The pool water prior to mat compression was
relatively free of target bacteria, wherein only heterotrophic
organisms were found at levels of 257 CFU/ 100mls. However,
water collected during mat compression contained heterotrophs
(9,260 CFU/100mls) as well as S. aureus and S.
epidermidis (228 CFU/100mls and 100 CFU/100mls,
respectively). This suggests using landing pads on the
bottom of a pool or waterslide potentially release more
bacteria into the pool recirculation system. The mats
could offer protection from residual chlorine to these
organisms, but it is not know how long they could survive
The benefits of preventing impact injuries by the use
of pad materials are easily appreciated and permanent
rubber surface attenuating materials poured directly
onto the pool basin were evaluated as well. During the
duration of our study, materials were found to degrade
in chlorine residuals of 3ppm, and pieces of the material
tested positive for all the target bacteria. The water
from wading pools with permanent surfacing materials
are ten times more likely to contain P.aeruginosa
than those without surfacing materials, and three times
more likely to detect S. aureus. (Figure 2)
2. Frequency of Bacteria Detected
of the materials and play features tested provided adequate
cleaning procedures, leaving the pool operator to determine
by sight what is considered "dirty". Features and materials
used in water recreation need maintenance manuals with
a cleaning regiment. Proper cleaning procedures must
be provided and followed to keep microbes from flourishing
in environments lacking a steady stream of chlorine.
the parks were found to be operating properly. Readers
should be cautious not to over emphasis the presence
of these organisms. A study done by Ojima et al suggests
bathrooms and kitchens harbor some of the same microorganisms,
and in similar abundance.3
using pad materials were found to increase the frequency
of bacteria detected compared to the pools without pad
materials. We recommend that if pad materials and play
features are used, they should be considered in inspection
criteria. Though pad materials and play features were
found to harbor bacteria, a link between the materials
and illness has not been established. Pool water is
an efficient vehicle for transporting residual chlorine
to bacteria and the low incidence of positive samples
an effort to reduce the amount of fecal bacteria transmitted,
Wisconsin passed legislation in 2005 requiring diaper-changing
stations in all new pools and water parks. This includes
both sex restrooms, providing an alternative for baby
and small toddler needs in proper locations.
department recommends simple steps to prevent disease
with soap before using pools.
parents not to bring their child to a water park or
any pool if the child has diarrhea
change diapers on pools decks (fecal material can
run off into the pool from the deck if parents are
of this study will be submitted to Environmental Health
Perspectives this spring.
Wisconsin Administrative Code. Chapter HFS 172. Safety,
maintenance and operation of public swimming pools.
Register May 2002, No. 557.
Arch G. Mainous, III, PhD, William J. Hueston, MD, Charles
J. Everett, PhD and Vanessa A. Diaz, MD, MS. 2006. Nasal
Carriage of Staphylococcus aureus and Methicillin-Resistant
S aureus in the United States, 2001-2002 Annals
of Family Medicine 4:132-137
Ojima M, Toshima Y, Koya E, Ara K, Kawai S, Ueda N.
2002. Bacterial contamination of Japanese households
and related concern about sanitation. Int. J. Environ.
Health Res., (12) 41-52.
Quality & Health articles are published periodically
by the Water Quality & Health Council, an independent,
multidisciplinary group that promotes science based
practices and policies to enhance water quality and
health by advising industry, health professionals, policy
makers and the public.