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BACKGROUND
Outbreaks of infectious diseases associated with public swimming and
bathing facilities (PSBF's) are well documented in the public health
literature. The situation is complicated by the emergence of Cryptosporidium parvum,
a foodborne and waterbome protozoan. This organism been transmitted by
PSBF's,1,2,3 and it is difficult to eradicate from water even by standard
disinfection methods.
The maintenance of optimum sanitary conditions and the minimization of risk of disease
transmission associated with PSBF's are best achieved by adherence to standards in the
construction and operation of the facilities and the appropriate training and
certification of facility operators. In Kansas there are no statewide regulations for the
construction or operation of public PSBF's, and there are no certification, training, or
licensing requirements for facility operators. Cities and counties often have ordinances
addressing these issues.
Health care staff and environmental health staff of state and local
health departments may be called upon when there is a potential or
perceived public health risk associated with a PSBF. Such situations most commonly arise
as the result of complaints regarding facility operation or reported incidents of
contamination with feces, blood, etc.
General Guidelines for Assessment of
Overall Quality of a Facility's Operation
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Training and Skills of the Facility Operator (FO)
Appropriate training and retraining of the FO is an important component
of sanitary operation of a PSBF. Various standards and credentialing systems are available
such as Certified Pool Operator (CPO) status issued by the National Swimming Pool
Foundation. The National YMCA has its own training and certification program (Pool
Operator on Location). Various jurisdictions may have licensing requirements for FO's
which may be predicated upon other credentialing systems or upon standardized or locally
developed training and testing.
Every facility should have a designated FO, and that individual's
qualifications should be known to the owner/manager of the facility (school, motel, health
care institution, fitness center, etc.) in which the PSBF is located.
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Recirculation and Filtration
Continual recirculation and filtration of the water in swimming
pools and other PSBF's is essential to the removal of solid materials, oils, and other
substances which directly contaminate the water and reduce the effectiveness of the
disinfection process.
An adequate recirculation system should operate at a level to
completely replace one pool volume every eight hours. The system should be operated 24
hours a day during the pool season and have the capacity to maintain a one-volume
replacement time of six hours during periods of heavy use. The system should use a
diatomaceous earth or sand type filter. There should be a schedule of regular backwash
cleaning of the filter(s). Backwash water should be disposed of into an approved sanitary
sewage system.
If adequate recirculation and filtration is maintained, the water
should be clear enough to allow clear visualization from the pool deck of the main drain
at the deepest part of the pool. This standard should apply even during heaviest use of
the pool.
- Disinfection
An adequate disinfection process is the central component of a
system to prevent the transmission of disease in PSBF's. Although chlorine (hypochlorite
or gas) is the most commonly used disinfectant, bromine may also be used. The disinfectant
feeder equipment should be integrated with the recirculation system and should have the
ability to accurately monitor and control disinfectant flow. Although hand and batch
feeding are still practiced, both are to be discouraged in favor of a metered feeder
mechanism allowing continuous dispensing of disinfectant.
The appropriate indicator of effective disinfectant levels is free
residual chlorine. The free residual chlorine level should be maintained between 2.0 ppm
and 3 ppm for pools and between 3.0 ppm and 5 ppm for spas, whirlpools, and hot tubs. In
order for disinfection to be effective at this level, the pH must be maintained between
7.2 and 7.8," and the temperature should be maintained at or above 70 degrees (F).
Disinfectant levels and pH should be tested and adjusted (if necessary) at least twice
daily and as often as hourly during heavy use.
Responding to Fecal Accidents in PSBF1s
The most common contamination accident which is
likely to be reported and which requires a prompt response is a fecal contamination of a
PSBF by a swimmer/bather. Human feces are replete with microorganisms, some of which may
be human pathogens, readily transmitted by recreational water contact. Release of blood into
PSBF water may commonly occur and come to the attention of swimmers and/or the FO.
However, blood is usually sterile, and bloodborne pathogens such as HIV or Hepatitis B
virus are not known to be transmitted by recreational water contact. Therefore, unless the
release involves a large volume of blood such as would result from major trauma, no
response is necessary. In such cases, pool closure and clean-up would be necessary
primarily for aesthetic purposes.
Efforts to prevent fecal accidents should be undertaken.
There should be a posted pool policy that no one with diarrheal illness or with fecal
incontinence should use the facility. In order to minimize risks, a policy of excluding
non toilet-trained infants and toddlers is recommended. Alternatively, to accommodate such
children or disabled individuals who may have some fecal incontinence, there should be a
requirement that such swimmers wear commercially available "swimming
diapers."
The primary objective of a response to a fecal accident is to
discontinue use of the facility until the water can be returned to a quality level such
that the risk of disease transmission is minimized. Upon being notified of an accident,
the owner/operator should suspend use of the facility for the time necessary to carry out
the appropriate remediation procedures.
Smaller facilities such as hot tubs, spas and whirlpools should be
drained, sanitized (with a 1:10 chlorine bleach to water solution or equivalent
disinfectant), and refilled with clean water following a fecal accident and prior to any
further use.
With larger facilities for which frequent refilling may not be
economically feasible, the following steps should minimize risks for swimmers/bathers:
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All visible contamination should be removed by
net or vacuum. If the recirculation vacuum system is used, the
contaminated water removed by the vacuum should be directed into an
approved sanitary sewage system and not back into the recirculation
system.
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A hyper chlorination procedure should be performed as described below.
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Prior to reopening the facility for use, the
recirculation-filter system should be operated for a sufficient time to
complete three one-volume replacements, after which the filter(s) should
be backwash cleaned and the backwash water appropriately disposed of.
Larger facilities, including swimming pools, should be drained,
sanitized, and refilled with clean water prior to any further use if the facility
has been epidemiologically implicated in the actual transmission of an infectious disease
regardless of whether or not a fecal accident has been documented.
Hyper chlorination
Hyper chlorination consists of sustaining a specified, high concentration of free residual
chlorine for a period of time adequate to destroy infectious organisms. The measure of
hyper chlorination is "contact time" (concentration of free residual chlorine
in parts per million multiplied by the time, in minutes, for which that concentration is
sustained). A contact time of 30 (3 ppm for 10 minutes, or other combination) should
destroy most known organisms of concern. One exception is C. parvum, for which
a contact time of 9,600 is necessary to assure destruction of oocysts. It is recommended
that, in response to all documented fecal accidents in PSBF's, a contact time necessary
to assure destruction of C. parvum oocysts (10 ppm for 16 hours, 20 ppm for
8 hours, etc.) be attained.
In order that the hyper chlorination procedure be effective, it is
essential that: (1) during the procedure, the free residual chlorine concentration be
continually monitored; (2) the water temperature be maintained at 70 degrees (F) or above
for the full contact time; and (3) the pH be maintained in the range of 7.2 - 7.5.
Useful Resources
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