Download BarnesMichael1980

CALIFORNIA STATE UNIVERSITY, NORTHRIDGE
SWIMMING POOL WATER
1\
MAN~GEMENT:
AN EVALUATION OF SELECTED
LOS ANGELES CITY OPERATED SWIMMING POOLS
A thesis submitted in partial satisfaction
of the requirements for the degree of Master
of Science in
Health Science, Environmental and
Occupational Health
by
Michael Stanley Barnes
//
January, 1980
The Thesis of Michael Stanley Barnes is approved:
Mr. Owen Seiver
Dr.
CALIFORNIA STATE UNIVERSITY, NORTHRIDGE
ii
DEDICATION
This thesis is dedicated to Marjan, Ken and Veda.
They've loved and supported me all the way. Thanks.
iii
TABLE OF CONTENTS
APPROVAL
ii
DEDICATION
iii
LIST OF TABLES
vi
ABSTRACT
vii
CHAPTER
1.
2•
INTRODUCTION
1
Statement of the Problem
3
Hypothesis
3
LITERATURE REVIEW
5
Historical Development
5
Development of Sanitary Concern
7
Diseases Transmitted Through Swimming
Pool Water
Unsubstantiated Diseases
Bacterial Quality of Swimming Pool Water
15
21
Direct vs. Indirect Measurement
21
Bacteria as Indicators
25
Reducing the Numbers and Types of Bacteria
3.
7
28
Prevention
28
Treatment
30
Review
35
California Laws and Regulations Relating
to Swimming Pools
36
Summary
39
METHODOLOGY
41
Preliminary Study
41
Collection
41
Analysis
42
Bacteriological Study
iv
42
Collection
Analysis
4.
42
44
RESULTS
Preliminary Study
48
48
Bacteriological Study
5.
6.
56
SUMMARY AND CONCLUSIONS
Summary and Discussion of the Biases in
the Study
57
DISCUSSION
Prevention
Treatment
Chemical
Physical
Review
61
58
61
64
64
66
66
LITERATURE CITED
69
APPENDICES
1. Preliminary Survey Questionnaire
79
2.
3.
Bacteriological Study:
Bacteriological Study:
v
Daily Results
Accumulated Results
82
97
LIST OF TABLES
TABLE
PAGE
1.
Attendance Profile . • . .
50
2.
Chlorine Test Frequency • •
50
3.
Bacteriological Survey:
Results . . . . . . .
56
vi
Accumulated
ABSTRACT
The primary goal of swimming pool water management is
to prevent the transmission of disease through the water.
A comprehensive management program relies on keeping
bacteria out of the water {Prevention), removing or killing
bacteria in the water {Treatment) and program evaluation
{Review).
In this study, a preliminary telephone survey of Los
Angeles City swimming pool managers was conducted which
indicated that potentially serious deficiencies in prevention, treatment and review were occurring.
This led to
speculation that some of these pools might exceed the
maximum allowable levels of total bacteria and total coliform bacteria set by the State of California.
Ten pools were non-randomly selected to take part in
the month-long bacteriological study.
Samples were
collected and analyzed for total bacteria and total coliform bacteria according to Standard Methods for the
Examination of Water and Waste Water 14th edition (1975).
Nine of the ten pools exceeded the State standard set for
total bacteria and three of the ten exceeded the State
standard set for coliform bacteria.
Only one pool met both
standards.
It is suggested that this poor performance is due to
inadequate sanitary training of managers, inadequate managerial support, and inadequate review processes.
vii
CHAPTER I
INTRODUCTION
In an attempt to protect swimmers from undue exposure
to disease spread through the water of swimming pools, the
State of California has promulgated several rules.
These
statutes can be divided into four parts, and are designed
to reduce the potential of swimming pool water as a
vehicle for disease transmission.
First, the State has specified standards which the
construction plans must meet.
In providing for review of
all swimming pool construction plans by a State or local
health officer, the State tries to insure that such plans
adequately provide for the health and safety of the future
patrons.
After a pool of an approved design is built, the
State law provides standards of operation.
These standards
specify measures of prevention and treatment that must be
utilized by the operator.
Finally, the law places respon-
sibility on both the operator and the State or local health
officer to see that compliance with these standards for
prevention and treatment is achieved.
Prevention refers to measures designed to prevent
bacteria, especially harmful bacteria, from entering the
water.
These measures include, excluding patrons and
employees with infectious diseases from the pool, requiring
1
2
all persons to take a hot shower with soap before entering
the pool, directing swimmers to make use of the toilets
before using the pool, using only approved water supplies,
and keeping the area surrounding the pool clean.
Treatment refers to measures taken to render bacteria
in the water harmless as quickly as possible.
Measures
such as filtration, maintenance of adequate levels of disinfectant at proper pH values, and requiring the removal of
floating scum, sputum, and debris are in this category.
Measures making the pool operator and State or local
health officer responsible for proper implementation of
treatment and prevention measures can be classified as
review.
The most important tools of this review are the
sanitary survey which can be done by either the operator or
the health officer, the bacteriological survey, and record
keeping.
In the absence of a recognized epidemic, the
bacteriological survey is the best measure of the adequacy
of existing programs in reducing the potential of disease
transmission through the water of the swimming pool.
A preliminary telephone survey of pool managers at
L.A. City operated pools indicated that the measures of
prevention and treatment specified by the State, in many
instances, were not being implemented.
Serious omissions
were reported which, it was felt, would adversely affect the
amounts and types of bacteria found in water from these
pools.
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STATEMENT OF THE PROBLEM
The State of California, Department of Health, has
stated that by law,
"Bacteriological quality of water in the pool
shall be such that not more than 15 percent of
the samples covering any considerable period of
time shall
(a)
contain more than 200 bacteria per rnillilit~r as determined by the standard
(35 C) plate count, or
(b)
show positive test (confirmed test) for
coliform organisms in any of the five 10
milliliter portions of a sample, at times
when the pool is in use."
It is assumed that a pool with proper implementation
of programs of prevention and treatment would meet these
standards.
Conversely, failure to implement measures of
prevention and treatment will result in an increase in the
numbers of both total and disease-causing bacteria in the
water.
Lastly, it is assumed that a program of review is
necessary as a final check on the implementation and adequacy of the programs of prevention and treatment.
The questions to be answered are whether in the face
of apparent widespread neglect of certain aspects of prevention, treatment and review the bacterial levels at some
pools can be shown to exceed the standards set by the State
and second, if the bacterial standards are not complied
with, how localized is the problem.
HYPOTHESIS TO BE TESTED
Ho:
The water from one or more Los Angeles City
4
operated swimming pools of 10 to be tested,
will exceed the standards of bacteriological
quality set by the State of California.
Ha:
The water from all 10 Los Angeles City
operated swimming pools will not exceed
the standards of bacteriological quality
set by the State of California.
5
CHAPTER II
LITERATURE REVIEW
HISTORICAL DEVELOPMENT
Swimming and bathing pools probably antedate recorded
history.
Marshall (1931) described an evacuated swimming
pool in India which, although 5,000 years old, demonstrates
remarkably advanced technology.
Breasted, in personal
correspondence to Luehring (1939) reported that wealthy
Egyptian nobles had garden swimming pools "as far back as
3,000 BC."
Swimming pools were used by many ancient civilizations.
Wolff (1908) and Schleyer (1909) claimed that pools
for bathing and swimming were common among the ancient
Asiatics, Hindus, Persians, Assyrians and Hebrews.
The early Greeks made an important distinction between
bathing and swimming.
Mehl (1927) noted that the Greeks
built swimming pools with their other physical education
facilities, separate from the Grecian baths beginning in
the fifth century B.C.
The Romans borrowed the idea of a
swimming pool as a recreation facility and improved it.
Bell (1850) stated that the Thermae of Diocletian, built
305 A.D., was unsurpassed in beauty and could accommodate
nearly three thousand people at one time.
The Romans also
served to popularize the swimming pools in areas of their
occupation.
The swimming pool they built in Bath, England,
6
during the first century A.D. was so well constructed that
it was still watertight 1800 years later according to the
Ministry of Health (1929).
After the fall of the Roman Empire, a gap in the
information about swimming and swimming pools occurs.
Swimming as a sport was probably not popular during those
medieval times.
Winslow (1923) claimed that even bathing
and the value of cleanliness declined during this period.
Girard (1832) and Hartwell (1897) described the modern
reemergence of the swimming pool.
The first swimming pools
of modern times were built next to or on natural bodies of
water.
First carne the floating pools.
These may be described
as large perforated tanks suspended from floats, usually in
the form of a dock or ferry.
The perforations allowed for
a simple flow-through of water to rid the tank of accumulating wastes.
The floating pools were followed by similar pools
meant to rest on the bottom.
Girard (1832) reported that
the first pool of this type opened in Paris in 1780.
Scharf and Westcott (1884) claimed that the first known
swimming pool in the United States was of this type, built
during 1791 in Philadelphia.
Finally, landlocked swimming pools were developed.
DeSilver (1829) noted that one such pool was open in
Philadelphia in 1829.
After the passage of the British
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Bath and Washhouse Act of 1846, a boom in landlocked swimming pool construction swept Great Britain.
This boom was
paralleled to a lesser degree in the U.S. and Germany
according to Schleyer (1909).
DEVELOPMENT OF SANITARY CONCERN
It was 25 years after the germ theory of disease was
formulated by Pasteur before anyone applied it to swimming
pools.
Baginsky (1896) was the first who claimed to have
traced diseases to swimming pools.
Mannhiemer (1914) made
an early review of this and other literature relating to
the role of swimming pools in disease transmission.
This
review set off a period of intensive research.
Diseases Transmitted Through Swimming Pool Water
Klassen (1953) divides diseases traced to swimming
pools into two groups:
1) those associated with the use of
the ancillary facilities and, 2) those associated with the
use of the pool itself.
Due to the nature of this thesis,
we will confine our interest to diseases of the second
category.
There are many diseases which have been said to be
contracted through the use of the pool itself.
These
include swimming pool granuloma, folliculitis, pharyngoconjunctival fever, conjunctivitis, enterobiasis, otitis
media, catarrhal otitis, sinusitis, gonorrhea, vaginal
trichomoniasis, scarlet fever, leptospirosis, polio, acute
8
respiratory disease, colds, septic sore throat, pneumonia,
typhoid fever, amoebic dysentery and primary amoebic
meningoencephalitis (PAME).
1.
Folliculitis -- In a recent review of the litera-
ture, Sausker et al (1978) showed that nearly all the
folliculitis caused by Pseudomonas sp (Pseudomonas folliculitis) in this country is caused by Pseudomonas aeruginosa, a ubiquitous organism which rarely causes
diseases in an immunologically competent host.
Jacobson
et al (1976) suggest that a particular environmental
adaptation of some strains of Pseudomonas and certain
virulence factors they possess may be increasing their
pathogenic potential.
Epidemiological evidence indicates that Pseudomonas
folliculitis can be spread through swimming pool water.
Washburn, et al (1976) described an epidemic associated
with the pools at a Minnesota motel in March of 1975.
Ninety-eight of the motel's guests were surveyed.
None
of the thirty-seven who had not used the pool developed
a rash but thirty-two of the sixty-one that had used the
pool developed a rash.
In another study McCausland and Cox (1975) were able
to recover pseudomonads from a motel whirlpool which they
credited with causing a similar outbreak of Pseudomonas
folliculitis.
9
It is thought by some researchers that high temperatures are necessary for Pseudomonas to elicit folliculitis.
Sausker et al (1978) noted that the face, which is rarely
submerged in a hot pool, is also rarely affected by Pseudomonas folliculitis in the cases cited.
If this is true,
then facilities containing a swimming pool which is not
severely heated would not need to be overly concerned with
preventing Pseudomonas folliculitis.
2.
Swimming Pool Granuloma -- The other skin disease
cited in recent literature as being spread through swimming
pool water is swimming pool granuloma.
due to
~cobacterium
Skin granulomas
balnei (marinum) have been reported
since the early 1950's.
Linell and Norden (1954) and
Herlitz (1953) reported 80 such cases from one swimming
pool.
Hellerstrom (1952) and Cleveland (1951) reported
similar outbreaks which were probably due to the same
organism.
Most recently Even-Paz et al (1976) reported 10
cases from Israel.
Epidemiological evidence strongly implicates the swimming pool in the transfer of this granuloma.
Linell and
Norden (1954) noted that all 80 cases in their study of an
epidemic visited the swimming pool frequently, nineteen
reported that the lesions followed receiving a scratch from
the pool wall.
They (Linell and Norden) intentionally
infected themselves, reproducing the disease clinically and
microbiologically, the organism being again recovered from
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the lesions.
They suggested that this organism be called
Mycobacterium balnei.
Further evidence has supported the findings of Linell
and Norden.
Hicks (1977} summarized:
"Swimming pool granuloma (a typical mycobacterial disease} is an infection caused by •••
Mycobacterium balnei.
It is commonly seen
on the knees or elbows, following abrasions
received while swimming in freshwater pools ••• "
However, i t has not yet been determined whether the
bacteria are contracted through the water or from fomites
at the pool such as the pool deck or walls.
Cleveland
(1951} points out that wherever mucous as a result of
expectoration by a user (of the pool} with an incipient or
minimal pulmonary infection exists, so does the causative
bacteria.
Keeping this in mind, both the water and the
fomites must be suspected but the fomites seem to be the
more likely source.
3.
Pharyngoconjunctival Fever -- This disease has
been repeatedly linked to swimming pools for more than 75
years.
Fehr (1900), Gradle (1916} and Bahn (1927} all
reported epidemics of swimming bath conjunctivitis.
In
1927 Bahn reported observing 36 cases of swimming bath
conjunctivitis during two summers, noting that each case
had bathed at a crowded resort seven to fourteen days prior
to onset.
Duke (1932) in his "Textbook of Opthamology"
recognized swimming bath conjunctivitis as a disease entity
claiming it was caused by a filterable virus.
Ling (1936)
11
reported a swimming pool conjunctivitis epidemic.
He cau-
tioned against assuming that swimming pool conjunctivitis
originates only in swimming pools, reasoning that as the
infection was probably of genitourinary origin, it could be
transmitted in other ways.
Thygeson and Stone (1942) attempted to determine both
the severity of the problem and the survival rate of the
virus in tap water.
They sent questionnaires to 50 student
health administrators.
Only one reported the presence of
the disease in epidemic form, and this prior to the adoption of chlorination of the swimming pool.
To determine
survival rates of the virus, suspensions of epithelial
scrapings of an infected patient were suspended in tap
water, and inoculated into a baboon.
It was determined
that a six hour suspension was capable of producing conjunctivitis in the baboon while an eight hour suspension
was not.
In 1943, more cases were reported by Derrick, all with
the same date of onset, and all having only one common experience, the use of the swimming pool.
In Greenley, Colorado, an epidemic of conjunctivitis
associated with pharyngitis, and muscle pain was investigated in 1953 by Cockburn.
The epidemic occurred during
the warmest part of the year, and predominantly among
young people who had frequented the swimming pool during a
hGt spell.
The median date of onset was four days follow-
'
.
12
ing the hottest day of the year, which was also the day of
the greatest attendance at the public swimming pool.
Through follow-up, it was established that some secondary
cases occurred through mutual contact of infected and noninfected children by means of a slide viewer.
Several
attempts were made to isolate the causative organism during
this epidemic; however, these attempts were unsuccessful.
A series of three similar epidemics, occurring concurrently in the vicinity of Washington, D.C., were reported
by Bell, et al.
(1955).
In the outbreaks, several means of
transmission were recognized, but in all cases, close associations seemed to exist between swimming pool usage and
disease.
The Type 3 APC (adenoidal-pharyngeal-conjunctival)
virus was isolated from individuals showing any of a group
of symptoms including fever, pharyngitis, and conjunctivitis.
The occurrence of conjunctivitis among patients who
had been swimming during a two-week period prior to onset
of illness was 45%,
(97 of 216), whereas, of those who had
a history of no swimming, only 30% (13 of 44) had conjunctivitis.
11
The authors indicated that in their opinion
SWimming pools may be a suspected, but unproven source of
infection ...
Finally Ormsby, Fowle and Cockerman (1955), were able
to establish from the convalescent serum of patients from
the outbreaks studied by Cockburn (1953), Bell et al (1955)
and Ormsby and Aitchison (1955) that Type 3 APC virus was
13
common to all three epidemics.
Furthermore, the conclu-
sions of the study conducted by Ormsby and Aitchison in
1955 have not been significantly altered to date.
These
are:
11
1. Pharyngeal-conjunctival fever is primarily
spread in swimming pools and secondarily by
direct contact in the homes of affected children.
2. Symptoms of the disease vary, but typically
consist of unilateral or bilateral follicular
conjunctivitis, preauricular adenopathy, pharyngitis, fever, malaise and muscle pains.
3. Catarrhal otitis media is the chief complication. Corneal opacities develop in many
adults, but are rare in children."
Van de Veen and Van der Ploeg (1958) added the symptoms of nausea, vomiting and diarrhea to those attributed
to Type 3 APC virus.
They also posulated that " ••• irrita-
tion of the nasal or conjunctival mucosa from swimming or
from relatively long exposure to sunlight or both, enables
virus to penetrate into the tissues and, subsequently, to
produce the fully developed manifestations of pharyngoconjunctival fever."
This is similar to the argument advanced
by Taylor (1923) thirty-five years earlier who, while discussing the role of autoinfection in otitis externa said
" ••• It is my belief that this (autoinfection) is due to the
maceration of the delicate dermis by the water, which
breaks the skin and opens up an avenue of infection .•• "
Foy, Cooney and Hatlen (1968) emphasized the need for
adequate chlorination to prevent epidemics.
They studied
an epidemic of pharyngoconjunctival fever among two swim
teams which swam in the morning in unchlorinated water.
14
Afternoon swimmers who swam in chlorinated water (in the
same pool) remained well.
An inadequately chlorinated
swimming pool was also incriminated in an epidemic studied
by Caldwell et al (1974).
Caldwell's group found that 0.3
ppm free chlorine was adequate for control.
Caldwell et al (1974) also showed that conjunctivitis
in swimming pools can be caused by viruses other than
adenovirus type 3.
In the epidemic which they studied
adenovirus type 7 was shown to be the causative agent.
4.
Primary Amoebic Meningoencephalitis {PAME)
PAME
is a recently discovered human disease caused by an amoeba.
A universally accepted name has not yet been determined but
the most prominent candidates are Naeglaria fowleri {Carter
1970), Naegleria aerobia {Singh and Das 1970) and Naeglaria
invadens (Chang 1971).
Since the first documented case was
reported by Fowler and Carter {1965) the disease has been
striking in two aspects.
fatal.
First, it has been nearly always
Second, the epidemiological evidence has almost
always {one exception) implicated nasopharyngeal contamination with the amoeba by way of immersing the head in water.
Probably the most perplexing epidemics of PAME associated with a swimming pool occurred at an indoor swimming
pool in Czechoslavakia.
This was the source of four re-
ported epidemics of PAME between 1962 and 1965 as documented by Cerva and Novak (1968).
The last three epidemics
occurred despite extraordinary precautions taken after the
15
first epidemic.
Finally Kadlec, Cerva and Skvarova {1978) discovered
the source of the repeated epidemics.
During the winter
of 1977-78 investigation of the inside front wall in the
deep part of the pool showed that i t was cracked in
several places.
It was learned that this wall had been
built years earlier to adjust the length of the pool to
exactly 25 meters.
An open space had resulted in between
the newer and older walls.
Upon investigation of this .space, thick layers of
organic material containing pathogenic Naegleria
found.
~
were
They felt that this space had served as a reservoir
since the first epidemic in 1962.
The false wall had pro-
tected the amoebas from disinfectants and cleaning while
the undetected cracks allowed the amoebas access to the
water during periods when the pool level was raised to
facilitate competitive swimming.
It should be noted that state-of-the-art water treatment facilities and methods prevented outbreaks of PAME
from 1965 to 1978 but failed to destroy the amoebae in this
space.
Unsubstantiated Diseases
Many diseases have been said to be spread via swimming
pool water yet lack confirming epidemiological evidence.
Levine {1916) recognized this over sixty years ago when he
stated " .•• The danger of infection in pools has probably
16
been overemphasized.
Nevertheless, we should regard the
swimming tank as a potential vehicle of infection and take
the necessary measures to control its sanitary condition."
The alleged yet unsubstantiated diseases include
trichomoniasis, gonorrhea, syphilis, polio, respiratory
diseases, salmonellosis, hepatitis, enterobiasis and
amoebic dysentery.
Venereal Diseases -- trichomoniasis, a disease caused
by an anaerobic flagellate protozoan Trichomonas vaginalis,
is the only venereal disease which is still thought to
possibly be transmitted through the water at a swimming
pool.
Santler and Thurner (1974) demonstrated that Trichomonas vaginalis could remain viable even in unfavorable
conditions as in chlorination.
They even succeeded in
culturing these organisms from fresh samples of water taken
from swimming pools.
Kozlowska and Wichrowska (1976) made
a similar but more cautious finding, concluding that
without careful maintenance of chlorine levels, chlorination would be inadequate in controlling the trichomonads.
Other recent studies have failed to support the likelihood of Trichomonas vaginalis
dissemination through swim-
ming pool water. Piekarski et al (1972) found that the survival time of trichomonads was very small when they were diluted. In two separate studies Kraus and Tiefenbrunner (1975)
and Balacescu and Grun (1975) failed to findtrichomonads
in
17
any of the 19 pools which (collectively) they had examined.
We can conclude that while the theoretical possibility
of contracting trichomoniasis at a swimming pool is still
being debated, there is at present, no epidemiological
evidence of this occurring.
Fortunately a high free
chlorine residual appears to be effective in reducing the
viability of the organisms.
Gonorrhea and syphilis are venereal diseases which
were once thought to be transmitted through swimming pool
water.
The Committee on Bathing Places of the APHA in its
Third Report (1922) claimed that bathing places were important in the transmission of venereal disease.
Fortunately
for swimmers, no case of any venereal disease being transmitted through the water was ever reported in the literature reviewed.
Skutch (1892) reported an epidemic of
gonorrhea, in a girls shcool, associated with a swimming
pool but noted that " ••• mutual contact of the genital parts
••• and use of a common towel .•• " may have caused the epidemic.
Neither disease is considered to be spread through
use of a swimming pool without direct person to person
physical contact.
Pathogenic Fungi
A spinoff of research into the
presence of trichomonads in swimming pool water was the
discovery of pathogenic fungi.
Kraus and Tiefenbrunner
(1975) found Candida albicans, the causative agent of
candidiasis and Trichophyton mentagrophytes,the causative
18
agent of athlete's foot in swimming pool water.
No allega-
tions that these diseases were contracted through waterwere
found in the literature but it must be considered theoretically possible. An epidemic of athlete's foot at a swimming
pool would not lead one to incriminate the water. The pool
deck is probably a much better site for contracting athlete's foot than the pool water.
On the other hand, an
epidemic of candidiasis associated with a swimming pool
would lead one to suspect the role of the pool water in
transmission, due to its venereal nature.
Polio -- Polio was first demonstrated to be an infectious disease by Wickman (1907). Rhodes et al (1950) showed
that polio virus could be recovered from river water, experimentally contaminated, 188days after inoculation. This lent
credence to the then current speculation that polio may be
transmitted by swimming in water containing the virus.
However, epidemiological studies have failed to show any
correlation. In one of the largest studies, Thompson (1950)
studied 345 cases of poliomyelitis in New Zealand and concluded
that no correlation between swimming and polio could be made.
Still, since epidemics of waterborne poliomyelitis
have been described (Little 1954, Clarke and Chang 1959)
through drinking contaminated water, swimming pool water
must be considered as a possible, if improbable, vehicle
for transmission of the disease.
Respiratory Disease -- In the early 20th century Lewis
(1911), Burrage (1911) and Whipple (1911) observed more
colds, pneumonia and sore throats among pool frequenters.
By 1948, water treatment had advanced to the point that
Gallagher found no significant differences between the
incidence of respiratory disease among boys frequenting a
pool and those not.
Gallagher concluded that the use of a swimming pool
complying with the 1942 APHA standards, would result in no
increase in the incidence of respiratory diseases.
How-
ever, Bliss and Steinmetz (1958) attempted to discredit
Gallagher's study by claiming that since pool frequenters
in Gallagher's study were swim team members, and since swim
team members may represent healthier than average students,
no conclusion could be made from Gallagher's data.
Heinz et al (1977) reported an epidemic of acute
respiratory disease coupled with "swimming pool conjunctivitis."
Klassen (1953) suggested the importance of droplet
infection in the transmission of respiratory disease noting
that " ••• Droplets formed in the air as a result of sneezing
or spurting water with the mouth may remain suspended on
top of the water surface by surface tension and may be a
factor in the transmission of respiratory diseases such as
colds, sinusitis or septic sore throat."
Before respiratory diseases can be classified as
waterborne, further research is needed into viability of
the causative agent in water or more epidemiological
20
evidence is needed.
Until then, it should be noted that
droplet infection of the respiratory tract is probably much
easier to contract through breathing contaminated air than
by taking water into the mouth.
Salmonellosis -- Outbreaks of paratyphoid fever,
probably due to swimming in polluted natural waters have
been recorded.
The Committee on Bathing Beach Contamina-
tion (1959) in a five-year study recorded four cases of
paratyphoid fever evidently contracted by swimming in
polluted water.
This same study isolated Salmonella sp
from bathing water on 569 occasions.
So, even though no cases of disease caused by
Salmonella sp contracted at a swimming pool were mentioned
in the literature reviewed, the possibility of such a
transmission cannot be dismissed.
Infectious Hepatitis -- Like cholera, polio, salmonellosis and many other diseases, infectious hepatitis is
known to be transmitted through the use of infected
drinking water.
Brown (1964) postulated that hepatitis
could be spread to the swimmer simply through the immersion
of the body or by taking infected swimming pool water into
the mouth.
Despite Brown's concern, no allegations of any
case of infectious hepatitis being contracted through the
water of a swimming pool are reported in the literature
reviewed.
Enterobiasis or infection by the pinworm ·(Enterobius
21
vermicularis) is usually transmitted from anus to mouth by
finger contamination according to Faust, Russell and Jung
(1970).
Pinworm eggs are known to be resistant to disin-
fectants and Pospisilova (1973) was successful in recovering pinworn eggs from two swimming pools.
No attempt to
demonstrate the viability of these eggs was reported.
If
viable eggs could be recovered from swimming pool water it
would be reasonable to assume that enterobiasis could be
transmitted through swimming pool water.
Bundesen {1934) established that amoebiasis may be
spread via contaminated drinking water.
Furthermore, since
the cysts are resistant to disinfectants, ingestion of
swimming pool water could serve to transmit the disease.
Again, there is no epidemiological evidence to show that
this has happened.
BACTERIAL QUALITY OF SWIMMING POOL WATER
Direct vs. Indirect Measurement
Mannhiemer's 1914 literature review of diseases
acquired while swimming strengthened the notion of disease
transmission through swimming pool water.
Since few would
deny the inadvisability of swimming in grossly polluted
water, efforts began to find a suitable index of bacterial
pollution.
Bacteriological studies {direct measurement)
already in use for measuring drinking water quality were
applied initially.
These studies were and still are very
22
time consuming.
Therefore many efforts were made to
develop a more easily measured index which would accurately
reflect the bacteriological quality of the water (indirect
measurement).
Tully (1912) attempted to establish an index of pollution by comparison of total chlorine, nitrogen as free
ammonia, albuminoid ammonia, nitrites, nitrates and the
number of bacteria per milliliter of water.
He found no
correlation so proposed no indirect index.
Fair (1920) laid out many logical concepts that are
still considered important today.
He emphasized the
relationship between the number of bathers using a pool in
a given time, the amount of disinfected water added to the
pool during that time, and the bacterial purity of the pool.
He also drew attention to the undesirability of stagnant
water in a swimming pool, reasoning that continuous addition of disinfected water to a pool was more effective in
preventing bacterial build-up than was periodic addition of
disinfected water.
His overall concept was that by mea-
suring various aspects of the pool's operation one could
infer the bacterial purity of the pool water.
Again, field
studies showed that Fair had not developed enough factors
and their proportionate bearing on the bacterial purity of
the water.
It later became apparent that so many factors
were at work, that if a sufficient number of factors
affecting the amount and types of bacteria in swimming
23
pools were identified and quantitated the resulting model
would be so complex that bacteriological standards (direct
measurement) would be much easier.
This has been reaffirmed recently by Victorin {1974)
who attempted to correlate the indirect measurements of
a free chlorine, redox potential, permanganate number,
ammonium, nitrate and total nitrogen with various bacteria
counts.
While she found that redox potential was a better
indicator of bacteriological quality than free chlorine,
she still concluded that there were no substitutes for
bacteriological examinations.
Using the free chlorine measurements to infer bacterial quality has been one of the most persistent errors made
by pool operators.
Stovall and Nichols {1923) and Stovall,
Nichols and Vincent {1926) showed a direct-relationship in
the lab between number of bacteria per milliliter and the
amount of free chlorine as measured by the orthotoludine
test.
Robinton, Mood and Elliot (1957) suggested that
bacterial quality could be inferred on the basis of free
chlorine residual alone.
The County of Los Angeles Dept.
of Health relies solely on this measurement, having decided
on the basis of an informal study that if the free chlorine
residual met the State's standard of 0.4 ppm that the
bacteria would also meet the State's standard (Interviews
1978, 1979).
Unfortunately, the qualifications of the studies
24
relating free chlorine levels to bacterial levels studies
are often overlooked.
Stovall and Nichols {1923} and
Stovall, Nichols and Vincent (1926} showed a direct relationship between the number of bacteria and free chlorine
in a laboratory setting where other facts which could
affect the bacteriological quality of the water were controlled.
When these factors are not controlled the rela-
tionship is less predictable.
Robinton and Mood (1957}
qualified their suggestion to the maintenance of high free
residual chlorination {greater than 1.0 ppm}, coupled with
routine accurate titrations of chlorine residuals.
Their
conclusion did not apply to pools which employed chlorination which they referred to as "marginal"
(greater than 0.4
ppm but less than 1.0 ppm free residual chlorine).
The
informal study by L.A. County should be totally discounted
since it was not a formal, scientific study and is not
supported by the literature.
Not only is there a lack of evidence that minimum
chlorination alone produces acceptable bacterial quality,
there is evidence that i t does not.
Victorin {1974)
described a swimming pool in Sweden in which the free
available chlorine was higher than 0.8 ppm in 82% of the
water samples taken but 55% of the samples failed to meet
Sweden's standard of not greater than 100 bacteria per
milliliter of water at 35°C.
It is clear that while the
r-----
25
free available chlorine level is one factor which affects
bacteriological quality,
work.
many
other factors are also at
Consequently the measurement of free available
chlorine in marginally chlorinated pools is inadequate by
itself in determining bacteriological quality of swimming
pool water.
Bacteria as Indicators
It has already been shown that bacteria are considered
the best indicators of bacteriological quality but investigators have long disagreed over which type of bacteria is
the best indicator of the water's potential for disease
transmission.
Coliforms were already in use as indicators of drinking water purity when the need for an indicator organism of
swimming pool water was felt.
Many lawmakers and scien-
tists simply applied the test for coliforms to the swimming
pool to determine the bacteriological quality of the water.
Several researchers have criticized the use of
coliforms as indicators in swimming pools.
Mallmann (1928)
claimed that coliforms were unreliable and suggested that
streptococci were preferable as a constant indicator of
intestinal pollution.
This proposal was supported by
Mallmann (1935, 1962), France and Fuller (1940) and Horwood, Gould and Shwachman (1933) •
These studies led to
the inclusion of tests for fecal streptococci ih Standard
'
'
26
Methods .•. l4th edition (1975). However, due to their higher.
survival rate in chlorine, their presence in water is to be
considered as supplementary data only.
It is not recom-
mended to use only the fecal streptococci to determine
water quality.
Also, since media currently in use are not
sufficiently selective, fecal streptococci should be
ch~r­
acterized biochemically to eliminate the possibility of
predominance by the non fecal Streptococcus
liquefaciens.
fa~lis
var.
These drawbacks indicate that testing for
fecal streptococci as an indicator of bacteriological
quality of swimming pool water is not preferred to testing
for coliforms.
The test for fecal streptococci is more
difficult to perform and less reliable for indicating water
quality.
Other investigators have proposed that Staphylococci
~
be used as indicators of bacterial quality.
Ferramola
and Elena Durieux (1951) were among the first of these.
Favero, Drake and Randall
(1964) after a two year study,
declared that the present standards (utilizing coliforms
and total bacteria count) were inadequate, and proposed a
standard of not greater than 100 staphylococci per 100 ml.
in any sample.
They concluded that staphylococci ... "are
valid indicators of pollution derived from the mouth, nose,
throat, and skin surfaces of bathers and are obviously of
concern since they are potential pathogens.
are more chlorine resistant than
~oliform
Because they
bacteria, the
27
absence of large numbers of staphylococci implies the
absence of intestinal bacteria."
Following the same
reasoning, Keirn and Putnam (1968) advocated the standard
of not greater than 30 staphylococci per 100 ml. in 15
percent of all samples. Villa and Zaffino (1970) advocated
the use of both coliform and staphylococci as indicators.
The position of those advocating the use of staphylococci as an indicator has been attacked and discredited by
two studies.
The Report (1953) by the Public Health
Laboratory Service (Great Britain) and the study by Crone
and Tee (1975) basically charged that staphylococci were
unsatisfactory indicators due to high resistance of staphylococci to chlorine.
It can be concluded from the literature reviewed that
no bacterium that has been suggested as an indicator has
been found entirely satisfactory.
The total count or
Standard Plate Count at 35°C has been used to evaluate the
disinfection process but cannot be used alone since a high
count would not necessarily indicate the presence of
pathogens.
The potential for pathogen transmission
probably is best determined by counts of total staphylococci.
Fecal contamination is best indicated by a fecal
coliform test.
Total coliform measurements may also be
used and are necessary to determine compliance with the
standards set by the State of California.
Tests for
28
specific pathogens are also available.
Pseudomonas
aeruginosa is a pathogen for which a Standard Method
(tentative) exists.
The most complete bacteriological
survey of a swimming pool would include all these tests.
The State of California has set standards on the results
of two tests, the Standard Plate Count (35°) and the total
coliform count as determined by the multiple tube fermentation technique.
REDUCING THE NUMBERS AND TYPES OF BACTERIA
Since swimming pools have long been suspected in the
transmission of disease, attempts have been made over the
years to reduce the number of bacteria in the water with
attention particularly paid to reducing the numbers of
pathogenic bacteria.
This reduction has been accomplished
by two general means;
(a) prevention, and (b) treatment.
Prevention refers to methods employed to prevent bacteria
from entering the pool.
Treatment refers to methods 'tvhich
kill, deactivate or remove bacteria which are in the water.
Prevention
Bacteria enter the pool water by three main routes;
(a) the bather,
(b) dropped in from the air, and (c) those
brought in by the water supply.
A fourth route with
potentially serious implications is the introduction of
bacteria by vandals who throw objects, including feces, at
patrons or pool employees.
These objects often end up in
29
the pool water.
As it is extremely difficult to prevent the introduction of bacteria by the air or by vandals, it is not
surprising that prevention has concentrated on reducing
contamination by the bather and by the water supply.
Reducing contamination brought in by the swimmer is the
most complicated of these.
One of the most important preventative measures is
denying entrance to swimmers with infectious diseases.
Washing bacteria from swimmers is another important
preventative measure.
Kroeber (1976) called showering
before swimming the "cardinal rule of sanitation."
For
years, most researchers have agreed on the importance of
the shower in reducing bacteria brought into the pool by
swimmers.
Robinton and Mood (1966) found that showering
reduced counts of staphylococci even though it seemed to
have no significant effect on faecal organisms.
Kroeber
(1976) adds that showering reduces the amount of free
ammonia and organic matter both of which can cause the
production of chloramines.
Chloramines retard the quick
killing power of free chlorine.
Luehring (1939) stated
that the shower must be warm with soap provided in order
to encourage a thorough shower, the logic of this is still
recognized today.
While showering is primarily designed to wash off
bacteria and organic matter brought to the swimming faci-
30
lity by the swimmer, other precautions are necessary to
keep the swimmer's body clean after the shower.
Keeping
the swimmer clean is accomplished primarily through keeping the facility clean.
Floors and decks which the swimmer
will walk and lie on should be kept clean.
Properly
cleaned and supplied toilet facilities are also important.
Lack of toilet paper or wet toilet paper in the restroom
can be expected to result in a deterioration of the bacteriological quality of the pool's water.
The problem of reducing the bacteria in the swimming
pool's water supply to acceptable levels is most often
bypassed by utilizing water from the municipal supply to
fill the pool and provide make-up water.
Treatment
The killing, deactivation or removal of bacteria found
in swimming pools has been effected by two general means:
i) Chemical and ii) Physical.
Chemical treatment refers to
the addition of chemicals to swimming pool waters.
These
chemicals are either known to or believed to deactivate or
kill some or all of the bacteria in the pool water.
Physi-
cal means are usually designed to remove visible debris or
turbidity from the water but bacteria can also be removed
by these means.
i)
Chemical -- Stokes and Thomas (1905) tested
copper sulfate as a disinfectant in swimming pool water.
They found that copper sulfate was only effective in
31
reducing the bacterial content of water that was already
fairly pure.
This drawback was so serious that copper
sulfate has not been considered since as a swimming pool
disinfectant.
Bunker (1910) ushered in the use of chlorine compounds as disinfectants in swimming pools when he demonstrated considerable reductions in bacterial counts by the
addition of 0.5 ppm of calcium hypochlorite.
This chemical
was used in early practice to provide intermittent disinfecting of pools.
The usefulness of calcium hypochlorite
was confirmed by several authors in the early literature
(Lewis in 1911, Burrage in 1911, Tully in 1912, Stovall
and Nichols in 1917 and 1923).
High test calcium hypo-
chlorite (HTH), which provides 70% available chlorine,
continues to be widely used as a pool water disinfectant
to this day.
.Hany L.A. City-operated pools used HTH
exclusively for days at a time in the summer of 1978.
Mannhiemer (1917) noted that chlorine gas, which
provides 100% available chlorine, was effective in disinfecting swimming pool water.
Stovall and Nichols (1923)
found that when using chlorine gas without pH control, a
residual of 0.1 ppm was effective in controlling bacterial
levels.
This low residual was effective but since chlorine
gas and water combine to form hydrochloric acid which is
undesirable in that it corrodes equipment and causes eye
irritation some type of pH control was necessary.
There-
32
fore, the 1926 APHA Joint Committee on Bathing Places
recommended that pools be kept at an alkaline pH.
They
suggested that soda ash be used to maintain an alkaline pH
when chlorine gas was being used as the disinfectant.
Mallmann and Cary (1933) found that high pH decreased the
bactericidal effect of chlorine, so it was suggested that
swimming pool water be maintained at only mild or moderate
pH.
Fletcher and Clark (1933) found that by combining
ammonia gas and chlorine gas to form chloramines, eye
irritation was eliminated and the chlorine residual was
maintained for a longer period of time, thereby economizing
the use of chlorine.
Unfortunately, Mallmann and Cary
(1933) and Fletcher and Link (1933) found that chloramines
were much less bactericidal than free chlorine.
Mallmann
and Cary's study was repeated by Chanlett and Gotaas (1942)
with similar results and the use of chloramines as disinfectants was abandoned.
Miller et al (1942) found that lime could be substituted for soda ash to regulate the pH of water treated with
chlorine gas.
It had been necessary to find a substitute
because soda ash was not capable of maintaining adequate
pH and chlorine levels in waters of low ppm total hardness
(soft waters).
Sodium hypochlorite, containing 5-15% available
chlorine, has also been used for many years.
Humphrey
33
(1978) regards this liquid as inferior to chlorine gas due
to its unstable properties.
Most L.A. City operated pools
use this liquid as their primary source of chlorine.
No matter which form of chlorine is used, be it
chlorine gas, sodium hypochlorite (liquid) or calcium
hypochlorite (solid), i t has been found that free available chlorine is a better bactericide than combined
chlorine (JI.1ood 1950).
By 1953 Mood had found that break-
point chlorination was desirable in maintaining water of
high bacteriological quality.
Be found that optimum
disinfection occurred by maintaining high free chlorine
residuals (1.0 to 3.99 ppm) and high pH (8.0 to 8.9).
Many other products have been suggested as disinfectants in swimming pools such as bromine gas, "Di-halo" a
solid form of bromine
in combination with chlorine and a
stabilizer, cyanuric acid and chlorinated isocyanurates,
and ozone.
Bromine and its derivatives are probably the
most promising of these.
None of these is reviewed here
as they do not apply to any L.A. City operated pool.
ii)
Physical
Mannheimer (1917) applied ultraviolet
light (U.V. light) to swimming pools.
Walker (1922) com-
pared the plate counts from a pool with and without the use
of ultra violet
light.
He only found a small reduction in
numbers of bacteria after use of the
u.v.
light.
As with
ozone, U.V. light has no residual effect and bacteria
introduced into the pool can remain in the water for quite
34
some time before being treated.
The APHA Joint Committee
on Bathing Places in its 1926 report recommended that
ultraviolet light not be used.
The use of filters to improve the esthetic and microbial quality of swimming pool water is nearly universal
today.
In fact, swimming pools are often much less turbid
than the municipal supply from which they draw their water.
Early swimming pools were not really anything more
than giant community bathtubs which were drained periodically and scrubbed thoroughly and refilled.
dubbed "fill and draw pools."
These were
Bunker (1910) related that
Brown University, in 1903, equipped its swimming pool with
a gravity sand filter.
Due to repeated clogging, it was
replaced in 1908 with a six foot crushed rock and sand
filter designed to filter all the water in the pool every
ten hours.
The application of filters to swimming pool
water provided
cleaner water with less waste due to the
recirculating feature.
Today many types of filters are used in swimming
pools:
pressure sand-and-gravel filters, gravity sand-and-
gravel filters,
"High-Rate" pressure sand filters, anthra-
cite filters, vacuum diatomaceous earth filters and pressure diatomaceous earth filters.
In Los Angeles City pools
pressure diatomaceous earth filters are the most widely
used although pressure sand-and-gravel filters are still
used in many of the older pools.
35
Another method of physical removal of bacteria relies
on removing the surface film and floating debris from the
water.
This is accomplished by use of scum gutters or
skimmers.
Amies (1956) theorized that the body oils on the
surface of the water would combine with the chlorine and
protect the bacteria on or in this film.
Scum gutters
were originally developed for expectoration, overflow
prevention and as handrails (Farnham 1910, Constant 1908,
Bliss 1918, Beaufield 1919 and Viterbro 1919).
All L.A.
City operated pools are equipped with scum gutters.
A proper water level is essential to the correct use
of scum gutters.
Low 'iorater levels can entirely eliminate
the effectiveness of these gutters in removing debris and
surface film.
A final method of physical treatment is vacuuming or
sweeping the pool bottom regularly.
This removes any
organic or inorganic material and the bacteria associated
with them which are lying on the pool bottom.
Algae control, whether physical or chemical, has an
indirect effect on the bacteria in the water to the extent
which algae are able to place competitive demand on the
disinfectant.
Review
The operation of a swimming pool must undergo constant
review to determine that all systems are operating proper-
36
ly.
Review should be made constantly by the operator, and.
periodically by the health authorities.
The operator
should be able to recognize and correct difficulties as
they occur.
Also, it is important that the operator
does not hesitate to close the pool when the treatment
facilities are not functioning properly.
The public health officer (PHO) is also charged with
maintaining the health of pool patrons.
The PHO should
make certain that the pool operator is taking the proper
preventative and treatment measures in the pool's day to
day operation.
inspection.
This is usually accomplished by regular
An inspection should include examination of
the water in the pool, an examination of the facility and
an examination of the pool's operational procedures.
CALIFORNIA LAWS AND REGULATIONS RELATING TO SWIMMING POOLS
( 19 7 4)
California led the nation in 1919 by being the first
state to develop sanitation standards for swimming pools.
The latest revision of these laws was made in 1974.
These
standards specify methods to prevent bacterial contamination of the pool and methods to disinfect and remove
bacteria that enter the water.
Excessive amounts of bacteria and particularly pathogenic bacteria are to be prevented from entering the pool.
37
This is to be accomplished by several tactics which include:
1.
Excluding patrons suspected of being afflicted
with an infectious disease, cough, cold or sores or
bandages, except on presentation of a written statement of
current date as approved by the health officer.
2.
Providing warm showers and soap so that the patron
will be relatively clean when entering the water.
3.
Providing complete toilet facilities with soap,
running water and toilet paper.
4.
Using only water from an approved source.
5.
Requiring that the whole pool area shall be kept
clean, sanitary and free of litter and vermin.
Once bacteria have entered the pool they are to be
controlled by disinfectant and removed from the water.
Tactics which facilitate these goals include:
1.
Floating scum, sputum and debris are not to be
allowed to accumulate in the pool; water levels must be
maintained so that overflow gutters can remove such
material.
The bottom and sides of the pool shall be
cleaned as often as necessary to keep them in a clean
condition.
2.
Requiring proper design of inlets and outlets so
that proper circulation can be achieved, eliminating
stagnant areas.
3.
Requiring that every swimming pool be equipped
38
with an overflow gutter and/or skimmer capable of continuously withdrawing at least 75% of the required recirculation capacity to provide continuous skimming of the surface.
4.
Requiring that every swimming pool be equipped
with a filter that has been proven to maintain clear water
under anticipated operating conditions.
5.
Requiring that every pool be equipped with a
residual disinfectant feeder which must meet certain
requirements.
When chlorine is used, such equipment
must be used to maintain a free chlorine residual of
at least four-tenths
(0.4) ppm throughout the pool when-
ever it is open or in use.
6.
Since pH affects the bactericidal effect of
chlorine it is required that the pH be maintained between
seven and two-tenths (7.2) and eight and four-tenths (8.4).
7.
Pool water so turbid that a black disc, six inches
in diameter, on a white field, when placed at the bottom of
the pool at the deepest point is not visible from all
distances up to ten yards from the disc shall be considered
as evidence that the recirculation and purification systems
are not operated and/or maintained properly.
Such pools
shall be closed and shall not be reopened until the water
is clean and clear, and upon specific approval of the
health officer.
If these rules, designed to minimize bacteria in the
39
pool, are followed it is hoped that a clean pool which
meets the State standard for bacteriological quality of
swimming pools will result.
Title 17 section 7825 of the
California Health and Safety Code (1974) states in part
that:
"Bacteriological quality of water in the pool
shall be such that not more than 15 percent
of the samples covering any considerable
period of time shall
(a) contain more than 200 bacteria per
milliliter, as determined by the
standard (350C) plate count, or
(b) show positive test (confirmed test) for
coliform organisms in any of the five
10 milliliter portions of a sample, at
times when the pool is in use."
SUMMARY
This review of the literature has shown that \..rhile
swimming pools are instrumental in the transmission of
certain diseases, the scarcity of epidemiological evidence
suggests that the extent of their responsibility for many
diseases has probably been
overestimated.
Still, the
actual extent of the problem is unknown, and the swimming
pool should continue to be treated for what it is, a
potential location for disease transmission.
The potential for disease transmission can be reduced
by a three part program of prevention, treatment and review.
Prevention keeps bacteria out of the water, treat-
ment removes or kills the bacteria which gain entry to the
water and review is necessary to receive feedback that the
40
systems utilized in prevention and treatment are being
properly managed.
CHAPTER III
METHODOLOGY
PRELIMINARY STUDY
Collection
The manager of each of the pools operated by the City
of Los Angeles was contacted by telephone during the month
of July, by the author.
The author was presented to them
as a fellow Pool Manager and as a graduate student at California State University Northridge (CSUN).
The anonymity
of their answers and the researcher's permission from the
Aquatics Director was thoroughly assured.
This being done,
they were asked if they would participate in the study.
If
they answered affirmatively, the list of questions (Appendix I) was read to them and their answers recorded.
Analysis
The collective answers to each question were assembled
for information only.
Pools for the bacteriological study
were selected on the basis of the manager's willingness to
cooperate (Question #23) and the availability of a refrig. erator to the manager (Question #22), with some consideration also being given to distance from freeway, main routes
or other pools to be sampled.
41
42
BACTERIOLOGICAL STUDY
Collection
The procedures to be used for collecting samples for
bacteriologic examination are specified in Standard
Hethods for the Exarriination of Water and Wastewater 14th
edition (1975).
These procedures specify how the collec-
tion containers are to be cleaned and dechlorinated, and
how the sample is to be collected.
As specified in "Standard Methods .•• " the 250 ml.
glass bottles intended for the collection of water samples
were cleansed before use.
Alconox, a laboratory glassware
cleaner was used with hot water followed by extensive hot
water rinsing and a final rinse with cold distilled water.
After cleaning, a dechlorinating agent was added to
the clean bottles.
This was necessary to neutralize any
residual chlorine, preventing a continuation of the bactericidal action of the chlorine during the time the sample
is in transit to the laboratory.
In this way the bacterio-
logic examination is able to indicate more probably the
true bacterial content of the water at the time of
sampling.
Sodium thiosulfate was used as a dechlorinating agent.
By adding 1 ml. of a 2% solution of sodium thiosulfate to a
250 ml. bottle a final concentration of at least 80 ppm
was
insured.
The bottle was then capped and autoclaved
at 121 C for 15 minutes.
43
These cleaned, autoclaved bottles containing sodium
thiosulfate were delivered to the pool managers who did the
actual sample collection.
In order to standardize the
methods used by the various managers in collecting samples,
several steps were taken.
First, all managers involved in this study received a
photostatic copy of pages 904, 976 and 977 of Standard
Methods ... (1975).
This is the section outlining sample
collection procedures. Relevant sections were underlined.
Second, attached to the photostatic copy of these
pages of Standard Methods, was a review of the salient
points plainly written.
This read as follows:
When Filling the Water Bottle
1.
Sample during and in the area of greatest bather
load after 3:00p.m., record time of collection.
2.
Open bottle only at the last minute and please
avoid touching the inside of the cap to anything.
3.
Hold bottle at base, not the neck and with the
mouth down, submerge the bottle.
4.
Tilt the bottle so that the neck points up and
move the bottle forward away from your hand to fill bottle.
5.
Do not fill to the brim-- please leave at least
one inch of air space.
6.
Replace cap immediately and refrigerate.
Third, the written information was discussed individually with each pool manager and the desired procedure
44
demonstrated.
Fourth, every refrigerator to be used was adjusted to
approximately 4.5°C using a Springfield freezer thermometer, a note was placed next to the termperature adjustment knob requesting that the adjustment not be altered.
Also each refrigerator was checked with the same thermometer every ten days to check for changes in temperature.
Any temperature variation above 0°C but below 10°C was
tolerated.
Finally, once every two weeks each pool was visited
during operating hours and observations made on sampling
procedures.
During this visit attention was always placed
on the importance of careful and representative sampling.
Each night, a filled bottle would be taken from the
refrigerator and replaced by a sterile bottle containing
the premeasured quantity of sodium thiosulfate.
The filled
bottle was then placed in a Coleman ice chest containing
seven pounds of frozen "Blue Ice"
(registered trademark,
a product of Divajex) and then transported to the CSUN,
Environmental Health Laboratory for analysis.
Analysis
Upon arrival in the lab all sample labels were first
examined to determine if six hours or more had elapsed
since collection.
Samples collected more than six hours
earlier were discarded. Samples collected less than six hours
45
earlier were analyzed for the total coliform bacteria using
the multiple tube fermentation technique and for total
bacteria growing at 35°C using the Standard Plate Count
(SPC) procedure.
The Multiple-Tube Fermentation Technique was performed
as outlined in Standard Methods ••• each sample bottle was
properly shaken and five, 10 ml. portions were aseptically
removed and added, one portion each, to five test tubes
containing lauryl tryptose broth and an inverted "Durham"
These test tubes were then incubated at 35 ±
type tube.
0.5°C for 24 and 48 hours.
This is known as the presump-
tive test.
Primary fermentation tubes showing any amount of gas
at the end of 24 or 48 hours were considered positive for
the presumptive test and were submitted to the confirmed
test. The confirmed test is performed by inoculating fermentation tubes containing brilliant green bile broth, with
a wire loop from the positive presumptive tube. These tubes
were then incubated at 35 ± 0.5°C for 48 ± 3 hours.
The
presence of gas in the inverted vial at the end of the 48
hour period constituted a positive confirmed test.
While not required by law and not required by the
experiment, a streak plate on Levine's Eosin Methylene Blue
Agar was made from each tube of brilliant green bile broth
showing gas.
2 hours.
These were incubated at 35
± 0.5
C for 24 +
The colonies developing were described as typical
46
(nucleated with or without metallic sheen); atypical
(opaque, unnucleated, mucoid, pink after 24 hour incubation), or negative (all others).
No further attempt at
characterization was made.
The Standard Plate Count procedure was also performed
as specified in the 14th edition of Standard Methods for
the Examination of Water and Wastewater (1975).
Disposable petri plates were marked with necessary
information.
Duplicate plates for each dilution of each
sample were prepared.
Samples were thoroughly mixed as specified. Duplicate
portions of 1 ml. and 0.1 ml. were aspetically transferred to
the petri plates from each sample bottle. Mel ted plate count
agar tempered in a hot water bath to between 44 C and 46 C was
added to the sample and mixedo The plates were allowed to
solidify and were incubated at 35°C
:t 0. 5 C for 4 8
±3
hours.
After incubation the colonies on the surface of the
medium of each plate were counted and recorded according to
the procedures specified in Standard Methods ... (1975).
additional procedure was followed.
One
One plate from each
batch was selected at random and the colonies recounted.
If the second count differed by more than 5% from the first
count all plates were examined twice more with the middle
count being taken.
This procedure was designed to minimize
personal counting errors.
Sterility Controls were performed on each lot tested.
47
This consisted of simply pouring two agar blanks into petri
plates as controls to check the sterility of the agar and
plates.
Also, any air entering during the pouring process
could introduce bacteria.
CHAPTER IV
RESULTS
PRELIMINARY STUDY
Forty-two of the forty-six (91%) pool managers
con~
tacted agreed to participate in the telephone survey.
The
questions and the compiled answers of the managers are
given below:
QUESTION 1:
In your opinion, is the water in your pool
unsanitary greater than 15% of the time?
Please use your own definition of the word
"unsanitary."
ANSWER 1:
19 managers said yes (45%) .
23 said no (55%).
QUESTION 2:
What is the average daily attendance at your
pool?
ANSWER 2:
The answer given was divided by the pools
rated capacity and the results compiled in
Table 1.
QUESTION 3:
Do you regard operating with a chlorine
count below 0.4 ppm as a daily occurrence?
ANSWER 3:
26 managers said yes (62%}.
16 said no (38%).
QUESTION 4:
Do you regard operating with no measurable
chlorine count as at least a weekly occurrence?
48
49
ANSWER 4:
18 managers said that they did (43%).
24 replied that they did not (57%).
QUESTION 5:
When you obtain a chlorine count below 0.4
ppm do you estimate and record a lower count
or do you record a value greater than that
actually obtained?
ANSWER 5:
20 managers said they would report a higher
number (47.6%}.
20 managers said they would estimate and
record their estimated value (47.6%).
2 managers refused to reply to this question
(4.8%).
QUESTION 6:
How many times per day is the chlorine in
your pool tested with a test kit?
ANSWER 6:
(See Table 2) .
QUESTION 7:
When the deep end clouds up so that you cannot see the bottom of the deep end from the
deck, what do you do?
(a)
Instruct lifeguards to pay special
attention to swimmers in deep water
during this period.
(b)
close the deep end to swimming and
diving but leave the shallow end open.
(c)
Close the entire pool.
(d)
Question doesn't apply.
(e)
Do nothing.
50
TABLE 1
Attendance Profile
Attendance
Capac1ty
15
25
35
45
55
65
75
85
95
105
115
125
135
-
X
# of Pools
100
25
35
45
55
65
75
85
95
105
115
125
135
145
4
1
3
8
3
6
3
5
4
1
1
1
2
TABLE 2
Chlorine Test Frequency
Average # of Chlorine
Checks/Day
0
1
2
3
4
5
6
7
# of Pools
5
13
7
6
5
5
0
1
51
ANSWER 7:
2 managers would instruct lifeguards to pay
special attention to the swimmers in deep
water during this period (4.8%).
35 managers said they would close the deep
end to swimming and diving but leave the
shallow end open (83.3%).
1 manager would close the entire pool (2.4%).
4 managers didn't think the question applied
to their pools (9.5%).
QUESTION 8:
When using the test kit, would you say that
the test cell is rinsed after each use or are
the contents simply poured out before the
next use?
ANSWER 8:
20 managers believed that the test cell was
rinsed before each use (47.6%).
21 managers said that the contents were
simply poured out before the next use
(50.0%).
1 manager said that the test cell is never
used at his pool, so the question was not
applicable (2.4%).
QUESTION 9:
Is your pool provided with working toilets
and showers?
ANSWER 9:
42 managers said yes (100%}.
QUESTION 10:
Do those showers provide at least warm water
or is only cold water provided?
52
ANSWER 10:
16 managers said that warm or hot water was
provided (38%).
26 managers said that only cold water was
provided (62%).
QUESTION 11:
Is soap provided in these showers?
ANSWER 11:
32 managers said no soap was provided (76%).
10 managers said soap was provided (24%).
QUESTION 12:
Do a majority of the patrons at your pool
take a rinse shower before swimming?
ANSWER 12:
25 managers said yes {60%).
17 managers said no (40%).
QUESTION 13:
Do you keep your pool's water level high
enough to provide constant overflow into the
scum gutters?
ANSWER 13:
28 managers said that they kept the level
high enough to provide constant overflow
(67%).
14 managers said that they did not keep the
water level that high (33%).
QUESTION 14:
Has your chlorinator been working properly
this summer?
ANSWER 14:
24 managers said yes, their chlorinators had
been working properly (57%).
18 managers said that their chlorinators had
not been working properly (43%).
QUESTION 15:
How would you characterize the amount of
' .
53
algae in your pool?
ANSWER 15:
(a)
none
(b)
small
(c)
moderate
(d)
excessive
21 managers reported no algae (50%).
12 managers reported a small amount of algae
(28.6%).
5 managers reported a moderate growth of
algae (11.9%).
4 managers reported an excessive amount of
algae (9.5%).
QUESTION 16:
Is toilet paper provided in the toilets in
your pool?
ANSWER 16:
40 managers said that toilet paper was
provided (95%) .
2 managers said that toilet paper was not
provided (5%).
QUESTION 17:
Does anyone on your staff have the responsibility of checking patrons for infectious
diseases, coughs, colds, sores, rashes and
banda ids?
ANSWER 17:
13 managers felt that this was a responsibility held by someone on the pool staff
( 31%) .
29 managers felt that no staff member was
54
responsible for checking patrons for these
conditions (69%) •
QUESTION 18:
Would you allow a person known to be, or
suspected of being afflicted with an infec=
tious disease use the pool without them
presenting a note from the doctor?
ANSWER 18:
41 managers said that they would not allow a
person with an infectious disease to use
the pool (98%) •
1 manager said that he would allow such a
person to use the pool, without a doctor's
or health officer's note, if he knew that
the disease could not be spread to other
patrons in the pool (2%) •
QUESTION 19:
Would you allow a person suffering from a
cough or cold to use the pool without presentation of a doctor's or health officer's
note?
ANSvVER 19:
31 managers said that they would not exclude
a person suffering from a cough or cold
from the pool (74%) .
7 managers said that they would exclude such
a person unless presented with a note from
a doctor or health officer (17%).
4 managers refused to give a yes or no
answer, saying that they used their judg-
55
ment to determine whether or not the cold
or cough was serious enough to warrant
excluding the patron from the pool (10%) .
QUESTION 20:
Would you allow a person suffering from sores
or wearing a bandaid to use the pool without
presentation of a doctor's or health officer's note?
ANSWER 20:
16 managers said that they would exclude a
person with sores or wearing bandaids (38%).
15 managers said that it depended on the
individual case (36%).
11 managers said that they would not exclude
such a person (26%).
QUESTION 21:
Does your maintenance man, who is responsible for maintaining the filters, do a
great, good, fair or poor job?
ANSWER 21:
9 managers said that the maintenance man did
a great job (21%).
25 managers said that he did a good job (60%).
7 managers said he did a fair job (17%).
1 manager said that the maintenance man did
a poor job (2%) •
QUESTION 22:
Do you have access to a refrigerator at or
near your pool?
ANSWER 22:
16 managers said that they had access to a
refrigerator (38%).
56
26 managers did not (62%) •
QUESTION 23:
If selected would you participate in a bacteriological examination of your pool's
water?
ANSvmR
23:
42 managers said that they would participate
if selected (100%).
BACTERIOLOGICAL STUDY
The results of the daily pool water sampling
will be found in Appendix 2.
These results are summarized
in Table 3.
TABLE 3
Bacteriological Study:
% of samples with
Accumulated Results
greater than 200
bacteria/ml
% of samples showing positive test (confirmed test)
in any of five 10 ml portions
A
5%
5%
B
40%
10%
c
55%
25%
D
30%
10%
E
24%
14%
F
73%
18%
G
25%
4%
H
52%
52%
I
20%
10%
J
22%
4%
Pool
CHAPTER V
SUMMARY AND CONCLUSION
Nine out of the ten pools exceeded 200 bact/ml more
than 15% of the time.
Three of the ten pools exceeded one
(of 5, 10 ml tubes) positive, confirmed tube greater than
15% of the time.
Only one pool met both parts of the
bacteriological standard set by the State.
null hypothesis is accepted.
Therefore the
Pool F had the highest
percent of violations in total bacteria (73%).
Pool F
also had the largest surface area and the worst circulation system in the study.
Pool H had the worst percentage
of positive total coliform (confirmed test) tests (52%).
Pool H reported an alarming tendency on the part of vandals
to throw feces into the pool, so this high violation rate
may be explained on that basis.
The overall high violation
rate is believed to represent a serious potential health
hazard.
The answers which the managers give in the preliminary
survey seemed to indicate a severe lack of awareness of
the content and intent of the State laws regarding swimming
pool sanitation.
It is felt that the widespread violations found in
this study can be attributed to the non-utilization of
reasonable programs of prevention, treatment and review.
57
58
Summary and Discussion of the Biases in the Study
To aid in the interpretation of the results of both
the preliminary study and the bacteriological study, these
areas of potential bias are delineated.
In the preliminary study, some managers may have
purposely answered so as to make their pools seem to be
better managed than was true or refused to answer.
This
type of behavior may have been motivated by a fear that
their anonymity would not be preserved.
Other managers
may have purposely answered so as to make their pools
seem to be managed worse than was true.
This type of
behavior may have been motivated by anger at the seeming
lack of support by the Aquatics Office (as stated previously, the L.A. City pools experienced chlorine supply
deficiencies during the summer of 1978).
Still other
managers may have unintentionally given erroneous answers.
Establishing the credibility of the interviewer and
the importance of the survey were the key elements used
to combat erroneous answers.
Still, it is expected that
these type of results are widely variable and as such
give only a sketchy picture of most aspects of pool operation.
Bias may have been introduced by the method of
selecting pools for the bacteriological study.
Again,
managers '"hich refused to take part in the study may have
been afraid of showing poor results.'·. Pools with refrig-
59
erators may have been different than pools without refrigerators.
Pools being frequented by different cultural
groups may show different amounts and types of bacteria in
the water.
So few managers refused to participate in the interview (four of forty-six or 9%) that this factor was minimized.
The availability of refrigerators is considered a
random factor.
Cultural and geographic differences were
minimized by selecting two pools from each of the five
geographic areas designated by the City (Valley, South,
East, West and Central).
Another potential cause for bias was sensitization
of the various pool staffs to sanitation measures.
This
sensitization was mentioned by several pool managers who
noted that they were much more interested in their water
quality since they had been involved in this study.
Such
sensitization would presumably lead to better maintenance
of the water.
On the other hand, the necessity of having the pool
manager sample the water may have led to artificially
contaminated samples and artificially high results.
For
this reason, much effort was made to standardize the
sampling procedure.
Sampling near the water jets could
result in samples containing less bacteria per ml than in
the rest of the pool.
Still, by standardizing sampling
procedure, which directed only that the sample be taken
60
in the area of greatest bather load and at the time of
greatest bather load as specified in Standard Methods •.•
(1975), the effect was to randomize the sampling site in
relation to the water return jets.
It is felt that while it certainly would have been
preferable to have trained researchers do the actual
sampling, the training of the pool managers in sample
collecting was sufficient to assure their ability to do
the job properly.
It is felt that the results of the bacteriological
study are a fair representation of the actual conditions
at these pools.
CHAPTER VI
DISCUSSION
In an attempt to reduce the likelihood of swimming
pool water acting as a vehicle in disease transmission,
the State of California has enacted several laws.
These
laws provide for preventing bacterial contamination (prevention), treating the water to reduce the degree of contamination (treatment), and review of the pool operation
(review) •
While the preliminary study is presented for information only, this information can be used to identify
potential weaknesses in the application of particular
tactics used to achieve prevention, treatment and review.
It should be noted that, in an attempt to encourage
honest answers, the managers were promised complete
anonymity.
Therefore, the answers to most questions
are not verifiable.
Nonetheless, these answers should
provide persons interested in reducing the numbers and
types of bacteria in swimming pools with information which
it is hoped will aid them in developing more effective
application of programs of prevention, treatment and
review.
PREVENTION
No one in the near future is likely to advocate that
61
62
all pools be built indoors, with forced, treated air, to
reduce bacteria in the water.
That would be expensive
and probably nearly fruitless from the infectious disease
prevention point of view.
On the other hand, contaminated
incoming water has been implicated in disease transmission.
Therefore, all L.A. City pools use only water from
the municipal supply, water which is already of drinking
water purity.
By elimination of choices, reducing the bacteria
brought in by the swimmer stands as the primary tool of
prevention.
This reduction of bacteria is effected by
two general means:
1) excluding from all public bathing
places any person " ••• known to be, or suspected by the
health officer or management of being afflicted with an
infectious disease, suffering from a cough, cold, or
sores, or wearing bands or bandages ••• " and 2) cleanliness which applies to the patron and to the facility.
The preliminary survey showed that only 3 (7%) of
the managers interviewed would exclude patrons under
every provision of section 7830 as cited above.
The fact
that 42 (98%) of the managers interviewed said that they
would exclude someone with an infectious disease is
encouraging.
However, since 31 (74%) would not exclude
someone with a cough or cold (and in the face of a
separate mention made in the law) it is thought that
coughs and colds are not considered infectious diseases
63
by the pool managers.
Actually, the use of the term "infectious disease"
in the state law is unfortunate.
"Communicable disease" is
a term preferred by most health officials (Ehlers and Steel
1965).
Perhaps a clarification by the State of these terms·
would aid the pool manager in understanding who is to be
excluded and on what grounds.
The second horn of prevention is cleanliness.
The
State does not require the patron to take a shower before
entering the pool.
It does allow the health officer to
require " ••• posting of notices directing the bathers to
make use of the toilets and showers before entering the
pool."
The law also mandates that hot water showers and
soap be provided.
The shower is probably the most neglected aspect of
cleanliness.
Usually the public will not tolerate a filthy
facility, yet filthy patrons, using the pool as a bath, may
go unnoticed.
Only 16 (38%) managers indicated that hot
water is available to the patrons and only 10 (24%) said
that soap was provided in the showers.
Only three (7%) of
the 42 managers interviewed were providing their patrons
with facilities for a hot shower with soap as directed by
State law.
This should be corrected by administrative
assistance in the form of providing that each pool is
equipped with a functioning water heater and a supply of
soap (preferably liquid).
64
While the value of a hot shower with soap in reducing
the amount of bacteria introduced into the pool seems
obvious, many managers have overlooked the value of a
simple rinse shower.
Since 17 (40%) of the managers re-
plied that the majority of the patrons of their pool did
not take even a rinse shower, the value of designing pool
buildings so that patrons must pass through the shower
before entering the pool is underscored.
Education of both
the pool manager and the patrons must also take place to
improve compliance with this common-sense rule.
TREATMENT
Chemical
The only chemicals used at most L.A. City operated
pools (two known exceptions) are sodium hypochlorite (515% available chlorine in liquid form) and high-test
calcium hypochlorite (a.k.a. HTH, 70% available chlorine
in a white granular solid form), only a few new pools use
chlorine gas with pH control.
The application of these chemicals is under the
direct control of the pool manager.
The job of the pool
manager in providing safety, crowd control, employee supervision, aquatic instruction, administrative paperwork and
meeting health provisions is often so demanding that the
chores considered non-immediate are put off.
Of these, meeting health provisions is probably
65
considered the least immediate by most managers.
A measure
of this is the manager's ease and facility in falsifying
records.
Twenty (47.6%} of the managers reported that they
falsified chlorine records to show adequate residual when
it was not adequate.
Only 11 (26.2%) of the managers said
that they took the time to measure the chlorine residual
with a kit, four time a day as is required by State law.
In fact, the kits issued to most pools, and the kit
used by the L.S. County sanitarians, the "Dial a Test" kit,
does not meet the State standard for test kits.
The State
law provides that the kit include a standard of 0.1 or 0.2
ppm, the "Dial a Test" kit only goes down to 0.4 ppm.
Furthermore, the residual which the State says should be
measured is the free chlorine residual.
These kits, with
instructions to add orthotoludine to a test cell of water,
shake, and compare colors, measure total chlorine, not
free chlorine.
It is suggested that the pool managers be taught the
importance of proper chlorine monitoring, that personal
errors be eliminated by the purchase and installation of
automatic chlorinators and that a more suitable method of
chlorine measurement be used.
the La Mette-Palin D.P.D. test.
One of the best methods is
Standard Methods •.• (1975)
also recognizes amperometric titration, two iodometric
methods, Stabilized Neutral Ortholudine Method (SNORT), leuco
crystal violet method, and the syringaldazine method (ten-
66
tative).
Standard Methods •.• (l975) does not recognize the
orthotoludine method.
While present State law does allow
for any method accurate to within plus or minus one-tenth
.(0 .1)
ppm, the difficulty in the properly performed ortho-
toludine method, of cooling the water to 1°C before adding
the orthotoludine (a procedure of which the County sanitarians, City pool operators and kit manufacturers seem ignorant) makes a switch to the D.P.D. method a good way of
increasing the accuracy and validity of chlorine measurements.
Physical
Again, most managers are fairly conscious of the
cleanliness of their facility.
The public is usually quick
to complain about omissions in this area.
The main area
for concern then is the failure reported by 14 (33%) of the
managers in keeping the water level high enough so that the
scum gutters can be effective in removing surface film and
debris.
Perhaps the more pleasant name of "overflow gut-
ter" misleads one as to the purpose of these gutters.
Again, education is necessary so that the purposes of this
device will be understood by those operating the pool.
REVIEW
This is probably the most important area, for through
reviE::w, prevention and treatment are maintained.
Wide-
67
spread ignorance of treatment and prevention is probably a
result of poor review procedures.
L.A. County no longer makes bacteriological tests,
mistakenly believing that a chlorine residual of 0.4 ppm
assures an acceptable level of bacteria, both total and
coliform.
When asked how often they measure total chlorine
residuals (with their improper kits they measure the larger
value of total chlorine, not free available chlorine residual) below 0.4 ppm, they didn't know.
They did estimate
that 50%, plus or minus five per.cent, of their inspections
warrant revisits due to some inadequacy in the pool.
It is felt that this high figure of revisits and the
high proportions of improperly operated pools and the
results of the bacteriological survey showing that nine of
ten selected pools could not meet the bacteriological
standards set by the State all point to incomplete and
inadequate procedures of review.
L.A. City and L.A. County need to emphasize education
of pool operators and implement a more frequent and thorough system of review.
The City could provide an inser-
vice training for managers that includes study of the
latest revision of Laws and Regulations Relating to Swimming Pools accompanied by intelligent explanation of the
reasons for such laws.
The County could provide the
Aquatics Section Supervisors with even more thorough
instruction.
'These supervisors visit each pool weekly,
68
and could be of great help to the pool manager by emphasizing the importance of applying proper measures of
prevention and treatment of pool water.
The County must
also question the adequacy of the present inspection
procedures.
Each pool should receive at least one thor-
ough inspection during operating hours each summer, and
chlorine spot checks are suggested twice a month.
manager (the author) with five
One
years experience has never
even heard of an L.A. City operated swimming pool receiving
a thorough sanitary inspection.
Finally, it is suggested that L.A. County resume
bacteriological testing of swimming pool water.
As was
shown in the literature review, this is the only known way
to determine that the bacteriological standards set by the
State are being met.
69
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79
APPENDIX I
Preliminary Survey Questionnaire
QUESTION 1:
In your opinion, is the water in your pool
unsanitary greater than 15% of the time?
Please use your own definition of the word
"unsanitary."
QUESTION 2:
What is the average daily attendance at your
pool?
QUESTION 3:
Do you regard operating with a chlorine count
below 0.4 ppm as a daily occurrence?
QUESTION 4:
Do you regard operating with no measurable
chlorine count as at least a weekly occurrence?
QUESTION 5:
When you obtain a chlorine count below 0.4
ppm do you estimate and record a lower count
or do you record a value greater than that
actually obtained?
QUESTION 6:
How many times per day is the chlorine in
your pool tested with a test kit?
QUESTION 7:
When the deep end clouds up so that you
cannot see the bottom of the deep end from
the deck, what do you do?
(a)
Instruct lifeguards to pay special
attention to swimmers in deep water
during this period.
80
(b)
Close the deep end to swimming and
diving but leave the shallow end open.
QUESTION 8:
(c)
Close the entire pool.
(d)
Question doesn't apply.
(e)
Do nothing.
When using the test kit, would you say that
the test cell is rinsed after each use or are
the contents simply poured out before the
next use?
QUESTION 9:
Is your pool provided with working toilets
and showers?
QUESTION 10:
Do those showers provide at least warm water
or is only cold water provided?
QUESTION 11:
Is soap provided in these showers?
QUESTION 12:
Do a majority of the patrons at your pool
take a rinse shower before swimming?
QUESTION 13:
Do you keep your pool's water level high
enough to provide constant overflow into the
scum gutters?
QUESTION 14:
Has your chlorinator been working properly
this summer?
QUESTION 15:
How would you characterize the amount of
algae in your pool?
(a)
none
(b)
small
(c)
moderate
81
(d)
QUESTION 16:
excessive
Is toilet paper provided in the toilets at
your pool?
QUESTION 17:
Does anyone on your staff have the responsibility of checking patrons for infectious
diseases, coughs, colds, sores, rashes and
bandaids?
QUESTION 18:
Would you allow a person known to be, or
suspected of being afflicted with an infectious disease to use the pool without them
presenting a note from the doctor?
QUESTION 19:
Would you allow a person suffering from a
cough or cold to use the pool without presentation of a doctor's or health officer's
note?
QUESTION 20:
Would you allow a person suffering from
sores or wearing a bandaid to use the pool
without presentation of a doctor's or health
officer's note?
QUESTION 21:
Does your maintenance man, who is responsible
for maintaining the filters, do a great,
good, fair or poor job?
QUESTION 22:
Do you have access to a refrigerator at or
near your pool?
QUESTION 23:
If selected would you participate in a bacteriological examinatiori of your pool'swater?
APPENDIX 2
Bacteriological Study:
AUGUST 3rd
A
SPC (bact/ml)
180
B
N
0
c
D
630
8
T
Presumptive
5
EMB
SPC standard
Confirmed
standard
4
3
Typ
+
R
0
c
POOL
F
;>3000
(control)
K
G
H
I
) 3000
350
' 10
2
2
0
0
0
0
X
X
J-
(lxlo-1 <lxlo-1
T
0
p
Confirmed
E
N
0
Daily Results
0
5
p
1
Atyp
X
X
E
4
R
0
X
c
X
Atyp
X
X
X
X
+
+
+
-
-
-
+
-
-
-
-
N
0
29
260
')3000
(lx1o-l
E
s
s
+
-
E
+
-
D
s
s
E
D
AUGUST 4th
SPC (bact/ml)
23
)3000
480
N
0
293
T
Presumptive
(# of +)
Confirmed
(# of +)
EMB
0
1
2
5
p
X
1
1
X
Typ
Atyp
R
0
c
0
1
0
1
0
R
0
X
-
X
0
X
c
X
X
X
X
X
-
+
+
+
-
-
-
-
-
-
p
5
Atyp
E
E
SPC standard
-
+
+
+
Confirmed
standard
-
s
s
s
s
+
+
E
+
E
D
1400
T
D
-
co
N
AUGUST 5th
SPC (bact/m1)
B
N
T
T
p
p
R
0
R
0
X
X
X
X
0
Presumptive
Confirmed
<lx10-
c
c
E
SPC Standard
s
s
s
s
Confirmed
standard
E
E
D
D
D
1
E
H
I
120
>3000
150
5
0
5
2
0
0
5
X
4
2
X
X
Atyp
X
Atyp
Typ
X
X
s
s
+
-
+
-
-
-
E
+
-
+
+
-
-
F
G
N
50
0
1000
K
J
(1xl0 -
1
l
1
T
0
E
EMB
c
A
N
0
0
p
-
-
-
-
R
0
c
E
D
----------
--·-----
-
AUGUST 7th
N
SPC (bact/m1)
0
5
10
l
0
<.1xl0- 1
T
Presumptive
Confirmed
R
0
0
X
X
EMB
c
X
X
X
SPC Standard
s
s
Confirmed
Standard
E
D
N
N
0
0
0
T
T
T
0
p
E
N
-
-
-
-
-
-
N
220
0
p
p
R
0
R
0
R
0
(1x10 -l
T
3
p
17
0
0
R
0
X
X
c
X
X
-
-
-
-
p
3
c
c
c
E
E
E
s
s
s
s
s
s
+
s
s
E
E
E
+
E
D
D
D
_,_
D
Atyp
E
CXl
w
AUGUST 8th
A
SPC(bact/m1)
Presumptive
90
B
c
N
N
0
0
T
T
0
p
Confirmed
EMB
X
X
SPC Standard
-
Confirmed
Standard
-
D
E
F
G
1200
310
340
300
5
0
0
0
0
0
0
0
5
X
X
X
X
X
X
X
X
X
X
X
X
X
X
H
R
R
0
-
J
K
I
llO
(1x1o- 1 <1x1o- 1 (1x10 - 1 '
I
p
0
I
c
c
E
E
s
s
s
s
+
+
+
+
-
-
-
-
E
E
D
+
-
-
-
-
-
-
-
N
N
0
0
1800
3
2
(1x10- 1
T
T
3
0
0
0
p
0
p
0
3
X
X
X
X
X
X
X
X
X
X
D
Atyp
AUGUST 9th
SPC (bact/m1)
<1x10- 1
Presumptive
0
N
0
440
T
0
p
Confirmed
X
R
X
0
EMB
X
SPC Standard
-
Confirmed
Standard
-
c
X
E
s
s
E
D
+
-
R
R
0
0
(1x1o- 1 <1x10- 1
c
c
E
E
s
s
s
s
+
-
-
-
-
-
E
E
+
-
-
D
-
-
D
-
Atyp
co
~
AUGUST lOth
A
SPC (bact/ml)
1
B
c
50
N
0
D
(lxlO-l
T
Presumptive
0
0
X
X
0
R
X
X
SPC Standard
-
-
Confirmed
Standard
-
-
(lxlO-l
3
c
X
E
D
7
H
--
190
I-
J
K
--
24
N
0
1
T
0
0
3
0
0
R
p
X
X
3
X
X
-
c
X
R
0
E
s
s
450
G
p
0
EMB
F
-
T
p
Confirmed
E
N
0
0
X
X
Atyp
c
X
E
X
E
+
-
-
-
-
-
+
-
18
55
13
7
2
2
0
5
0
0
0
1
X
5
X
X
X
Typ
X
Typ
X
X
X
s
s
+
-
-
-
-
-
E
+
-
+
-
-
-
s
s
E
D
-
s
s
-
E
D
AUGUST 11th
SPC(bact/ml)
Presumptive
0
0
N
0
T
N
8
0
p
Confirmed
X
X
R
X
X
SPC Standard
-
-
Confirmed
Standard
-
-
c
X
E
D
)3000
R
0
X
E
s
s
T
p
0
EMB
0
-
c
E
D
-
--·-
-
00
U1
AUGUST 12th
A
SPC (bact/m1)
Presumptive
(1x10- 1
B
N
0
c
D
N
0
19
T
T
p
p
0
E
<1x10 -
F
1
510
H
G
N
0
4
T
0
0
I
N
0
J
450
K
1<1x10-J
T
0
0
p
0
0
p
Confirmed
X
R
0
R
0
X
X
X
X
X
EMB
X
c
R
0
X
c
R
0
X
X
X
c
X
c
X
X
E
E
s
s
s
s
+
-
E
D
E
D
-
-
SPC Standard
-
Confirmed
Standard
-
E
-
-
+
-
-
-
-
s
s
E
s
s
-
E
D
12
34
.5
17
1
E
D
-
-
AUGUST 13th
SPC (bact/m1)
N
0
>3000
T
Presumptive
> 3000
EMB
0
X
5
c
X
5
Type
E
s
s
Confirmed
Standard
E
D
460
l
0
0
0
0
0
0
R
0
0
X
X
X
X
X
X
c
X
X
X
X
X
X
X
-
+
-
-
-
-
-
-
-
-
-
-
-
-
p
R
0
SPC Standard
60
T
p
Confirmed
N
0
E
+
+
-
s
s
+
E
D
------
00
0'\
AUGUST 14th
A
SPC (bact/m1)
13
Presumptive
0
B
N
0
c
240
D
F
E
15
60
1
0
G
H
I
J
890
3
N
0
6
14
0
0
0
0
0
X
X
X
X
X
X
-
-
-
-
-
-
N
0
N
0
10
T
T
p
p
R
0
T
X
R
X
SPC Standard
-
Confirmed
Standard
-
c
X
0
X
X
X
E
1
R
0
X
X
X
X
X
E
s
s
-1
p
0
EMB
'
( 1x10
T
0
p
Confirmed
K
+
-
-
+
-
-
-
-
-
-
D
-~---~
--
c
E
s
s
E
I
D
--
AUGUST 15th
SPC (bact/m1)
2
270
Presumptive
0
1
N
0
380
8
/'3000
150
0
0
3
0
T
p
Confirmed
X
EMB
X
1
Atyp
R
0
X
X
3
X
c
X
X
Atyp
X
E
SPC Standard
-
+
Confirmed
Standard
-
s
s
+
E
D
+
-
+
-
-
-
+
L - - - - - ---
(.1x10-l
0
0
R
0
X
X
X
X
-
-
c
c
E
E
s
s
s
s
E
E
D
D
-
co
-.....)
AUGUST 16th
A
B
c
SPC (bact/m1)
<1x10- 1
140
650
Presumptive
0
0
2
D
N
0
E
30
F
G
H
I
J
K
llO
5
130
)3000
5
(1xl0
-11
I
T
0
0
0
0
0
0
0
i
I
I
p
Confirmed
X
X
EMB
X
X
2
Atyp
R
0
X
X
X
X
X
X
X
c
X
X
X
X
X
X
X
-
-
-
-
+
-
-
-
-
-
-
-
-
E
SPC Standard
-
-
+
Confirmed
Standard
-
-
s
s
+
E
D
----·--
I
I
-
AUGUST 17th
SPC (bact/m1)
N
0
52
1800
T
Presumptive
EMB
1
170
270
800
1200
T
0
0
R
0
X
X
c
X
X
p
Confirmed
N
0
0
2
0
5
0
s
s
-
+
X
0
X
5
X
c
X
X
X
Atyp
X
Confirmed
Standard
E
D
-
-
s
s
E
D
0
p
R
0
E
SPC Standard
~
-<1x1o-
T
p
E
N
0
R
0
X
c
X
E
-
-
+
+
+
-
-
-
+
---
s
s
E
D
-
1
1
I
I
i
I
-
00
00
AUGUST 18th
A
B
c
D
E
F
SPC (bact/m1)
28
47
9
190
9
<1x10- 1
Presumptive
0
0
0
0
0
0
Confirmed
X
X
X
X
X
EMB
X
X
X
X
SPC Standard
-
-
-
Confirmed
Standard
-
-
-
H
I
J
K
380
llO
5
1
0
0
0
0
0
X
X
X
X
X
X
X
X
X
X
X
X
X
-
-
-
-
+
-
-
-
-
-
-
-
-
-
-
-
G
31
-----
AUGUST 19th
SPC (bact/m1)
105
630
800
88
10
29
N
0
)3000
T
Presumptive
0
0
0
0
0
0
X
X
X
X
X
X
EMB
X
X
X
X
X
X
SPC Standard
-
+
+
-
-
-
Confirmed
Standard
-
-
-
-
-
-
N
0
T
T
p
p
R
0
R
0
X
X
2
p
Confirmed
N
0
R
0
2
c
Atyp
E
0
c
c
E
E
s
s
+
s
s
s
s
E
+
E
E
D
D
D
3
-
00
0.0
AUGUST 21st
SPC (bact/ml)
A
N
B
0
8
c
D
E
F
3000
67
29
2
0
450
T
Presumptive
R
5
c
0
0
I
JN
K
560
14
0
l<r.x10-I
X
5
0
X
X
R
0
X
Atyp
X
X
X
c
1
X
s
s
-
+
-
-
+
Confirmed
Standard
E
D
-
+
-
-
-
N
N
N
SPC (bact/m1)
4
43
0
0
0
T
T
T
Presumptive
0
1
R
X
0
Atyp
X
E
SPC Standard
0
p
0
E
i
T
1
p
0
EMB
H
T
0
p
Confirmed
G
N
c
X
i
E
s
s
+
-
E
D
+
-
N
N
0
0
T
T
-
s
s
-
E
D
AUGUST 22nd
Confirmed
EMB
X
X
0
X
SPC Standard
-
-
Confirmed
Standard
-
-
p
p
p
R
R
R
0
0
0
c
c
c
E
E
E
s
s
s
s
s
s
E
D
E
E
D
D
2000
120
0
0
X
X
p
X
X
+
-
-
-
5
(lx1o- 1:
0
0
X
X
X
X
-
-
'
p
R
R
0
0
c
c
E
E
s
s
s
s
E
E
D
D
-~
\.0
0
AUGUST 23rd
A
SPC (bact/m1)
22
Presumptive
0
B
280
c
1300
D
N
0
E
F
~
G
570
480
230
5
0
0
H
27
T
0
0
X
X
X
EMB
X
X
X
SPC Standard
-
+
+
Confirmed
Standard
-
-
-
4
X
X
X
Typ
X
X
X
s
s
+
+
+
-
E
D
+
-
-
-
R
0
c
J
K
N
0
~x10- 1
T
T
p
p
R
R
0
0
c
c
E
E
s
s
s
s
E
E
D
0
p
Confirmed
IN
0
E
0
D
I
X
I
X
-
-~
AUGUST 24th
SPC (bact/m1)
1400
N
0
33
460
36
450
390
34
22
26
IG.x1o-
1
T
Presumptive
0
0
0
0
1
0
0
0
0
0
R
0
X
X
X
0
X
X
X
X
X
c
X
X
X
X
X
X
X
X
X
-
+
-
+
+
-
-
-
-
-
-
-
-
-
-
-
-
-
p
Confirmed
X
EMB
X
E
SPC Standard
+
Confirmed
Standard
-
s
s
E
D
---
··--
1.0
I-'
AUGUST 26th
SPC (bact/ml)
A
N
0
B
99
c
67
T
Presumptive
EMB
0
0
R
0
X
X
c
X
X
s
s
Confirmed
Standard
E
D
28
F
G
)3000
N
0
H
N
0
I
N
0
T
T
T
0
0
R
0
X
X
c
X
X
p
E
SPC Standard
E
T
p
Confirmed
D
N
0
E
0
p
R
0
R
0
X
X
X
X
+
-
-
-
c
c
c
E
E
E
s
s
s
s
s
s
E
D
E
E
D
D
130
900
N
0
-
-
N
0
N
0
N
0
N
0
T
T
T
T
p
p
p
p
R
R
0
R
0
R
0
X
X
-
'
0
p
E
D
-
s
s
2300 KlxlO-l
R
0
+
-
K
p
-
-
J
j
AUGUST 27th
SPC (bact/ml)
Presumptive
Confirmed
51
0
X
11
0
X
0
0
E.MB
SPC Standard
Confirmed
Standard
X
-
X
-
c
c
c
c
E
E
E
E
s
s
s
s
s
s
s
s
E
E
D
E
D
E
D
D
5
<lxlO-l
0
0
R
0
X
X
c
X
X
-
-
-
-
T
2
p
2
Atyp
E
-
+
-
s
s
+
E
D
-
-~
1.0
I\.)
AUGUST 28th
SPC (bact/m1)
A
N
B
c
0
250
D
E
F
G
260
15
99
12
33
0
0
0
0
0
X
X
X
X
X
X
X
+
+
-
-
-
140
42
12
470
H
I
J
K
2600
8
10
1
0
4
0
0
0
X
X
4
X
X
X
X
X
X
Typ
X
X
X
-
-
-
+
-
-
-
-
-
+
-
16
220
)3000
4
13
•~1x10- 1
T
Presumptive
p
Confirmed
R
0
EMB
c
E
SPC Standard
s
s
Confirmed
Standard
E
D
-
I
-__ I
AUGUST 29th
SPC (bact/m1)
30
Presumptive
0
0
0
0
0
0
0
1
0
0
0
Confirmed
X
X
X
X
X
X
X
1
X
X
X
EMB
X
X
X
X
X
X
X
Atyp
X
X
X
SPC Standard
-
-
-
-
+
-
+
+
-
-
-
-
-
-
-
-
-
+
-
-
Confirmed
Standard
"-
-
1.0
w
AUGUST 30th
A
SPC (bact/ml)
Presumptive
160
0
B
2800
c
D
120
450
E
61
F
250
G
59
H-
I
">3000
140
J
N
0
K
--
(lxlO-l
T
0
1
2
0
3
2
1
0
0
p
Confirmed
X
X
0
EMB
X
X
X
2
Type
X
0
0
X
X
X
SPC Standard
-
+
-
+
Confirmed
Standard
-
-
-
+
-
N
0
480
400
25
1
Atyp
X
X
+
-
+
-
-
-
+
N
0
128
N
0
R
0
c
X
X
E
-
-
s
s
E
D
-
41
17
0
0
0
R
0
X
X
X
c
X
X
X
-
-
-
-
-
AUGUST 31st
SPC (bact/ml)
31
T
Presumptive
T
0
0
0
0
p
R
0
X
X
X
X
EMB
c
X
X
X
X
E
SPC Standard
s
s
Confirmed
Standard
E
D
0
p
Confirmed
+
-
+
-
-
-
-
p
R
0
X
c
X
E
s
s
E
D
l<lxlO-l
T
-
E
s
s
E
D
1..0
~
SEPTEMBER 1st
SPC (bact/m1)
A
N
B
N
c
0
0
65
5
12
T
T
0
0
0
Presumptive
Confirmed
EMB
SPC Standard
Confirmed
Standard
p
p
R
R
0
0
c
c
E
E
s
s
s
s
E
E
D
D
SPC (bact/m1)
14
44
Presurnpti ve
0
0
X
X
D
X
X
E
-
X
X
-
-
-
-
-
-
F
N
G
H-
N
N
I
N
J
N
0
0
0
0
0
T
T
T
T
T
p
p
p
p
p
R
R
R
R
R
0
0
0
0
0
K
--
(1x10- 1
0
c
c
c
c
c
E
E
E
E
s
s
E
s
s
s
s
s
s
s
s
X
X
-
E
E
E
E
D
D
D
D
- Q__L._
51
520 k1x10-
E
SEPTEMBER 2nd
N
0
N
230
22
T
X
X
R
0
X
X
X
X
SPC Standard
-
-
Confirmed
Standard
-
-
c
s
s
E
D
R
X
X
+
-
-
-
c
E
s
s
E
D
2'
T
0
0
0
X
X
X
X
X
X
-
+
-
p
X
0
E
0
0
p
0
EMB
N
88
T
0
p
Confirmed
0
R
0
X
c
-
E
-
E
s
s
D
i
-
-
-
----------
1.0
U1
SEPTEMBER 3rd
A
SPC (bact/ml)
Presumptive
Confirmed
EMB
5
B
N
0
c
D
N
0
10
T
T
p
p
0
X
X
SPC Standard
-
Confirmed
Standard
-
R
R
0
c
c
E
E
s
s
s
s
650
F
N
0
G
8
T
0
0
E
5
5
0
R
Typ
c
X
+
-
+
s
s
K
3000
130
klxlO -2'
3
0
0
2
X
X
Atyp
X
X
-
-
R
X
-
-
c
E
s
s
+
E
+
E
E
D
D
N
0
N
0
N
0
N
0
N
0
N
0
N
0
N
0
T
T
T
T
T
T
T
T
p
p
p
p
p
p
p
p
R
R
R
c
0
0
c
c
R
0
R
0
c
R
0
4
0
R
0
R
0
c
c
c
c
Atyp
E
E
E
s
s
E
s
s
E
s
s
E
E
s
s
s
s
E
s
s
s
s
s
s
+
E
E
D
E
E
E
E
E
E
+
D
D
D
D
D
D
E
!
0
E
-
J
p
0
X
I
T
p
X
H
N
0
D
I
'
I'
D
SEPTEMBER 4th
SPC (bactjml)
130
Presumptive
0
Confirmed
EMB
SPC Standard
Confirmed
Standard
X
X
-
D
1200 l<1x104
2
0
I
X
I
X
I
I
I
I
--
\.0
0"1
97
APPENDIX 3
Bacteriological Study:
Accumulated Results
Pool
# of times
sampled
# of times
exceeding
200 bact/ml
(SPC)
# of times
exceeding
0 tubes
confirmed
A
21
1
1
B
20
8
2
c
20
11
5
D
20
6
2
E
21
5
3
F
22
16
4
G
24
6
1
H
21
11
11
I
20
4
2
J
23
5
1