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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. 3 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 7 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 10 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 REFERENCES CITED Amies, C. R. (1956} "Surface Film on Swimming Pools," Canadian Journal of Public Health, 47:93-103. Baginsky. (1896} Uber die Bassinbaeder Berlins. Gottingen, Germany: Hygienische Rundschau, Vol. 6, pp. 597620. cited by Luehring, F. W. (1939}. Swimming Pool Standards New York. A.S. Barnes and Co. 273 pp. Bahn, C. A. (1927} "Swimming Bath Conjunctivitis," New Orleans Medical and Surgical Journal, 79:586-58~ Balacescu, C., Grun L. (May 1975}, "Bacteriological and Parasitological Investigations in Public Indoor Swimming Baths," Zentralbl Bakteriol 160(3) :292-6. Beaufield, R.M. (1919) "Reinforced Concrete Swimming Tank, Ft. Bliss, Texas," Engineering News. 82:195-196. Bell, John. (1850} A Treatise on Baths. Barrinton and Haswell, 658 pp. Philadelphia: Bell, J. A., Muebner, R. J., Rowe, W. P., Engler, J. I. and Parrot, R. H. (1955} "Pharyngo Conjunctival Fever," Journal of the American Medical Association. 157:1083-1092. Bliss, C. E. (1918} "Large Outdoor Swimming Pool, Built in Circular Form," Engineering News. 80:997. Bliss, A. H. and Steinmetz, W. H. (1958} "Health Service Responsibilities for College and University Swimming Pool Operation," Sanitarian ~1:14-18. Brown, J. R. (1964} "The Public Health Hazards of Bathing," Medical Services Journal of Canada, 20:135. Bundesen, H. N. (1934} Journal of the American Medical Association, 102:367. Bunker, J. W• .f\1. (1910} "The Hygiene of the Swimming Pool," American Journal of Public Hygiene. 20:810-812. Burrage, S. (1911} "Hypochlorite as a Means of Disinfection of Swimming Pools," Engineering News Records, 63:740. Caldwell, G. G., Lindsey, N. J., Wolff, J., Donnelly, D.D. and Bohl, F.N. (1974} "Epidemic of Adenovirus Type 3 Acute Conjunctivitis In Swimmers," American Journal 70 of Epidemiology, 99(3) :230-4. California Administrative Code, Chapter 5, Subchapter 1, Group b, Sections 7774 - 7833 Title 17, Public Health from Laws and Regulations Relating to Swimming Pools (1974) State of California Department of Health. California Health and Safety Code, Division 20, Chapter 1, Sections 24100-24109 from Laws and Regulations Relating to Swimming Pools (1974) State of California Department of Health. Carter, R. F. (1970). "Description of isolated from two cases of primary cephalitis and of the experimental changes induced by it." Journal of a Naegleria sp. amoebic meningoenpathological Pathology, 100:217. Cerva, L. and Novak, K., (1968). "Amoebic meningo-encephalitis: Sixteen fatalities." Science, 160-92. Chang, S.L. (1971). "Small free-living amoebas: cultivation quantitation, identification, classification, pathogenisis and resistance." Current Tonics Comparative Pathology, Vol. 1, Academic Press Inc., New York and London, pp. 201-254. Chanlett, E. T. and Gotaas, H. B. (1942). "The Time Factor in the Chlorine and Chloramine Disinfection of Contaminated Swimming Pool Water," American Journal of Public Health, 32:355-364. Clarke, rJ.A., and Chang, S.L. (1959). Journal of American Water Works Association, 51:1299. Cleveland, D. E. H. (1951). "Possible Tuberculosis Skin Infection from a Swimming Pools," Acta dermato-venercologica, 31:147-152. Cockburn, A. T. (1953). "Epidemic of Conjunctivitis in Colorado," American Journal of Opthamology, 36:15341539. Committee on Bathing Beach Contamination of the Public Health Laboratory Service (1959). Journal of Hygiene (Carob.) 57-435. Committee on Bathing Places, (1922). "Third Report of Committee on Bathing Places," American Journal of Public Health, 12:2:121. Committee on Public Bathing Places, (1926). Report APHA. 71 Constant, E. H. (1908). "A Swirruning Pool for the University of Minnesota," Engineering News, 60:737. Crone, P. B. and Tee, G. H. (1974). "Staphylococci in Swirruning Pool Water," Journal of Hygiene, Cambridge, 73:213. Department of Health, California State, (1974). Regulations Relating to Swimming Pools. Laws and Derrick, E. H. (1943). "Swirruning Bath Conjunctivitis; With A Report of Three Probable Cases and A Note on Its Epidemiology," Australian Medical Journal, 2: 334-337. DeSilver, Robert (1829). DeSilver's Philadelphia Directory and Strangers Guide. Philadelphia: Robert DeSilver, 230 pp. Cited by Luehring, F. W. (1939). Swirruning Pool Standards New York. A. S. Barnes and Co. 273 pp. Duke, E. (1932). 2, p. 1586. Textbook of Opthamology, McGraw-Hill, Vol. Ehlers, V. M. and Steel, E. W. (1965). Municipal and Rural Sanitation, sixth edition, McGraw Hill, San Francisco. Pp. 663. Even-Paz, z., Haas, H., Sacks, T., Rosenmann, E., (1976). "Mycobacterium marinum skin infections mimicking cutaneous leishmaniasis," British Journal of Dermatology, 94:435. Fair, G. M. (1920). "An Inferential Index of Swirruning Pool Purity," American Journal of Public Health. 10:502-508. Farnham, G. S. (1910). "The Carnegie Swirruning Pool at Yale University," Engineering News 64:144. Faust, E. C., Russel, P. F., Jung, R. C. (1970). Craig and Faust's Clinical Parisitology, 8th edition, Lea & Febiger, Philadelphia. Pp. 890. Favero, M. S., Drake, C. H., and Randall, G. B. (1964). "Use of staphylococci as indicators of swirruning pool pollution," Public Health Reports, Washington, 79:61. Fehr, (1900). Endemische Bad-Konjunktivitis, Berlin Kl. w. Nr. l. Cited by Bahn, C.A. (1927) "Swirruning Bath Conjunctivitis," New Orleans Medical and Surgical Journal 79:586-88. . 72 Ferramola, R., Elena Durieux, J. (1951). "Bacterias coliformes y coco Gram positives en aquas de natatorios," Revista de Orbas Sanitariasde la Nacion, 15:173. English abstract in Bulletin of Hygiene (1952) 27:179. Fletcher, A. H. and Link, E.C. (1933). "Some factors involved in the Use of Chloramines for the Disinfection of Swimming Pools," American Journal of Public Health, 2 3: 1255-1261. Fletcher, A. H. and Clark, A.E. (1933). "Application of the Principles of Water Purification to the Control of Swimming Pools," American Journal of Public Health, 23:407-425. Fowler, M., and Carter, R. F., (1965). Acute pyogenic meningitis probably due to Ancanthamoeba ~-= a preliminary report," British Medical Journal, 2:240. Foy, H. M., Cooney, M.K., Hatlen, J. B. (1968). "Adenovirus Type 3 Epidemic Associated with Intermittent Chlorination of a Swimming Pool," Archives of Environmental Health, 17:795. France, R. L., and Fuller, J. E. (1940). "Colif6rm bacteria and streptococci in swimming pool water." American Journal of Public Health, 30:1059-1062. Gallagher, J. R. (1948). "Swimming Pools, Their Relationship to Illness," New England Journal of Medicine, 238-899-901. Girard, P. S. (1832). "Recherches sur Les Etablissements de Bains Publics a Paris, Depuis IV Siecle Jusqua Present." Ann ales d 'Hygiene Publique et De Medecine Legal Tome Septieme, Primiere Partie, Paris, 1852: 5:59. Cited by Luehring, F. W. (1939). Swimming Pool Standards (New York. A.S. Barnes and Co. 273 pp. Gradle (1916). 12:653. "Swimmers Conjunctivitis," QE_thalmology, Hartwell, Edward Mussey (1897). Public Baths in Europe. United States Bureau of Labor, Bulletin 2:434-86. Cited by Luehring, F.W. (1939). Swimming Pool Standards New York. A. S. Barnes and Co. 273 pp. Heinz, F., Bindas, B., Cervenka, P. Zdesska E. (Nov. 1977). "Epidemics of Swimming Pool Conjunctivitis Caused by Adenovirus Type 3," Cesk Epidemiol. Mikrobiol. Immunol. 25 (6): 321-5. 73 Hellerstrom, s. (1952). "Water-borne tuberculosis and similar infections of the skin in swimming pools." Acta dermato-venereologica, 33:449. Herlitz, S. (1953). "Cutaneous infection contracted in a swimming pool and resembling tuberculosis," Acta dermato-venereologica, 33:156. ---Hicks, J.H. (1977). 19:4:448-50. "Swimming and the Skin," Cutis Horwood, M.P., Gould, B.S., and Shwachman, H. (1933). "Indices of the sanitary quality of swimming pool waters," Journal of the American Water Works Association, 25: 125-34 ~ Humphrey, H. (1978). "Public Swimming Pool Water Disinfection: A Review of the Current Situation," Royal Society of Health Journal, 98:1:22~4. Interviews: Satashi Miyata, L.A. County Senior Sanitarian, July 1978 and January 1979. Jacobson, J.A., Hoadley, A.W., and Farmer, J.J. (Nov. 1976) "Pseudomonas aeruginosa: Serogroup II and Pool Associated Skin Rash," American Journal of Public Health, 66(11): 1092-3. Kadlec, V., Cerva, L., Skvarova, J. (1978). "Virulent Naeglaria fowleri in an Indoor Swimming Pool," Science, 201(4360):1025. Keirn, M.A. and Putnam, H.D., (1968). "Resistance of Staphylococci to halogens as related to a swimming pool environment," Health Laboratory Science, 5:180. Klassen, C.W., (June, 1953). "Sanitation Sells Swimming," Modern Sanitation, 5:24-24. Kozlowska, D. and Wichrowska, B. (1976). "The effect of chlorine and its compounds used for disinfection of water on Trichomonas vaginalis," Wiad Parazytol, 22 (4-5): 433-5. Kraus, H. and Tiefenbrunner, F. (May 1975). "Randomized Investigations of Some Tyrolean Swimming Pools for the Presence of Trichomonas vaginalis and Pathogenic Fungi," Zentralbl Bacterial, 160 (3): 286-91. Kroeber, F.V. (1976). Public Swimming Pools. South Brunswich and New York: A. S. Barnes and Co. 74 Levine, M., (1916), "The Sanitary Control of Swimming Pools," Journal of Infectious Diseases, 18:293. Lewis, W. L. (1911). "Hypochlorite Disinfection of an Indoor Swimming Tank at Northwestern University," Engineering News, 65:689-690. Linell, F. and Norden, A. (1954). "~cobacterium balnei: a new acid-fast bacillus occurring in swimming pools and capable of producing skin lesions in humans," Acta tuberculosea et Pneumologica Scandinavica, Supplement~3. Ling, W. P. (1936). "Keratosis Punctata Superficialis, and Swimming Pool Conjunctivitis," Chinese Medical Journal of Public Health, 45:100. Little, G. M. (1954). "Poliomyelitis and Water Supply," Canadian Journal of Public Health, 45:100. Luehring, Fredrick W. (1939). Swimming Pool Standards. New York. A. S. Barnes and Co. 273 pp. Mallmann, W. L. (1928). "Streptococcus as an indicator of swimming pool pollution," American Journal of Public Health, 18:771-776. Mallmann, W. L. and Cary, W. (1933). "Study of bacteriological Methods of Testing, and Means of Disinfecting Water with Chlorine," American Journal of Public Health, 23:35-44. Mallmann, w. L. (1935). "Bacteria,l QualityofSwimming Pool Waters," Annual Report, Division of Veterinary Science, Michigan State College, East Lansing, 1935, pp. 59-65. Cited by France, R.L., and Fuller, J .E., (1940). "Coliform bacteria and streptococci in swimming pool wate4" American Journal of Public Health, 30:1059-62. Mallmann, W. L. (1962). "Cocci test for detecting mouth and nose pollution of swimming pool water," American Journal of Public Health, 52:2001-2008. Mannhiemer, W.A. (1914). "Studies on the Sanitation of SwimmingPools,"American Journal of Infectious Diseases, 1:158-169. Mannhiemer, W. A. (1917). "Comparison of Methods for Disinfecting Swimming Pools," Journal of Infectious Diseases, 20:1-9~ Marshall, Sir John (1931). Mohenjo-Daro and the Indus Civilization, VoL I. London: Probsthein, xxvii, 364 pp. 75 Cited by Luehring, F.W. (1936). Swimming Pool Standards New York. A.S. Barnes and Co., 273 pp. McCausland, w. J., Cox, P. J. (1975). "Pseudomonas infection traced to motel whirlpool," Journal of Environmental Health, 37:455-459. Mehl, Erwin (1927). Atike Schwimmkubst, Munchen, Germany: Ernst Heimeran, 142pp. CitedbyLuehring, F.W. (1939). Swimming Pool Standards New York. A. S. Barnes & Co. 2 73 pp. Miller, J.E., Mallmann, W.L., Devereux, E.D., {1942). "Stabilization of Chlorine in Water," American Journal of Public Health, 32:1025-28. Ministry of Health, (1929). The Purification of the Water of Swimming Baths. London: His Majesty's Stationary Office. 52 pp. Mood, E. W. {19 50) • "Effect of Free and Combined Available Residual Chlorination in the Treatment of Swimming Pool Waters," American Journal of Public Health, 40:459-466. Mood, E.W. {1953). "Development and Application of High-Free Residual Chlorination in the Treatment df Swimming Pool Water," American Journal of Public Health, 43:1258-64. Ormsby, H. L., Fowle, A. M. C., and Cockerman {1955). "!>. Relationship of Epidemic Keratoconjunctivitis to the Adenoidal Pharyngeal, Conjunctival Virus Syndrome," Canadian Medical Association Journal, 73:710-849. Ormsby, H. L., and Aitchison ( 19 55) • "The Role of the Swimming Pool in the Transmission of pharyngeal-conjunctival fever," Canadian Medical Association Journal, 7 3: 864. Piekarski, G., Saathoff, M., Stuer, D. {1972). "Investigations on the Viability of Trichomonas vaginalis in Tap Water and Public Swimming Baths," Zentralbl Bakteriolgic, 157{2):202-14. Pospisilova, D. {1973). "Helmintalogicke Vysetreni Bazenu Mesta Brna," Cs. Epidemiologic, Mikrabiologic, Immunologic {English Abstract) 22{5):291-3. Report: Joint Committee on Bathing Places {1926). can Journal of Public Health, 16:1186-1201. Ameri- Report, {1953). "The choice of an indicator organism for the bacteriological control of swimming bath purification," Monthly Bulletin of the Ministry of Health and 76 the Public Health Laboratory Service, 12:254. Rhodes, A. J., et al (1950). Health, 41:146. Canadian Journal of Public Robinton, E. D., Mood, E. W., Elliot, L. R., (1957). "A Study of Bacterial Flora in Swimming Pool Water Treated with High-Free Residual Chlorine," American Journal of Public Health, 47:1101. Robinton, E. D. and Mood, E. W. (1966). "A quantitative and qualitative appraisal of microbial pollution of water by swimmers: a preliminary report," Journal of Hygiene,_ Cambridge, 64:489. Santler, V. R., and Thurner, J. (1974). "Untersuchungen uber die Ansteckungsmoglichkeit durch Trichomonas vaginalis," Wiener Klinische Wochenschrift, English Abstract, 86(2):46-9. Sausker, W. F., Aeling, J. L., Fitzpatrick, J. E. and Judson, F. N. (1978). "Pseudomonas Folliculitis," Journal of the American :Medical Association, 239 (22) :2362-5. Scharf, of L. F. A. J. Thomas and Westcott, Thompson (1884). History Philadelphia, 1601-1884, Vol. I. Philadelphia: H. Everts & Company, 852 pp. Cited by Luehring, W. (1939). Swimming Pool Standards New York. S. Barnes and Co. 273 pp. Schleyer, W. (1909). Bader and Badeanstatten. Leipzig: Carl Scholtze (W. Junghans), xvi, 748 pp. Cited by Luehring, F. W. (1939). Swimming Pool Standards New York. A. s. Barnes and Co. 273 pp. Singh, B. N., and Das, S. R. (1970). "Studies on pathogenic and non-pathogenic small free-living amoebae and the bearing of nuclear division on the classification of the Order Amoebida." Philadelphia Transactions of the Royal Society of London, 259:435. Skutch, R. (1892). "Uber Vulvovaginitis Gonorrhoica Bea Kleinen Hadchen," Zentral Bakteriol-Parisitol, 12:309310. Cited by Holdstock, R. s. (1959), "The effect of Swimming Pool Skimmers on Bacterial Densities in the Surface Film of Swimming Pools." Unpublished M.• S. thesis, UCLA. Standard Methods for the Examination of Water and Wastewater, 14th edition (1975) . APHA. 77 Stokes, W. R. and Thomas, J. B. (1905). "The Effect of Copper Sulfate Upon the Bacteriological and Chemical Constituents of Large Bodies of Water," Journal of American Medical Association, 10:1075. Stovall, ~.v. D. and Nichols, s. M. (1917). "Some Factors in Swimming Pool Control," Journal of Infectious Diseases, 21:484-492. Stovall, W. D. and Nichols, S. M. (1923). "Chlorination of Swimming Pool Water," American Journal of Public Health, 13:478-480. Stovall, W. D., Nichols, S. M. and Vincent, V. E. (1926). "Renovation in Swimming Pool Control," American Journal of Public Health, 16:237-243. Taylor, H. M. (1923). "The Causes and Prevention of Otologic Conditions Following Swirmning and Diving," Journal of the American Medical Association, 81:349-351. Thompson, A. W. S. (1950). "Poliomyelitis in Auckland, 1947-1949. An Epidemiological Study," Journal of Hygiene (Cambridge), 48:96-120. Thygeson, P. and Stone, W. (1942). "Epidemiology of Inclusion Conjunctivitis," Archives of Opthamology, 27:91-119. Tully, E. J. (1912). "The Hygiene of the S'l.vimming Pool," American Journal of Public Health, 2:186-193. Van der Veen, J. and Van der Ploeg (1958). "Pharyngoconjunctival Fever Caused by Adenovirus Contacted in Swimming Pools," American Journal of Hygiene, 68:95. Victorin, K. (1974). "A field study of some swimming pool waters with regard to bacteria, available chlorine and redox potential," Journal of Hygiene, (Cambridge) 72:101. Villa, L. and Zaffino, L. (1970). "Studio comparative degli indici batterici di inquinamento delle acque de piscina." Annali dell Institute Superiore di Sanita, 6:1. English abstract in Abstracts of Hygiene (1971), 46:530. Viterbro, L. R. (1919). "Swimming Tank of Third Floor of Concrete Building," Engineering News, 83:135-136. ,, 78 Walker, W. F. (1922). "The Treatment of Swimming Pool Water with Ultraviolet Rays," American Journal of Public Health, 12:320-324. Washburn, J., Jacobson, J. A., Marston, E., Thorsen, B., (1976). "Pseudomonas aeruginosa Rash Associated lvith a Whirlpool," Journal of the American Medical Association, 235(20):2205-7. Whipple (1911). "Notes and Answers," Engineer, 30:577. ~1unicipal Journal and Wickman, 0. I. (1907). "Beitrage Zur Kenutnis der HeineMedinschen Krankheit (Poliomyelite acute and verwandker Erkrankungen." Berlin, S. Karger. Cited by Brown, J. R.- (1964) • "The Public Health Hazards of Bathing," Medical Services Journal Canada, 20:135. Winslow, C. E. A. (1923). The Evolution and the Significance of the Modern Public Health Campaign,_ New Haven, Yale University Press. Wolff, Carl (1908). Offentliche Bade und Schimmstalten. Leipzig: J. G. Goschensche Verlagshardlung, 151 pp. 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