CTI Presentation Script

Transcription

1 CTI Presentation Script 1 Today I am going to discuss the proposed New York Legionella Regulations. The pending regulations were created in response to a very large outbreak of Legionnaires Disease in New York City s South Bronx area last summer, and have the potential to set a precedence throughout the country. 2 So, the question posed by this presentation is Are the New York Legionella Regulations missing the boat? And the simple answer is Yes!! 3 This presentation will explain that the proposed New York Regulations are based completely on an Investigation Bias that immediately concluded a cooling tower MUST be the cause, without testing any other possible sources. It will show that, by using Epidemiology 101, the scientific community has come to a consensus that the PRIMARY source of Legionella infections is potable water. This presentation will also discuss why it is easy to conclude that the recent New York regulations will be ineffective at preventing Legionnaire s Disease, And, it will provide a solution for using proper problem solving techniques, such as ASHRAE Standard 188 and Guideline 12, to effectively mitigate Legionnaire s Disease.

2 4 5 First, a little background. By the end of the August 2015 outbreak of Legionnaires disease in New York City, 133 people had become sick (shown by the red circles) and 16 had died. This was the first of 3 sequential outbreaks in the Bronx. We will talk about the initial South Bronx outbreak first. According to the New York City Department of Health, the source was identified as a Cooling Tower at the Opera House Hotel. As a side note, it should be pointed out that the Opera House Hotel cooling tower is a new unit with high efficiency drift eliminators, which means it has a very low drift rate and makes it unlikely to be the true source. But more on that later 6 The outbreak caused widespread panic which resulted in a knee jerk response by the Health Department on August 6 th for inspection and disinfection of all cooling towers in New York City. This was followed by a swiftly passed law passed on August 18 th. This law is also focused entirely on Cooling Towers and requires: registration, annual inspections and disinfection, additional maintenance, which was later detailed in November s proposed regulations, and compliance with a very small part of ASHRAE standard A quick response was also issued at the state level. This proposed emergency rule likewise focused on cooling towers and requires: Statewide registration of all cooling towers. Routine sampling of cooling towers with a requirement for non detection. Quarterly inspection and annual certification of all cooling towers, as well as public reporting of all sample results.

3 8 With their new regulations, New York is trying to reduce the occurrence of Legionnaire s Disease. Let s be clear, we all agree with this goal, but, by focusing only on cooling towers they are missing the boat on addressing the root cause of the problem and therefore the regulations will be ineffective. It is important for the state of New York to get this right. Other jurisdictions throughout the United States are monitoring these events and New York s regulations could become a bad and ineffective precedent that is replicated across the country. I am hopeful that this presentation and technical paper will help prevent this from happening. 9 So, why is there a focus on cooling towers? In 1976, there was an outbreak at an American Legion conference at the Bellevue Stratford Hotel in downtown Philadelphia where 221 people became ill and 34 died. This is the first known outbreak of the disease which was later named Legionnaires Disease in reference to the conference attendees. The investigation suspected that the source was a cooling tower but with better understanding of all potential sources it appears that not all contributing sources were recognized at the time. 10 At the time it was believed that the Legionella bacteria could only be colonized and delivered in the following way: First Legionellae bacteria, which are naturally occurring, are introduced into the potable water supply.

4 They then enter buildings via the piping system, and find hospitable growing conditions in only one piece of non drinking water equipment, such as a cooling tower. The bacteria proliferate in only that individual device and the bacteria are disseminated in aerosol form from only that single point source. The key concept in this exposure model is that all disease is a result of that single emission point. 11 Starting with the outbreak in Philly, and until the early 1980 s, this 4 step logic for bacteria growth and exposure was the only one used when investigating the source of infectious Legionella. It was believed the disease could be transmitted only by large equipment which emits aerosols. 12 Using this thought process cooling towers, spas, grocery misters, decorative fountains, and other aerosol sources were the only water systems investigated when an outbreak occurred. If Legionella was found in one of those sources, generally, no further investigation was pursued and often the root source was never discovered. Unfortunately, this antiquated logic was used by New York when investigating the recent outbreak in the Bronx. 13 Since the early 1980 s research has shown that many legionellosis outbreaks initially blamed on cooling towers, were actually caused by bacteria growth in the building s potable water and water systems, including building hot water heaters and poorly maintained plumbing. Outbreaks are frequently linked to delivery system disruptions. In fact, since about the year 2000 it has been known that the primary source of Legionnaires disease is potable water.

5 14 However, as we saw this past summer in the Bronx, the politically convenient Investigation Bias towards cooling towers and other aerosol point sources has yet to be eradicated from the public domain. By allowing this investigation bias to continue, investigators are actually excluding potential sources of bacteria from sampling and testing efforts, thus missing the upstream cause and allowing countless people to become sick. 15 To understand why the scientific community, including the CDC, WHO, EPA, VHA, and multiple research institutes no longer believe that Legionella is isolated to large equipment such as cooling towers, we must better understand the disease. Legionnaires disease is a severe form of pneumonia which is contracted by inhaling or aspirating water droplets containing Legionella deeply into the lungs by a susceptible host. 16 An unfortunately little known fact is that only 4% of all Legionellosis cases are classified as outbreaks. These outbreaks, which can be as small as two people or as large a last summer s occurrence, are the cases that get all of the public attention. In reality, fully 96% of reported Legionnaires disease cases are sporadic, meaning they are single cases. These cases get little public attention and are typically not investigated, but potable water from a variety of sources is suspected by the scientific community in most of these sporadic events. 17 I mentioned earlier that potable water as a source of Legionella was first recognized in the early 1980s. A hospital outbreak at the Pittsburgh Veterans Administration Medical Center led investigators to look beyond large equipment and to potable water systems within the building. Their sampling found the organism in showers, faucets, a bedpan flusher, and hot water storage tanks. This study as well as subsequent studies proved that potable water is a source

6 in Legionnaires' disease transmission, either via aspiration of Legionella from the mouth into the lungs or via inhalation of droplets emitted by sinks and showers. 18 The Pittsburgh Veterans Administration Medical Center outbreak is documented in an article published by the New England Journal of Medicine in 1982 where the investigation team looked at both cooling towers and alternate sources of the bacteria. It is important to note that by investigating alternate sources the hospital s epidemiology team was able to identify the root cause just as the disease began to spread throughout the hospital. In total, 20 people became ill but it could have been much worse had they prematurely stopped the investigation by blaming a cooling tower. 19 In this article, the researchers found a Legionella growth and exposure pattern quite different from the one that had been previously assumed. The researchers state, and I quote, On the basis of our study, we formulate the following scenario: Legionella pneumophila is introduced into the potable water supply (perhaps by seeding with low numbers of organisms from the supplying reservoir). The storage tanks and water system serve as a concentration mechanism whereby the organism proliferates in the hot water system. It is disseminated to patient areas through showers, faucets, and other water outlets The key point here being there are multiple origins of disease. 20 The article concludes with the very important statement: In institutional outbreaks of Legionnaires' disease, epidemiologic investigation has usually focused on nearby cooling towers and evaporative condensers. This study now indicates that attention should be directed to the water distribution system within the institution. I would like to highlight that this article was published in 1982.

7 21 This research and discovery has been confirmed and echoed again and again by various organizations throughout the scientific community, including the CDC. In reference to the source of Legionnaires disease Karlyn Beer of the CDC was recently quoted as saying What you hear about is the cooling towers, but the data show there s also risk with water from showers. and she said, "The key to preventing these outbreaks is maintenance of building plumbing systems. This sentiment is echoed in the August 2015 Morbidity and Mortality Weekly Report showing that 2/3 of all drinking water related outbreaks, of any kind, reported in were traced to Legionella. 22 The first article was published in years later, the CDC reiterates its conclusions, and yet public health authorities are still excluding public and building water supplies from root cause investigations. Why? 23 The quality of drinking water in the US is high, so how do we go from a low number of organisms in the water supply to doses that are high enough to cause infection or outbreak? As discussed in the 1982 New England Journal of Medicine article, all water pipes contain a layer of biofilm. This biofilm consists of many non pathogenic bacteria but can also harbor bacteria such as Legionella. Water main breaks cause pressure surges which can disturb biofilms in the pipes and release bacteria into the water stream, potentially causing disease. In 2014 alone there were 513 water main breaks in NYC. The American Water Works Association estimates there are 240,000 breaks per year in the US.

8 In addition, the water delivery systems, especially on the East Coast, are aging. Some systems go back to the 1800 s. As portions of those systems are replaced or enhanced, pressure surges can also occur. With both the population and the water systems aging we can t wait another 30 years for the Public Health Officials to get this right. 24 A very recent example of potable water system changes being linked to an outbreak of Legionnaires Disease occurred in Flint, Michigan. In this case high iron content caused by the corrosivity of the Flint River water may have been a contributing factor to the increase in Legionnaires disease cases. While most of the focus has been on the lead exposure, a recent article states: Although state officials say they can't pinpoint the source of the outbreak, Legionnaire's infections spiked sharply in Genesee County when Flint tried to save money by changing its water source from Lake Huron to the Flint River in April Two months later, there were six cases of Legionnaires' reported in Genesee County, and the number of cases remained elevated until Flint switched its water source back to Lake Huron in the fall of It is important to understand that while the scientific community was busy learning more about possible sources of Legionnaires disease, the cooling tower manufacturers were developing ways to reduce emissions from the cooling towers. While cooling towers are shipped clean and free of bacteria, manufacturers wanted to do everything possible to keep owners, operators and bystanders safe from any bacteria that could grow during unit operation. With that in mind, cooling tower manufacturers have made dramatic improvements in drift eliminator technology. For anyone who doesn t know, drift eliminators are the component of cooling towers that separates recirculating water from exiting air. Between 1995 and 2000 all major manufacturers of factory built cooling towers developed highly efficient cellular eliminators.

9 26 These modern drift eliminators, when installed properly and maintained, reduce aerosol emissions by an order of magnitude from the previous generation, helping to keep bacteria inside of the tower. 27 To demonstrate the effectiveness of modern drift eliminators, imagine that water in a cooling tower was contaminated with 1,000 CFU/ml of Legionella, which is a very high concentration. A person standing on top of the tower and breathing in only tower exhaust for 1 full hour would breathe in droplets containing a total of only 10 bacteria. Of course, people in the surrounding area will be exposed to an even lower concentration as the discharge air is dispersed. Note, the cooling tower at the Opera House Hotel, did in fact have the most current drift eliminators. Somehow, this information never made it to the news 28 We should also discuss the science of outbreak profiles. When discussing the epidemiology of Outbreaks there are two basic types that apply to the discussion today. Aerosol point source outbreaks are typically attributed to a single source such as a spa tub, fountain or cooling tower. Potable water outbreaks are typically attributed to shower heads, drinking water, ice machines, faucets, and building hot water tanks.

10 29 Let s start with Aerosol Point Sources, so that we may compare those profiles to the recent outbreak in the Bronx. As previously mentioned there have been many Legionnaires disease outbreaks traced to an aerosolized point source of the bacteria. In these cases Legionella bacteria have found hospitable growing conditions in a single device with aerosol emissions and have multiplied to become a point source of Legionnaires' disease. Investigation of these outbreak types typically reveals a dose response relationship between exposure and illness. A close relationship between time spent near the source and incidence of infection has been demonstrated in numerous carefully investigated studies. Following are a few examples of well studied outbreaks where, as one would expect, proximity to and time spent near the source, strongly affected the incidence of disease. 30 An outbreak of Legionnaires' disease at a 1999 flower show in the Netherlands was linked to a spa. As part of the investigation, exhibitors were tested for Legionella antibody levels and a close correlation was found between elevated antibodies and proximity of their booth to a particular spa display. 31 Here you see a map of the flower show exhibit hall. The infected spa was located at the W in Hall 3. The colors show the antibody levels of exhibitors at locations throughout the hall. The dark circles are confirmed exhibitor cases. The correlation of distance from the spa source to both the level of antibodies and to the incidence of disease is clear. This is a typical aerosol point source profile and it is intuitive.

11 The aerosol is diluted with increasing distance from the source. Reduced bacteria concentrations resulted in lower immune response in the exhibitors who were located farther away. 32 Here is a Legionnaires' disease outbreak case map from an aerosol sourced outbreak traced to a hospital cooling tower in Please note this case occurred prior to the development of modern drift eliminators!! Shaded areas of increasing size around the hospital were used for epidemiological investigation; black dots are individual cases. Investigators found a 20% decrease in infection risk for each 0.1 mile from the hospital. As one would expect there is a clear concentration of cases near the tower with a substantial reduction in cases further away. 33 So, with these past cases in mind, let s look at the New York City Department of Health official case map from the Bronx outbreak. All of the triangles are cooling towers. The red triangle near the bottom is the Opera House Hotel, and the black circle around it is 0.1 mile radius from the hotel. The green and red dots are reported cases of infection. The lack of spatial correlation between disease incidence and the purported source is an extremely strong indication that the specific cooling tower is not the source of the outbreak and that investigation of other sources should be pursued. 34 Also important to note remember this guys from a few slides back? With his nose directly over the cooling tower discharge he would only breathe 10 bacteria in one hour with a 1,000 CFU/ml concentration in the basin.

12 35 At the street level this exposure amount would reduce significantly so that at 0.1 mile from the hotel, the concentration of the tower discharge would be reduced by a factor of 117 to 1. In terms of exposure, this calculates out to a person standing in the same place, downwind from the tower, for 5 consecutive 24 hour days, to inhale all 10 of the bacteria discharged in the cooling tower discharge air from our previous example. 36 Looking again at the case map, red and green circles are cases, and the red triangle is the Opera House Hotel Cooling tower with a circle indicating a 0.1 mile radius. As you can see, very few of the cases are within 0.1 mile of the Opera House Hotel where you would expect to see a high incidence of the disease if, in fact, the Opera House Cooling Tower were truly the source. 37 But if the Bronx outbreak doesn t match the single aerosol point source profile as the New York City health officials have claimed, where did they miss the boat? It appears they disregarded the tenants of Problem Solving 101! Problem Solving 101 dictates that the following steps occur: 1. Understand the situation 2. Identify the root cause of the problem 3. Develop an effective action plan 4. Execute and modify until the problem is solved. 38 The missing step in New York is Step #2 Identify the root cause of the problem. According to city health department sources, New York City health officials said water supplies in buildings linked to the outbreak in the Bronx were unaffected by legionella without ever testing the water systems. Neither the buildings with cooling towers that tested positive for legionella, nor the workplaces or residences of the New Yorkers with confirmed cases of the disease had their

13 water supplies sampled for the infectious bacteria, even when there were multiple cases in the same building! This means officials could not know for sure if the people in those buildings were safe. A highly questionable choice given the current understanding of disease transmission. This is a sentiment echoed by Dr. Stephen Edberg of Yale University, when he stated about the recent Bronx outbreak, If you don t test for it, it s ridiculous. 39 This current investigation bias in Legionnaires disease outbreaks is similar to the London cholera outbreak of John Snow lived from He was an English physician and is now considered to be the father of modern epidemiology. He played a pivotal role in diagnosing potable water as the source of a Cholera outbreak in London in While now considered straight forward and logical, his theories were considered to be quite radical at the time. 40 In 1854 John Snow constructed this map showing deaths by cholera in the SoHo section of London. This map clearly shows a random grouping of deaths around a public water pump on Broad street. Snow questioned residents of the area and found that there was no prevalence of cholera EXCEPT among those who were in the habit of drinking from that particular well. He then proposed that the source of cholera was that well. Clinging to the old paradigm, this rational conclusion was ignored. The most widely accepted theory for the spread of cholera was the Miasma Theory that held that disease was spread by the bad airs emanating from decaying material. Finally 8 years after Snow s death it was accepted that water was the true source for cholera disease spread and not air.

14 41 The miasma theory was so strongly rooted that all evidence to the contrary was deemed merely coincidental The AIR SMELLS BAD therefore it must be the cause; the water tastes fine it cannot be the cause. This case is the perfect example of Investigation Bias. 42 We have seen many cases of this bias throughout history and myth busting is never easy. From the belief that the Earth is Flat, to the certainty that the Earth is the Center of the Universe, when science disproves the current theory rarely is it immediately accepted by political powers or the general public. Altering the public s opinion that Legionnaires disease outbreaks are usually caused by bad airs from modern cooling towers is proving to be just as difficult. 43 The other concept that the Cholera outbreak demonstrates is that potable water outbreaks have no spatial gradient. Meaning there is no reduction in case concentration centered around a common point. Disease incidence is seemingly random but all related to a single water distribution system. 44 A more recent potable waterborne infection occurred in Denmark in 2007 with an outbreak of gastroenteritis. On the map, the red dots are reported cases. Investigation showed contamination of one part of the water distribution system, while other parts of the system appeared to be unaffected. The source was eventually identified as backflow of sewage into an infected portion of the drinking water system. The red box is the area supplied with contaminated drinking water. The blue line is the area supplied by water from the local waterworks. As you can see, once all of the relevant information is available a pattern to the cases emerges.

15 45 In both of these examples, cases are clustered in the affected area, but there is no spatial gradient from a point. The cases occur randomly in the affected area. A potable system is colonized and emits pathogenic bacteria from many exposure points. Either many devices within a building or from many buildings within a distribution system. So let s return to the map of the Bronx which shows a similar outbreak case distribution. Unlike an aerosol point source outbreak, there is no gradient with distance from the source. Rather, the cases appear randomly across a broad area, producing a case map with more similarity to the waterborne cholera and gastroenteritis outbreaks. 46 We have discussed that the New York outbreak more closely resembles a potable water outbreak than a single aerosol point source outbreak. We have also explained that the cooling tower in question had high efficiency drift eliminators with a very low drift rate. How then did the Public Health Officials select the Opera House Cooling Tower as the single source? While there are several cooling towers in the area, the Opera House Cooling Tower was specifically selected as the source because samples taken from several patients those shown by red circles matched the bacterial DNA from the cooling tower samples. What does that mean? 47 Determining the source of a particular outbreak requires gathering and analyzing large amounts of information. Patients are interviewed, commonality between sites visited by patients is evaluated, possible sources are examined, and an attempt is made to match the DNA of infectious bacteria grown from patient isolates to that found in the environment. It is only when ALL of these fall in line that a source of the disease can be positively identified.

16 48 Simply stated, the lack of a DNA match can disprove that a particular device is the source, 49 But a genetic match on its own without patient commonality cannot prove that it is the source. A particular strain is likely to be present throughout the potable water system. Cooling tower MU is fed from the building s potable supply. As we have already discussed in the Bronx outbreak, there is very little commonality between the alleged source cooling tower location and outbreak cases. 50 A perfect example of patient commonality being matched to bacteria genetics to find the actual source, occurred in South Dakota in A cluster of Legionnaires disease was uncovered in Rapid City, South Dakota. Looking at the map, the patients are shown as red stars and the black boxes are areas where the patients frequently spent time. There was only a weak correlation with patients spending more time near a cooling tower than the general public. However, the initial hypothesis was that a nearby cooling tower was the source, and 43 cooling towers in the area were sampled. Isolates, or samples of Legionella bacteria, were successfully grown from four of the patients. The patients sample DNA matched each other but did not match any of the cooling towers.

17 Continued investigation showed that 83% of the infected individuals recalled eating in a particular restaurant, shown by the grey square on the map, during their likely infection period. 51 A very small decorative fountain in the restaurant was sampled and found to be contaminated with Legionella that had a DNA match to the patients isolates. While the actual source was positively identified, this outbreak would likely have been attributed to a cooling tower if the isolate genetics had been inconclusive or if one of the sampled cooling towers contained bacteria that were a genetic match to the patients. If this had happened, Investigation Bias would have allowed additional people to become sick. With that in mind, let s go back to the outbreak in New York. 52 It is important to know that the outbreak in the Bronx actually occurred in 3 parts. We have already covered the initial outbreak. 53 The second outbreak occurred in the Melrose Houses. The final outbreak was in Morris Park. These last two outbreaks are worth discussing as they not only highlight the fact that legionella was present in building water systems in the Bronx, they also make it easy to conclude that the proposed New York regulations, as they currently stand, are ineffective. Melrose Houses are a New York public housing complex located 0.4 miles from the Opera House Hotel.

18 54 This is a chart of number of Legionnaires disease cases by date. The blue columns are the initial outbreak cases. The red columns are the Melrose House outbreak cases. The first diagnosis in the Melrose Houses outbreak occurred in March 2015 and, being sporadic, was not investigated at that time. Two more cases occurred during the initial outbreak in July and were originally included in that investigation. BUT the final case, the 4 th in the same Melrose House building, occurred in late August AFTER the initial outbreak was declared to be over. 55 Because the city had already declared the end of the initial outbreak, the 4 th case was deemed significant enough to warrant testing of the potable water sources. Until that time, no potable water testing had occurred. After testing, the New York City Department of Health found the actual source of the infection to be the potable hot water. Point of use water filters were installed on all faucets and showerheads, and a copper silver ionization system was installed in the buildings potable water piping. 56 Dr. Victor Yu, one of the primary authors of the original 1982 New England Journal of Medicine article was quoted during the initial outbreak in the Bronx. He said legionella outbreaks virtually always stem from a building s drinking water supply. Dr. Yu stated, You ve got to look at the water. Legionella is actually coming through the city water supply, but in very low numbers. At the same time as the New York Department of Health said the The drinking water is unaffected. Dr. Yu said They have identified the wrong source. And Dr. Yu was correct!

19 57 A third outbreak of Legionnaires disease occurred in the Morris Park neighborhood of the Bronx. Morris Park is about 4 miles from the Opera House Hotel in the East Bronx. There were 13 cases in this outbreak and 1 death. The timing of this outbreak is what makes it so important. 58 This is a compilation of the epidemic onsets of disease provided by the NYC Department of Health for all 3 Bronx outbreaks. The blue columns represent the daily cases during the initial outbreak in the South Bronx. The red columns represent the cases from the potable water outbreak at the Melrose Houses (the first case in March is not shown). The green columns represent the cases from the third outbreak at Morris Park. On August , in response to the initial outbreak, the Health Commissioner issued an order for inspection and disinfection of all cooling towers in NYC. From Aug 6 to Aug 27 All towers in NYC were disinfected per the emergency regulations. The onset of symptoms for the first cases in what was to be the Morris Park outbreak occurred on September 14 th. The infection period for those cases was September 4 th to September 12 th. Calculated infection dates were only 2 4 weeks after all NYC cooling towers were disinfected. On Sept 29, 15 area cooling towers were disinfected again. From this time line it is clear that the mandated cooling tower cleaning after the initial outbreak which cost millions of dollars and greatly disrupted building owners, had both no effect on the initial outbreak which had already ended and no effect at preventing the Morris Park outbreak Not only is the city mandating actions that have demonstrated no effect on limiting disease but the actions are expensive and disruptive.

20 59 So clearly, disinfecting the cooling towers did not prevent an outbreak of Legionnaires Disease. Logic would follow that the proposed New York City Regulations, which focus only on cooling towers, have not been effective and will not be effective. So let s take a look at Europe where strict regulations designed to eliminate Legionella in cooling towers have been in place for more than 10 years. 60 France provides an interesting study of the effects of cooling tower regulations designed to reduce the incidence of Legionnaires disease. In the winter of 2003 to 2004 a large outbreak occurred in Pas de Calais, France. An industrial cooling tower was implicated as the source for the contamination. As a result of this outbreak regulations were issued for the control of cooling towers. The 2004 regulation focuses solely on cooling towers. It mandates frequent testing of cooling towers for Legionella monthly testing unless 12 consecutive tests are less than 1 CFU/ml then the testing can be reduced to quarterly. 61 But here s the rub Following an increase due to improved testing and reporting in the early 2000 s, the incidence rate for Legionnaires' disease infection in France has been hovering around 2 per 100,000 of population for over a decade. A reduction in Legionnaires' disease incidence has not been observed since the regulations were implemented. These results indicate that the cooling tower specific regulations had little to no effect on the incidence of Legionnaires disease.

21 62 Expanding the graph to other European countries such as Italy, Belgium, UK, and the Netherlands, which have similar Legionella regulations to France shows there is little difference in the incidence rate between Western Europe and the United States in spite of burdensome regulation on cooling towers which have been in place in Europe for many years. 63 So we started the presentation with a question and the evidence is compelling. Yes, the new regulations clearly have missed the boat. This is New York s watershed moment the opportunity to lead not just the city and state but the nation into a new era of Legionnaires disease prevention. The question is, where do we go from here? 64 Everyone is in agreement, the overriding goal is to reduce population exposure to Legionella thus reducing illness and death. In order to make that happen, we clearly need to change our investigative practices. More importance must be placed on understanding the source of the sporadic 96% of Legionnaires' disease cases. And, all potential sources of Legionella, including potable water and building water supplies, must be investigated when an outbreak occurs. 65 In addition to better investigations, a broader approach to prevention is required. The WHO, EPA, CDC, OSHA, VHA and other government agencies all focus on the entire building water system, including the potable water system, in their Legionella prevention recommendations. Regulations should be revised or written that address proper maintenance and monitoring of all potential sources.

22 66 Implementing ASHRAE Standard 188 in its entirety, not just the convenient parts as well as ASHRAE Guideline 12 is the answer. The purpose of the Standard is not to minimize the risk for SOME building water systems but for ALL high risk building water systems. 67 These documents were developed by a diverse group of experts, some of whom are here today, who understand the complete scope of the Legionnaires disease problem. There is no reason for law makers to start over creating new regulations when the informed and complete solution is already available. Thank you for your attention. Are there any questions?