Misplaced Pages

#642357

101-495: Subsequently, Associate Chief Justice of Ontario, Dennis O'Connor led an inquiry into the outbreak, called the Walkerton Inquiry . Walkerton Public Utilities Commission operators Stan and Frank Koebel, neither of whom had any formal training, were sentenced on December 20, 2004, after pleading guilty to charges of common nuisance stemming from the contamination—Stan to one year in jail, and Frank to nine months house arrest. As

202-481: A halogen , chlorine is a highly efficient disinfectant, and is added to public water supplies to kill disease-causing pathogens, such as bacteria , viruses , and protozoans , that commonly grow in water supply reservoirs, on the walls of water mains and in storage tanks. The microscopic agents of many diseases such as cholera , typhoid fever , and dysentery killed countless people annually before disinfection methods were employed routinely. By far most chlorine

303-538: A chlorine-generating filter that electrolyzes common salt . Pools chlorinated by this method generally have lower levels of chlorine than directly chlorinated pools. Such pools are called saltwater pools. Disinfection by chlorination can be problematic in some circumstances. Chlorine can react with naturally occurring organic compounds found in the water supply to produce compounds known as disinfection by-products (DBPs). The most common DBPs are trihalomethanes (THMs) and haloacetic acids (HAAs). Trihalomethanes are

404-568: A commissioner of the Walkerton and Arar inquiries." In 2016, he was made a member of the Order of Ontario . This article about Canadian law is a stub . You can help Misplaced Pages by expanding it . Water chlorination Water chlorination is the process of adding chlorine or chlorine compounds such as sodium hypochlorite to water . This method is used to kill bacteria, viruses and other microbes in water. In particular, chlorination

505-522: A fair bit of construction and there is some concern – I'm not sure, we're not finding anything ... but I am doing this [flushing and chlorinating] as a precaution ... Christopher Johnston : So you haven't had any adverse samples then? Stan Koebel : We've had the odd one, you know, we're in the process of changing companies, because the other company, it closed the doors, so we are going through some pains right now to get it going. Excerpt from May 20th telephone conversation between Stan Koebel, of

606-574: A grandfathering program run by the Ministry of the Environment (MOE) and based on their work experience in their positions. Though Ontario law required that water systems operators receive 40 hours of continuing education per year, Stan Koebel interpreted this to include activities only marginally related to water systems, such as CPR certification, and as a result neither brother used continuing education time to gain or maintain expertise in water safety. As

707-543: A large scale, as for service water carts." Major Carl Rogers Darnall , Professor of Chemistry at the Army Medical School , gave the first practical demonstration of this in 1910. This work became the basis for present day systems of municipal water purification . Shortly after Darnall's demonstration, Major William J. L. Lyster of the Army Medical Department used a solution of calcium hypochlorite in

808-399: A linen bag to treat water. For many decades, Lyster's method remained the standard for U.S. ground forces in the field and in camps, implemented in the form of the familiar Lyster Bag (also spelled Lister Bag). The canvas "bag, water, sterilizing" was a common component of field kitchens, issued one per 100 persons, of a standard 36-gallon capacity that hung from an often-improvised tripod in

909-449: A month." Both men felt that Walkerton water was adequately pure and safe without a 0.5 mg/L chlorine residual—they were known to willingly drink raw water from the wells—and they had received complaints from community members about system water tasting overly chlorinated. The PUC's evaluation of chlorine residual levels was typically performed weekly, rather than daily, and actual testing was often eschewed in favour of visually inspecting

1010-756: A pattern, and no report was made to the Bruce-Grey-Owen Sound Health Unit, which was responsible for public health in Grey and Bruce counties. On May 18, twenty students were absent from the Mother Teresa School in Walkerton; the next day, twenty-five were, with a further four sent home from Mother Teresa and eight sent home from the Walkerton Public School. The increasing number of community illnesses became even more noticeable on May 19, when

1111-703: A pediatrician and a retirement home both reported outbreaks of gastroenteritis among their charges. By May 20, the Walkerton hospital had fielded calls from more than a hundred people about incidents of gastroenteritis in the town, and attended to dozens more in their Emergency Department. Attending physicians and health care workers, aware that the gastroenteritis symptoms they were seeing were consistent with possible E. coli infection, began collecting stool samples from affected patients. When public health officials put together common reports, they found that three area hospitals had recorded incidents of patients suffering from gastroenteritis symptoms. Walkerton's hospital recorded

SECTION 10

#1732855267643

1212-461: A physical source of the infection; when affected patients' residences were mapped, their distribution across a map of Walkerton showed no immediately apparent pattern, with affected populations present in all areas served by Walkerton's water system. By that evening, public health investigators had concluded based on patient interviews and demographic mapping that the water system was the most likely vehicle of infection, despite their not being aware of

1313-435: A problem in Walkerton. The meeting became heated, with McQuigge urging Stan Koebel to "come clean", Koebel refusing to disclose adverse test results, and McQuigge and Mayor Thompson exchanging confrontational words as the meeting broke up. McQuigge later claimed that he had urged Thompson to "tell the public what you know"; Thompson alleged that McQuigge had threatened him if he "bl[e]w the whistle on me or Brockton". Later in

1414-649: A result of their lack of formal training and their overseeing themselves, the Koebel brothers were relatively uninformed about water safety. Both later testified that they were not familiar with sections of the Ontario Drinking Water Standards documentation (ODWS) that dealt with tasks they needed to be aware of to do their jobs adequately: manager Stan Koebel had not read the section of the ODWS about identifying contaminated water, while foreman Frank Koebel had not read

1515-477: A result, stricter water treatment guidelines were put in place by the government. Walkerton, Ontario is a small township in the municipality of Brockton , 180 kilometres (110 mi) northwest of Toronto . It serves as the administrative centre of Brockton, into which it was merged in 1999, and as the county seat of Bruce County . The population of Walkerton in 1996 was recorded as 5,036 individuals in an area of 6.4 square kilometres (2.5 sq mi). At

1616-712: A serious and potentially deadly complication of E. coli infection. The full death toll for the outbreak was initially reported as seven, but later revised to six. Dennis O%27Connor (judge) Dennis R. O'Connor , OC OOnt was the Associate Chief Justice of Ontario from 2001–2012 and sat on the Court of Appeal for Ontario from 1998–2012. O'Connor attended De La Salle College and Osgoode Hall Law School of York University in Toronto. He practised law from 1973 until 1976. From 1976 to 1980 he became

1717-636: A teacher at the University of Western Ontario Faculty of Law and from there went to practise litigation at Borden, Elliot in Toronto. He was a negotiator for the Government of Canada in the Yukon land claim debate. He was eventually appointed to the Ontario Court of Appeal in 1998 and was elevated to Associate Chief Justice of Ontario in 2001. He was appointed Commissioner in the Walkerton Inquiry in 2000, and

1818-586: A variety of Walkerton-centred government and management bodies, including the Walkerton Public Utilities Commission (PUC). Shortly after the definitive laboratory results were received, McQuigge, representing BGOSHU, contacted David Thompson, the mayor of Brockton, Walkerton's parent municipality. According to McQuigge, the conversation involved McQuigge alerting Thompson to the fact that community members were falling ill with potentially fatal E. coli infections; according to Thompson, E. coli

1919-405: Is manufactured from table salt (NaCl) by electrolysis in the chlor-alkali process. The resulting gas at atmospheric pressures is liquified at high pressure. The liquefied gas is transported and used as such. As a strong oxidizing agent , chlorine kills via the oxidation of organic molecules. Chlorine and the hydrolysis product hypochlorous acid are not charged and therefore easily penetrate

2020-548: Is performed by mixing a large amount of hypochlorite into the water. The hypochlorite can be in the form of a powder or a liquid such as chlorine bleach (solution of sodium hypochlorite or calcium hypochlorite in water). Water that is being shock chlorinated should not be swum in or drunk until the sodium hypochlorite count in the water goes down to three parts per million (PPM) or until the calcium hypochlorite count goes down to 0.2 to 0.35 PPM. As an alternative to shock chlorination, some swimming pools are chlorinated by use of

2121-480: Is used to prevent the spread of waterborne diseases such as cholera , dysentery , and typhoid . In a paper published in 1894, it was formally proposed to add chlorine to water to render it "germ-free". Two other authorities endorsed this proposal and published it in many other papers in 1895. Early attempts at implementing water chlorination at a water treatment plant were made in 1893 in Hamburg , Germany. In 1897

SECTION 20

#1732855267643

2222-547: The United States for disinfection took place in 1908 at Boonton Reservoir (on the Rockaway River ), which served as the supply for Jersey City, New Jersey . Chlorination was achieved by controlled additions of dilute solutions of chloride of lime ( calcium hypochlorite ) at doses of 0.2 to 0.35 ppm. The treatment process was conceived by John L. Leal , and the chlorination plant was designed by George Warren Fuller. Over

2323-482: The "bubble" on the chlorinator for a "guesstimate" of the residual. These "guesstimates" would be noted in the PUC's daily operating sheets as if they were actual tested levels. When actual testing was performed, the 15-minute timeframe of the test was often cut short, resulting in higher-than-reality chlorine residual readings. Fecal coliform and E. coli testing on Well 5 between 1990 and 2000 showed ongoing deterioration in

2424-777: The BGOSHU contacted the Minister of Health and the Chief Medical Officer of Health of Ontario. Requests were placed with the Ministry of Health for an epidemiologist and for staff to assist in treating Walkerton-region gastroenteritis patients; public health staff began looking into acquiring equipment that would be needed to treat any E. coli patients whose infections progressed to Hemolytic-Uremic Syndrome (HUS). David Patterson ordered further testing of Walkerton's water, sending James Schmidt to collect samples of water from various sources in Walkerton, including "food premises, hospitals, and

2525-678: The Environment (MOE) employee Philip Bye, who had been notified by Bruce-Grey-Owen-Sound Health Unit (BGOSHU) phone call the previous evening, did not understand that E. coli contamination was a life-threatening emergency; he took no action until he was contacted again later on May 22 by a concerned Dr. McQuigge. At that point, Bye sent an environmental officer to join the investigation in Walkerton. The MOE environmental officer dispatched by Bye, John Earl, spoke first to David Patterson (the Assistant Director of Health Protection at BGOSHU), who expressed his growing suspicion that Walkerton PUC water

2626-550: The Highway 9 project's consulting firm, it was decided that Burns's firm would develop an action plan to remediate the water contamination. On the basis of this remediation plan, meeting participants decided that it would not be necessary to declare a state of emergency in Walkerton. Despite this declaration, publicizing of the epidemic, and the Boil Water Advisory, local hospitals continued to treat gastroenteritis patients during

2727-451: The MOE would be investigating the ways in which Walkerton's water system could have become the cause of the outbreak. McQuigge, in response to questions, asserted that he did not believe the public could have been notified with a Boil Water Advisory any earlier than they were; prior to May 21, neither the distribution of hospital admissions nor then-current testing results supported publicly declaring

2828-500: The May 15 test results to the chairman of the Board of Health and to Dr. Murray McQuigge, the local Medical Officer of Health. Shortly after 11 a.m., a press conference was held at the Walkerton hospital. Led by McQuigge and attended by hospital staff, BGOSHU staff, and the media, this press conference was the first reliable report to the public of the existence and causes of an E. coli outbreak in

2929-418: The May 17 testing results, but notified no one else of these results. After Earl left the PUC, Stan Koebel contacted his brother Frank to ask him to "clean up" the pumping log for Well 7. Stan Koebel hoped to have a new document to present to Earl the next day that would not reflect that Well 7 had been unattended to and unchlorinated. Frank Koebel complied with this request. He destroyed the previous version of

3030-447: The May 21 samples, and though testing was not complete on the May 22 samples, evidence of coliform growth was already apparent. John Earl (the Ministry of the Environment (MOE) environmental officer) returned to the Walkerton Public Utilities Commission (PUC) that morning to continue his investigation. Stan Koebel, the PUC manager, gave him the Well 7-related documents that he and Frank Koebel,

3131-404: The Ministry of the Environment (MOE) that "we've had the odd [adverse sample]" due to previous construction work but that the system flushing was occurring only as "a precaution". The MOE employee who spoke to Koebel believed that this meant any adverse samples of Walkerton water were in the past, and filed his subsequent report of the conversation accordingly; Koebel had again failed to note that he

Walkerton E. coli outbreak - Misplaced Pages Continue

3232-590: The Owen Sound Hospital; when health officials contacted other hospitals in the Bruce-Grey system, they found that all were handling patients with gastrointestinal ailments consistent with E. coli infection. Potential E. coli infection changed the treatment plan for patients reporting to these hospitals or to local doctors; anti-motility medication that would typically be prescribed to patients suffering from diarrhea unrelated to E. coli could in fact exacerbate

3333-513: The PUC foreman, had falsified, and Earl began to analyse the documentation he had collected over the past few days. He noted apparent irregularities in the pumping histories of all three wells, as well as unlikely chlorination levels recorded for Well 5. He communicated these irregularities to the MOE's Philip Bye, but neither man reported them outside of his own organization. At 9:45 on the morning of May 23, David Patterson (the Assistant Director of Health Protection at BGOSHU) contacted Stan Koebel at

3434-842: The Walkerton PUC about the possibility of the water system being involved in transmission of the gastroenteritis; they were told that the town's drinking water was "okay". After speaking to public health officials that day, Stan Koebel (PUC manager) began the process of flushing the system and increasing chlorination levels, procedures he described to David Patterson as "precautionary". This flushing continued into May 20; Koebel's testing records from that day note sharply increased chlorine residual levels, though evidence later indicated that Koebel's testing had likely been done improperly and thus returned higher-than-reality chlorination results. The same day, Koebel returned Well 5, which had not been feeding Walkerton's water supply since May 15, to service. The well

3535-419: The Walkerton PUC and informed him of the May 21 test results. Koebel, realizing that his attempts to clean the system beginning May 19 had not been sufficient, confessed to Patterson that he had been aware of the contamination of Walkerton water since May 17. Koebel was reportedly "distraught" at this point in the conversation. After ending his call with Koebel, Patterson immediately passed on the information about

3636-437: The Walkerton PUC, however, was to comply with an earlier governmental requirement of nine samples per month. Employees were instructed to collect four weekly samples from each of the three wells that served Walkerton. This meant that even in an ideal month, the PUC typically submitted one fewer sample than required by law; in practice, it was more common for eight or nine samples to be submitted than for thirteen to be. In addition,

3737-452: The Walkerton PUC. The men discussed the PUC's assurances that their water was safe, and the call ended with no action. Shortly afterward, however, Patterson contacted Stan Koebel, the manager at the Walkerton PUC again. Koebel expressed dismay at the Boil Water Advisory and the fact that the PUC had not been notified of it beforehand. He asked Patterson's advice for the best next steps to take; Patterson suggested increasing chlorination levels in

3838-413: The Walkerton Public Utilities Commission (PUC) since the 1970s, when they were teenagers and their father worked at the PUC. Neither man had formal training in public utility operation or in water management, but by 2000, both had been promoted to management positions on the basis of their experience. Both brothers carried certification as class 3 water distribution system operators, licences obtained through

3939-412: The Walkerton Public Utilities Commission, and Christopher Johnston, of the Ministry of the Environment. On May 20, Robert McKay, a PUC employee who was on medical leave at the time, anonymously contacted the Ministry of the Environment's Spills Action Centre (SAC) to report potential issues with the Walkerton water supply; after observing fire hydrants being used for system flushing, he had concluded that

4040-483: The afternoon, Thompson and the council convened a private meeting without BGOSHU staff to decide their next steps. Stan Koebel told meeting participants that testing had shown bacteriological issues in Wells 5 and 7; explaining, Well 7's chlorinator had not been functioning properly, he did not disclose that Well 7 had in fact been operating without any chlorinator at all. With the input of Koebel and Steve Burns, an engineer with

4141-612: The bacteria deeper into the soil near Well 5. During later investigations of the outbreak, experts on the Walkerton Commission Expert Review Panel determined that the manure-contaminated water had likely seeped into the aquifer that underlay Well 5, though it may have been possible that surface runoff, rather than contaminated groundwater, was the source of the bacteria. Cattle manure, even under best practices, typically contains fecal coliform bacteria, including E. coli . A subsequent government report concluded that

Walkerton E. coli outbreak - Misplaced Pages Continue

4242-643: The burden from his shoulders. Stan and Frank Koebel again spent part of their day on May 21 flushing the system. At 2:30 p.m. on May 21, the BGOSHU convened a strategic response team to handle the outbreak. After discussion, the team decided to directly notify at-risk or involved institutions, including hospitals, of the Boil Water Advisory. The Walkerton hospital received its notification at 3:30 p.m. that day. Prior to this, and despite numerous contacts with BGOSHU staff, hospital personnel had not been aware of potential danger from Walkerton water; in some cases hospital personnel had been told specifically that water

4343-612: The cattle operation had followed all safety and husbandry best practices with regard to manure storage and use, and that though the E. coli contamination had almost certainly come from the farm's manure usage, the farm's operator was not at fault for contamination of the well. Beginning May 17, 2000, absenteeism in the Walkerton school system took an upswing. That day, the Walkerton Hospital treated seven children suffering from gastrointestinal ailments involving cramping and diarrhea. The illnesses were not initially recognized as part of

4444-512: The cattle was used to fertilize crops growing on lot 20 of the property, the nearest edge of which lay approximately 81 metres (266 ft) from Well 5. The manure was subsequently incorporated into the soil of lot 20 using a disc harrow . The April incorporation of E. coli -contaminated manure into cool, wet soil near Well 5 meant that the bacteria were in an ideally suited environment for longevity. Subsequent heavy rains totalling 134 millimetres (5.3 in) fell between May 8 and May 12, drawing

4545-559: The chapter on chemical testing of water for safety purposes. Neither man had more than a passing familiarity with E. coli or the danger the bacteria posed to water systems, nor with chlorination standards and best practices. The wells that drew water for Walkerton were known as Well 5, Well 6, and Well 7, with Well 5 being both the southernmost and the closest to the residential portion of the township. Well 5, drawing water from depths of 5.5 to 5.8 metres (18.0 to 19.0 ft) and 7.0 to 7.3 metres (23.0 to 24.0 ft) through soft limestone,

4646-469: The community. The Walkerton hospital hosted a roundtable at 1 p.m. the same day to inform local physicians of proper treatment for E. coli O157:H7 -associated gastroenteritis, especially with regard to infected children, who were at increased risk for renal failure due to Hemolytic-Uremic Syndrome. Shortly thereafter, BGOSHU staff met with the Brockton city council in the council's chambers. This meeting

4747-513: The condition of patients whose diarrhea was due to E. coli infection, and any patient infected with E. coli O157 was at risk for potentially fatal hemolytic-uremic syndrome . David Patterson, the Assistant Director of Health Protection at Bruce-Grey-Owen-Sound Health Unit (BGOSHU), immediately contacted Beverly Middleton, a public health inspector in the Owen Sound office of the Health Unit, and

4848-567: The corroborating documents that John Earl had collected. They began notifying branch offices of the BGOSHU of the outbreak and its cause. The Bruce-Grey-Owen-Sound Health Unit (BGOSHU)'s May 22 presumptive conclusion about Walkerton's water was confirmed at 8:45 the following morning, when the London Regional Public Health Laboratory reported testing results on the water Schmidt had collected on May 21 and 22: both E. coli and fecal coliform results had come back positive on

4949-456: The distribution system were 0.1 to 0.4 parts per million; based on lack of familiarity with water chlorination, Patterson concluded that the presence of chlorine residuals at any level indicated that the water system was free of contamination. He proceeded with investigating other possible sources for the E. coli . Throughout May 20, Patterson expressed his understanding to community members and other investigators that Walkerton's water could not be

5050-427: The document and created a new one with fictitious data: the new document showed Well 7 as not having operated on the days it had actually been pumping unchlorinated water into the system, and contained chlorine residual records for Well 7 which were entirely fictitious. Frank Koebel later testified that he had falsified this document "so it would look better to the MOE". While the Ministry of the Environment investigated

5151-419: The existence of the outbreak or the fact that it presented a real and present danger to public health. Mayor David Thompson, himself suffering from symptoms of gastroenteritis, which he assumed to be flu , took no investigatory or emergency-preparedness action on May 22, nor did James Kieffer, chair of the Walkerton Public Utilities Commission (PUC), who had been alerted to the outbreak the day before. Ministry of

SECTION 50

#1732855267643

5252-853: The field. In use from World War I through the Vietnam War, it has been replaced by reverse osmosis systems that produce potable water by pressure straining local water through microscopic-level filters: the Reverse Osmosis Water Purification Unit (1980) and the Tactical Water Purification System (2007) for large-scale production, and the Light Water Purifier unit for smaller-scale needs that includes ultrafiltration technology to produce potable water from any source and uses automated backwash cycles every 15 minutes to simplify cleaning operations. Chlorine gas

5353-423: The first emergence of symptoms in the community, investigators determined that the majority of infected community members had been exposed to the bacteria between May 13 and May 16 and the contamination had thus likely entered the infective well on or about May 12. In the spring of 2000, Walkerton's system typically drew most of its water from one well at a time, alternating unevenly between wells 5, 6, and 7. Well 7

5454-467: The flushing may have been related to the ongoing illness outbreak in the community and felt that he needed to report his conclusion. McKay also reported to the SAC that Walkerton water had failed "lab tests", but he was unable to provide detail about what aspect of the water quality had caused the failure. Later in the day on May 20, McKay attempted to contact the Ministry of Health directly about his suspicions, but

5555-423: The health inspectors to whom he spoke on May 19 or May 20 any information about known adverse test results or the fact that he knew Well 7 had been providing unchlorinated water to the system from May 15 to May 19. O'Connor's report interpreted this not as an act of accidental omission, but as a deliberate attempt by Koebel to conceal what he knew to be substandard and potentially unsafe practices in his department. At

5656-429: The health unit office". Patterson received Schmidt's collected samples and drove them to London overnight. The samples were received by the London Regional Public Health Laboratory at 12:45 a.m. on May 22; a further round of sampling was ordered to be done the next day. Despite increased awareness of the severity of the outbreak, as May 22 began, some links in the public safety chain were still uninformed as to either

5757-428: The highest number of such patients, with at least twenty patients visiting the emergency department with bloody diarrhea on May 20, and two more patients admitted for diarrhea-connected dehydration. Hospitals in two neighbouring towns had each seen one case of bloody diarrhea. On May 20, early laboratory testing was completed on fecal samples submitted the day before. E. coli O157 was found in at least one sample from

5858-518: The immediate area of the well be limited in light of agricultural waste runoff being detectable in the well's water. Neither of these recommendations was implemented as conditions of operation when Well 5 received a Certificate of Approval in 1979. Multiple subsequent tests on the well between 1979 and 2000 continued to conclude that due to the shallow depth at which Well 5 was drilled and the tendency of its water level and makeup to be directly affected by surface runoff, caution toward contamination levels in

5959-498: The impression that the BWA was cautionary only, reported the advisory at roughly hourly intervals, beginning at 1:30 p.m., rather than more rapidly as they later stated they might have if the import of the announcement had been made clear to them at the time. As a result of the limited distribution of information regarding the BWA, much of the community remained unaware of the Boil Water Advisory until days after its May 21 issuance. Around

6060-527: The laboratory notified Stan Koebel on May 17 that submitted samples had tested positive for E. coli and fecal coliform. Personnel from the testing laboratory, unaware that Ontario Drinking Water Objectives mandated the notification of the Ministry of the Environment in such a case, did not notify any agency besides the PUC of the failed testing results. Using knowledge about typical incubation periods of E. coli O157:H7 (average 3–4 days) and Campylobacter (average 2–5 days) bacteria and working backwards from

6161-454: The last week of May at numbers more than double typical ER throughput. Hospital staff were forced to take emergency measures, with elective and deferrable treatments redirected to other hospitals and out-of-town medical staff being pressed into service. By May 24, there had been four patient deaths and the Walkerton hospital and the BGOSHU were playing host to three epidemiologists from various arms of Health Canada . 27 people had developed HUS ,

SECTION 60

#1732855267643

6262-481: The main disinfectant by-products created from chlorination. Their effects depend strictly on the duration of their exposure to the chemicals and the amount ingested into the body. In high doses, bromoform mainly slows down regular brain activity, which is manifested by symptoms such as sleepiness or sedation. Chronic exposure of both bromoform and dibromochloromethane can cause liver and kidney cancer, as well as heart disease, unconsciousness, or death in high doses. Due to

6363-408: The major species are Cl 2 and HOCl, whereas in alkaline solution, effectively only ClO ( hypochlorite ion) is present. Very small concentrations of ClO 2 , ClO 3 , ClO 4 are also found. Shock chlorination is a process used in many swimming pools, water wells , springs , and other water sources to reduce the bacterial and algal residue in the water. Shock chlorination

6464-425: The negatively charged surface of pathogens. It is able to disintegrate the lipids that compose the cell wall and react with intracellular enzymes and proteins , making them nonfunctional. Microorganisms then either die or are no longer able to multiply. When dissolved in water, chlorine converts to an equilibrium mixture of chlorine, hypochlorous acid (HOCl), and hydrochloric acid (HCl): In acidic solution,

6565-401: The news on to the emergency response arm of the MOE that day. In the face of rising community casualties—by the evening of May 21, 270 people had contacted the Walkerton hospital after experiencing gastroenteritis symptoms, and one patient had had to be airlifted to London, Ontario , for treatment—the situation was being perceived as increasingly serious by most of those involved. That evening,

6666-589: The next few years, chlorine disinfection using chloride of lime (calcium hypochlorite) was rapidly implemented in drinking water systems around the world. The technique of purification of drinking water by use of compressed liquefied chlorine gas was developed by a British officer in the Indian Medical Service , Vincent B. Nesfield, in 1903. According to his own account, "It occurred to me that chlorine gas might be found satisfactory ... if suitable means could be found for using it.... The next important question

6767-610: The outbreak from the procedural end, public health officials swung into a medical investigation. Early epidemiological investigation had demonstrated fairly strongly that infection risk seemed to correlate to physical presence in Walkerton—even for patients visiting other area hospitals, investigators typically found that the patient lived in or had visited Walkerton during the period of their infection— and investigators now began making telephone calls to patients, gathering information about onset of symptoms, possible methods of exposure, and

6868-451: The outbreak was continuing and that no reliable information was yet available about the source of the contamination, the BGOSHU issued a cautionary Boil Water Advisory (BWA) to the community, to be distributed via local radio stations only. Local television stations were not contacted about the advisory, nor was national CBC Radio ; no paper version of the advisory was distributed to the community that day. Local radio station CKNX-FM , under

6969-474: The patients' personal demographic information. A compilation of data from this secondary investigation demonstrated that most patients had an onset of symptoms within a fairly narrow window of time, with the highest rate of onset occurring on May 17. Taking into account the incubation period of E. coli infection, the medical team determined that most patients had been exposed to the pathogen between May 12 and May 14. Investigators had less luck trying to pinpoint

7070-542: The potential carcinogenicity of these compounds, drinking water regulations across the developed world require regular monitoring of the concentration of these compounds in the distribution systems of municipal water systems. The World Health Organization has stated that "the risks to health from these by-products are extremely small in comparison with the risks associated with inadequate disinfection". There are also other concerns regarding chlorine, including its volatile nature which causes it to disappear too quickly from

7171-705: The quality of water from the well. In the mid-1990s, a provision for more intensive monitoring of wells susceptible to groundwater contamination was added to the Ontario Drinking Water Objectives (ODWO); however, the Ministry of the Environment (MOE) failed to apply this provision to reclassifying existing wells. As a result, despite tests repeatedly showing that Well 5 was prone to contamination, it did not have any contamination alarms or emergency shut-off mechanisms. April 2000 sampling done on water from Wells 5 and 6 showed fecal coliform present in Well 5's water, both raw and treated, but not in Well 6's. Well 7

7272-436: The same time, however, Koebel continued to consume PUC-served water and allow his family to do the same with no apparent concern about its safety; O'Connor concluded that while Koebel knew the system was contaminated, he did not understand that the E. coli bacteria causing the contamination were potentially deadly. Christopher Johnston : I just want to inquire and find out what's going on, that's all. Stan Koebel : We had

7373-419: The samples that were submitted often had their points of origin mislabelled; for the sake of convenience, testing employees might draw two samples from one location but label the bottles as having come from two locations, or draw a water sample from the water supply of their own home rather than from within distribution points of the system. As a result, not all water sources were being tested adequately, and there

7474-545: The source of the gastroenteritis outbreak. By 12 p.m. on May 21, however, laboratory results had confirmed enough cases of E. coli O157 in area gastroenteritis patients to merit a declaration by the Bruce-Grey-Owen-Sound Health Unit (BGOSHU) that an infective outbreak existed and was being caused by E. coli O157 contamination somewhere. The Health Unit issued an outbreak number and alerted neighbouring health units of its situation, as well as notifying

7575-449: The source of the outbreak; BGOSHU personnel also urged the PUC to issue a press release assuring the public of the safety of the water. By May 18, rumours were already circulating that Walkerton Public Utilities Commission (PUC) water was the cause of the illness increasing numbers of residents were suffering. Staff at the PUC had also begun receiving calls enquiring as to the safety of town water. On May 19, public health officials contacted

7676-562: The standard of collection in Walkerton. The PUC was again warned about noncompliance, and again Stan Koebel agreed to improve testing practices. MOE reports throughout the 1990s also noted that the PUC was inadequately chlorinating water that ran through the Walkerton system. Best practices dictated that chlorine residual levels after fifteen minutes of contact between the chlorine and the water be maintained at 0.5 mg/L, with that level verified through daily testing; this would indicate that

7777-489: The system. The same afternoon, the Spills Action Centre contacted Stan Koebel (the PUC manager) directly to discuss the ongoing events; Koebel once again failed to mention prior known adverse testing results. In later testimony, he acknowledged that this had been a deliberate omission; the O'Connor report concluded that Koebel had been hoping that when new samples were collected on May 23, they would test clean and lift

7878-437: The time of the 2000 events, the town's drinking water was drawn from three chlorinated wells to the west and southwest of the town. The wells were owned and operated by the Walkerton Public Utilities Commission (PUC), which was managed by Stan Koebel and run by foreman Frank Koebel. In 2000, the Walkerton Public Utilities Commission was under the supervision of two men, brothers Stan and Frank Koebel. Both men had been working for

7979-407: The time the BWA was first being broadcast, David Patterson (the Assistant Director of Health Protection at BGOSHU) contacted the MOE's Spills Action Centre (SAC) to officially report an E. coli outbreak in Walkerton. Paul Webb, the SAC employee taking Patterson's phone call, mentioned that they had previously been contacted by an anonymous source (Robert McKay) about the quality of water coming out of

8080-571: The town of Maidstone , England was the first to have its entire water supply treated with chlorine. Permanent water chlorination began in 1905, when a faulty slow sand filter and a contaminated water supply caused a serious typhoid fever epidemic in Lincoln , England. Alexander Cruickshank Houston used chlorination of the water to stop the epidemic. His installation fed a concentrated solution of so-called "chlorinated lime" (a mixture of calcium hypochlorite , calcium hydroxide and calcium chloride ) to

8181-503: The two officials began passing along information to local medical facilities about how to properly treat E. coli -based gastroenteritis. Later the same day, Patterson asked James Schmidt, Middleton's counterpart in the Walkerton Health Unit, to contact the Walkerton Public Utilities Commission (PUC) and obtain information on chlorination levels in the water system. Stan Koebel (PUC manager) informed Schmidt that chlorine residuals in

8282-406: The water being treated. This was not simply modern calcium chloride, but contained chlorine gas dissolved in lime-water (dilute calcium hydroxide) to form calcium hypochlorite (chlorinated lime). The chlorination of the water supply helped stop the epidemic and as a precaution, the chlorination was continued until 1911 when a new water supply was commissioned. The first continuous use of chlorine in

8383-524: The water system, and organoleptic concerns such as taste and odor. A dechlorinator is a chemical additive that removes chlorine or chloramine from water. Where tap water is chlorinated, it should be dechlorinated before use in an aquarium , since chlorine can harm aquatic life in the same way it kills micro-organisms . Chlorine will kill fish and cause damage to an aquarium's biological filter . Chemicals that serve this function are reducing agents which reduce chlorine species to chloride , which

8484-501: The water was being adequately purified of potentially harmful microorganisms. Inspections of the Walkerton system in 1991, 1995, and 1998 showed chlorine residual levels in the Walkerton system of between 0.12 mg/L and 0.4 mg/L, with a mean level of 0.27 mg/L. According to the later Walkerton Inquiry , "Stan Koebel testified that he generally set the chlorinator to slightly less than 0.5 mg/L and that Frank Koebel would lower it to approximately 0.3 mg/L several times

8585-451: The well had pumped unchlorinated water into the system for days. Earl requested and was given documentation regarding well testing, water distribution maps, and pumping history for the wells. Included in this documentation were records of the May 17 adverse testing results of May 15 samples from the "Highway 9" water main construction; excluded was pumping history for Well 7. Earl returned to the MOE with these documents and reviewed them, noting

8686-445: The well was advisable. Also, Wells 6 and 7 were drilled deeper and drew from areas of land with significantly less fractured bedrock than well 5. In 2000, Ontario law indicated that in a community the size of Walkerton, at least thirteen water samples per month should be submitted for microbiological testing, with the samples being drawn from "the point at which the treated water enters the distribution system". A longstanding standard at

8787-422: Was not the cause of the outbreak. The Ministry of the Environment nominally received notification of the outbreak from a message left on the home answering machine of employee Philip Bye. Bye, however, did not recognize the significance of E. coli being present in Walkerton water and, believing the measures public health officials had already taken to be sufficient to deal with the contamination, he did not pass

8888-521: Was Commissioner in the Maher Arar Inquiry from 2004 to 2006. On August 12, 2013, Toronto police chief Bill Blair announced that he had requested O'Connor conduct an internal review into the use of force by police. On June 30, 2016, O'Connor was made an Officer of the Order of Canada by Governor General David Johnston for "his service to the legal profession and for his commitment to justice as

8989-491: Was attended by representatives from the Ministry of the Environment and the Public Utilities Commission as well as of BGOSHU and the city council. The attendees of the meeting reviewed what was known thus far about the timeline of the outbreak, discussed what steps could be taken going forward, and attempted to analyse the adequacy of their response to the crisis thus far. MOE representative Philip Bye announced that

9090-446: Was aware of current test results that showed evidence of E. coli and fecal coliforms. Morning news reports on public radio on May 21 carried a statement by Dr. Murray McQuigge, Walkerton's Medical Officer of Health, reflecting medical investigators' then-current understanding that Walkerton's water system was presumed to be secure and not involved in the outbreak. McQuigge's quoted opinion also characterized E. coli as "unlikely" to be

9191-441: Was brought online to the Walkerton water system in 1978, following a hydrological evaluation commissioned by the PUC. Because Well 5's aquifer drew partially from spring-fed, gravel-soiled zones that were prone to absorbing surface runoff , the hydrological evaluation recommended that Well 5 be monitored regularly to ensure that water was being drawn from lower well depths rather than higher ones. It also recommended that land usage in

9292-564: Was first used on a continuing basis to disinfect the water supply at the Belmont filter plant, Philadelphia , Pennsylvania by using a machine invented by Charles Frederick Wallace who dubbed it the Chlorinator. It was manufactured by the Wallace & Tiernan company beginning in 1913. By 1941, disinfection of U.S. drinking water by chlorine gas had largely replaced the use of chloride of lime. As

9393-466: Was highly unlikely to have been involved in the outbreak. Well 6, which records indicate was out of service beginning May 13, was similarly determined to have been unlikely to have been the source of contamination based on its location and characteristics. To the immediate south and west of Well 5 lay farmland used as a cattle-breeding operation, occupying four lots (18–21, west to east). On April 22, 2000, following heavy rainfall on April 20–21, manure from

9494-417: Was how to render the gas portable. This might be accomplished in two ways: by liquefying it, and storing it in lead-lined iron vessels, having a jet with a very fine capillary canal, and fitted with a tap or a screw cap. The tap is turned on, and the cylinder placed in the amount of water required. The chlorine bubbles out, and in ten to fifteen minutes the water is absolutely safe. This method would be of use on

9595-439: Was little regularity to which ones were tested when. Multiple Ministry of the Environment (MOE) documents dating to throughout the 1990s note that Walkerton's sampling practices were lacking. Walkerton was placed on a list of non-compliant municipalities in 1997, but removed shortly thereafter after assurances from Stan Koebel that compliance would improve. Nevertheless, a 1998 inspection verified that eight or nine samples were still

9696-497: Was not mentioned in the conversation and he was left with the impression that the illnesses presented no imminent threat to public health. Despite their conflicting memories of the conversation, both McQuigge's and Thompson's later testimonies agreed that there had been no request issued that the mayor take action in response to the illnesses; Brockton's emergency plan was not put into action, and Thompson did not contact any public agencies to seek either information or action. Given that

9797-559: Was not running during this time period and was not tested. May 1, 2000 tests showed similar results, with Well 5 being the sole apparent contaminated water source. May 15 water testing on the Highway 9 water main construction project in Walkerton returned positive results for fecal coliform and E. coli . Due to inaccurate labelling of the samples' sources by PUC personnel, it was unclear to the testing laboratory which water samples had come from Walkerton's raw water versus its treated water, or which water had come from which well source; however,

9898-423: Was the source of the contamination; Patterson asked Earl to obtain further information and records from Stan Koebel, the PUC manager. Koebel, in his verbal interview with Earl, failed again to provide information about adverse water testing results and other potentially crucial system information; he informed Earl that Well 7 has had a new chlorinator installed, for example, but omitted mention that this had been after

9999-499: Was then turned off at 1:15 a.m. on May 21. Chief Justice of Ontario Dennis O'Connor 's later report on the event concluded that by May 19, Koebel was aware that the May 15 testing of water in the Walkerton system had returned results that indicated contamination, and his action to flush the system with heavily chlorinated water from Well 7 on May 19 was taken in the hopes of eradicating the contamination before further tests could be conducted. Significantly, Koebel did not disclose to

10100-445: Was turned off between March 10 and May 2, ran alone from May 2 through May 9 before turning off again, and was then used again between May 15 and May 19. From May 9 to May 13, Well 5 provided the bulk of Walkerton's water, supplemented from May 10–13 by Well 6. Though Well 7 ran without chlorination between May 3 and May 9, expert evaluation of well 7's pumping schedule and lack of physical vulnerabilities to contamination concluded that it

10201-411: Was unable to get in contact with anyone empowered to handle issues in Walkerton; hoping to speed up government response time, he phoned the SAC again to report his knowledge that the Walkerton PUC was using an "unlicensed operator". SAC employees, in response to this information, contacted the Walkerton PUC the same day for information on possible adverse water testing results. Stan Koebel acknowledged to

#642357