Protocol for the Issuance of a Boil Water and a Drinking Water Advisory

Transcription

1 Protocol for the Issuance of a Boil Water and A Drinking Water Advisory Protocol for the Issuance of a Boil Water and a Drinking Water Advisory I Introduction Ontario Regulation 459/00 (Drinking Water Protection) under the Ontario Water Resources Act came into effect on August 26, Ontario Regulation 459 (OR 459) requires that owners of water treatment plants of distribution systems that supply more than 50,000 litres of water on at least 88 days in every 90-day period and are capable of supplying more 250,000 litres per day or alternatively serve more than five private residences (section 3(3) of OR 459), give notice to the medical officer of health for the health unit in which the plant or system is located of the exceedences of any health-related parameter in the Ontario Drinking Water Standards. Notice must be made "if analysis of a water sample from a water distribution system or a sample of treated water is an indicator of adverse water quality described in Schedule 6" (Appendix 1) or if "a parameter exceeds the Maximum Acceptable Concentration (MAC) or Interim Maximum Acceptable Concentration (IMAC) set out for the parameter in Schedule 4 (Chemical/Physical Standards) (Appendix 2) or Schedule 5 (Radiological Standards) (Appendix 3). 1 The notice must be made verbally to someone at the health unit or if closed, with the on-call person and confirmed in writing within 24 hours. A similar notification procedure is required of laboratories. The "Protocol for the Issuance of a Boil Water and/or a Drinking Water Advisory" provides recommendations for the issuance of either a boil water advisory (BWA) or a drinking water advisory (DWA) when the risk for illness through the consumption of contaminated drinking water is a reasonable possibility. The scope of this Protocol should apply to all public/communal drinking water systems. II Issuing A Boil Water Advisory (BWA) Generally, a BWA is issued when there is: inadequate disinfection or disinfection residual in the treated water; unacceptable microbiological quality in the treated water; or epidemiological evidence (Appendix 4) that suggests drinking water is responsible for an outbreak. A BWA should be issued when there is no other reasonable alternative to protect community health. For example, a BWA should be issued if there is no other readily available source of adequate safe drinking water. Other sources include: trucking or piping in treated water from a nearby system; connecting to an improved auxiliary supply; treating water from a nearby stream or lake (which is not epidemiologically linked to the outbreak) with emergency treatment equipment and delivering it to needed sites; or using bottled water or carbonated beverages from proven safe sources. Any decision to completely close the affected distribution system until the source of the contamination is found and controlled should be weighed very carefully. This action could have negative consequences by causing back-siphonage or a lack of water (if a good alternative system is not available) for controlling fires. Spring

2 Protocol for the Issuance of a Boil Water and A Drinking Water Advisory Should a BWA be warranted, the medical officer of health (MOH) has the responsibility for the advisory and should alert the public to bring drinking water to a rolling boil for at least a minute to remove the risk of acquiring disease caused by bacteria or protozoa. The advisory should apply to all those on the suspect water distribution system and remain in effect until corrective measures have been implemented, evidence is received that microbiological parameters are met and if applicable, the outbreak declared over by the MOH. The decision to issue a boil water advisory should be made carefully. A boil water advisory may result in economic loss to food, beverage, tourism, and water recreational industries in the affected area. Burn injuries from contact with boiled drinking water may also occur. It is therefore vital to ensure that the public, affected clients, and the local media are informed with ongoing, up-to-date information on the reason for the advisory, status of the outbreak (if applicable), investigative efforts, and corrective measures (see "Communication Plan VI"). II A. Recommended Corrective Action and Issuance of BWA for Schedule 6 Microbiological Requirements in OR 459 Requirement 1 "Escherichia coli or fecal coliform is detected in any required sample other than a raw water sample." 1 Corrective Action "Increase the chlorine dose and flush the mains to ensure that a total chlorine residual of at least 1.0 mg/l or a free chlorine residual of 0.2 mg/l is achieved at all points in the affected part(s) of the distribution system. Resample and analyze. Corrective action should begin immediately and continue until E. coli and fecal coliforms are no longer detected in two consecutive sets or samples or as instructed by the local MOH." 1 BWA The medical officer of health should immediately issue a BWA upon notice and confirm with the owner/operator of the water treatment or distribution system that corrective action is being implemented. The confirmed presence of E. coli in drinking water should trigger an immediate boil water advisory. 2 The MOH should request assistance from the regional Ministry of the Environment (MOE) office where the corrective action is not resulting in two consecutive samples free of E. coli or fecal coliforms. MOE involvement may warrant an investigation to identify the source of the contamination (Appendix 5). The BWA should not be released until the MOH is satisfied that the drinking water is microbiologically safe for consumption. Normally two consecutive samples free of E. coli or fecal coliforms would be sufficient, however additional sampling and analysis may be required. Re-Sampling Re-sampling should consist of a minimum of three samples to be collected for each positive sampling site: one sample should be collected at the affected site; one at an adjacent location on the same distribution line; and a third sample should be collected some distance upstream on a feeder line toward the water source. The chlorine residual and the time of sampling for each site 2 Spring 2001

3 Protocol for the Issuance of a Boil Water and a Drinking Water Advisory should also be noted at each sampling location. The collection of three samples is considered the minimum number for each positive sampling site. The measurement of the chlorine residual in the vicinity of the positive sampling site may assist in determining the extent of the contamination within the distribution system. 1 Requirement 2 "Total coliforms detected (but not E. coli or other fecal coliforms) in any required sample other than a raw water sample." 1 Corrective Action "Re-sample at the same site and analyze. If confirmed to be positive, increase the chlorine dosage and flush the mains to ensure a total chlorine residual of at lease 1.0 mg/l or a free chlorine residual of 0.2 mg/l is achieved at all points in the affected part(s) of the distribution system. Corrective action outlined should begin immediately and continue until total coliforms are no longer detected in two consecutive sets of samples or as instructed by the local MOH." 1 BWA As total coliforms are ubiquitous in nature, their presence in the distribution system does not necessarily indicate a health risk. Nevertheless, if remedial measures, such as flushing water mains and increasing chlorine residuals do not correct the problem, then a BWA should be considered after consultation with the owner/operator of the water treatment or distribution system and the MOE regional office. If the criteria listed in items 1, 2 and 3 in the re-sampling section below are not met, then a BWA should be issued. The BWA should not be released until the MOH is satisfied that the drinking water is microbiologically safe for consumption. Normally, meeting the criteria listed in items 1, 2 and 3 below would be sufficient, however additional sampling and analysis may be required. Re-Sampling Re-sampling should consist of a minimum of three to four samples to be collected for each positive sampling site: one sample should be collected at the affected site; one at an adjacent location on the same distribution line; and a third sample should be collected some distance upstream on a feeder line toward the water source. At least 10 samples should be submitted on re-sampling. The chlorine residual and the time of sampling for each site should also be noted at each sampling location. The collection of three to four samples is considered the minimum number for each positive sampling site. The measurement of the chlorine residual in the vicinity of the positive sampling site may assist in determining the extent of the contamination within the distribution system. On re-sampling, the following results should be obtained: 1. No sample should contain more than 10 total coliform organisms per 100 ml, none of which should be faecal coliforms; and 2. No consecutive sample from the same site should show the presence of coliform organisms; and Spring

4 Protocol for the Issuance of a Boil Water and A Drinking Water Advisory 3. For community drinking water distribution systems: a) not more than one sample from a set of samples taken from the community on a given day should show the presence of coliform organisms; and b) not more than 10% of the samples based on a minimum of 10 samples should show the presence of coliform organisms. 3 Requirement 3 "Unchlorinated water is directed to the distribution system, where chlorination is used or required. This includes water in the distribution system that has less then 0.05 mg/l of free chlorine when tested." 1 Corrective Action "Restore chlorination immediately and follow the instructions as directed by the local MOH." 1 BWA The MOH should issue a BWA and maintain the advisory until two consecutive samples indicate a free chlorine residual of 0.2 mg/l or more or a total chlorine residual of at least 1.0 mg/l throughout the distribution system. MOE should be requested to provide assistance where the inability to restore a satisfactory free chlorine residual is of a technical nature. Re-Sampling Re-sampling should consist of a minimum of three to four samples to be collected for each positive sampling site: one sample should be collected at the affected site; one at an adjacent location on the same distribution line; and a third sample should be collected some distance upstream on a feeder line toward the water source. At least 10 samples should be submitted on re-sampling. The chlorine residual and the time of sampling for each site should also be noted at each sampling location. The collection of three to four samples is considered the minimum number for each positive sampling site. The measurement of the chlorine residual in the vicinity of the positive sampling site may assist in determining the extent of the contamination within the distribution system. Requirement 4 "Samples other than raw water samples, containing more than 500 colonies per ml on a heterotrophic plate count analysis." 1 The total bacterial population in a municipal distribution system is affected by the level of available nutrients and other organic matter, the age and condition of the distribution system and by the amount of chlorine residual in the water. High levels of heterotrophic bacteria in the water of a municipal distribution system are indicative of poor water quality. Such high bacterial levels contribute to taste and odour problems, enhance conditions which cause biological fouling and the persistence of pathogens, create difficulties in maintaining an adequate chlorine residual, particularly at the outer extremities of the distribution system and may actually interfere with the recovery of coliforms using the membrane filtration technique. 4 4 Spring 2001

5 Protocol for the Issuance of a Boil Water and a Drinking Water Advisory A sudden rise of an HPC or background count that has been traditionally low should give rise to concern even in the absence of a concomitant rise in the coliform count. The is particularly relevant in situations in which elevated concentrations of the general bacteria population hinder the recovery of coliforms and prevent the detection of a threat to public health. 3 Corrective Action "Re-sample and analyze. On confirmation, call the local MOH again and consult." If positive a second time, increase the chlorine dosage and flush the mains to ensure a total chlorine residual of at least 1.0 mg/l or a free chlorine residual of 0.2 mg/l is achieved at all points of the distribution system." 1 BWA If remedial measures, such as flushing water mains and increasing chlorine residuals do not correct the problem, then a BWA should be considered after consultation with the owner/operator of the water treatment or distribution system and the MOE regional office. The MOH must issue a BWA if there is widespread occurrence of 500 colonies per ml of a heterotrophic plate count analysis across the distribution system and if the results are corroborated with an unacceptable total coliform level (see Requirement 2). If the presence of heterotrophic bacteria in excess of 500 colonies per ml in the distribution system is localized and re-sampling indicates that neighbouring samples are negative, then corrective measures should be repeated and a BWA considered for consumers of the affected part of the distribution system util at least two consecutive negative test results are received. Re-Sampling Re-sampling should consist of a minimum of three to four samples to be collected for each positive sampling site: one sample should be collected at the affected site; one at an adjacent location on the same distribution line; and a third sample should be collected some distance upstream on a feeder line toward the water source. The chlorine residual and the time of sampling for each site should also be noted at each sampling location. The collection of three to four samples is considered the minimum number for each positive sampling site. The measurement of the chlorine residual in the vicinity of the positive sampling site may assist in determining the extent of the contamination within the distribution system. Requirement 5 "Samples other than raw water samples, containing more than 200 background colonies on a total coliform membrane filter analysis 1 (200 background colonies per 150 ml). Background colonies exclude gram positive bacteria. Spring

6 Protocol for the Issuance of a Boil Water and A Drinking Water Advisory Corrective Action "Re-sample and analyze. On confirmation, call the MOH and consult. If positive a second time, increase the chlorine dosage and flush the mains to ensure a total chlorine residual of at least 1.0 mg/l or a free chlorine residual of at least 0.2 mg/l is achieved at all points of the distribution system." 1 BWA As background bacteria are ubiquitous in nature, their presence in the distribution system does not necessarily indicate a health risk. Nevertheless, if remedial measures, such as flushing water mains and increasing chlorine residuals do not correct the problem, then a BWA should be considered after consultation with the owner/operator of the water treatment or distribution system and the MOE regional office. The MOH must issue a BWA if there is widespread occurrence of background coliform counts exceeding 200 colonies per ml. across the distribution system and if the results are corroborated with an unacceptable total coliform level (see Requirement 2). If the presence of background bacteria exceeding 200 colonies per 100 ml. in the distribution is localized and re-sampling indicates that neighbouring samples are negative, then corrective measures should be repeated and a BWA considered for consumers of the affected part of the distribution system until at least two consecutive negative test results are received. Re-Sampling Re-sampling should consist of a minimum of three to four samples to be collected for each positive sampling site: one sample should be collected at the affected site; one at an adjacent location on the same distribution line; and a third sample should be collected some distance upstream on a feeder line toward the water source. The chlorine residual and the time of sampling for each site should also be noted at each sampling location. The collection of three to four samples is considered the minimum number for each positive sampling site. The measurement of the chlorine residual in the vicinity of the positive sampling site may assist in determining the extent of the contamination within the distribution system. Requirement 6 "Aeromonas spp. Pseudomonas aeruginosa, Staphylococcus aureus, Clostridium spp. or fecal streptococci (Group D streptococci) are detected in samples, other than raw water samples." 1 Corrective Action "Re-sample and analyze. On confirmation, call the local MOH again and consult." 1 If positive a second time, increase the chlorine dosage and flush the mains to ensure a total chlorine residual of at least 1.0 mg/l or a free chlorine residual of 0.2 mg/l is achieved at all points of the distribution system." 6 Spring 2001

7 Protocol for the Issuance of a Boil Water and a Drinking Water Advisory BWA If remedial measures, such as flushing water main and increasing chlorine residuals do not correct the problem, then a BWA should be considered after consultation with the owner/operator of the water treatment or distribution system and the MOE regional office. The MOH should issue a BWA if there is widespread occurrence of Pseudomonas aeruginosa, Staphylococcus aureus, Clostridium spp. or fecal streptococci (Group D streptococci) across the distribution system. Their presence in the distribution system may indicate a health risk. If the presence of the above bacteria in the distribution are localized and re-sampling indicates that neighbouring samples are negative, then corrective measures should be repeated and a BWA should be considered for those consumers of the affected part of the distribution system until at least two consecutive negative test results are received. Re-Sampling Re-sampling should consist of a minimum of three to four samples to be collected for each positive sampling site: one sample should be collected at the affected site; one at an adjacent location on the same distribution line; and a third sample should be collected some distance upstream on a feeder line toward the water source. The chlorine residual and the time of sampling for each site should also be noted at each sampling location. The collection of three to four samples is considered the minimum number for each positive sampling site. The measurement of the chlorine residual in the vicinity of the positive sampling site may assist in determining the extent of the contamination within the distribution system. II B. Issuance of a BWA for Exceedence of Turbidity Requirements The maximum acceptable concentration for turbidity in drinking water is 1.0 Nephelometric Turbidity Unit (NTU) for water entering the distribution system but much lower turbidity around or less than 0.1 are commonly continuously attained in well operated treatment plants. Turbidity measurements are made frequently to confirm the existence of good operating conditions at all surface water treatment plants and at some ground water plants. An appearance related aesthetic objective of 5 NTU has been set for water taken at consumers taps. Turbidity higher than 5 NTU taken at consumer taps generally indicates severe local corrosion and/or poor bacteriological control due to loss of chlorine residual. Turbidity in water is caused by the presence of suspended tiny particles that scatter light and made the water appear cloudy. These particles are made from matter such as clay, colt, spores, plankton and other microorganisms. The most important health related effect of turbidity is interference with disinfection and with the maintenance of a chlorine residual. Viable coliform bacteria have been detected in waters with turbidity higher than 3.8 NTU even in the presence of free chlorine residuals of up to 0.5 mg/l and after contact time in excess of 30 minutes. Outbreaks of disease traced to chlorinated water supplies have been associated with high turbidity. 5 Certain water supplies, suchas groundwater, may contain non-organic-based turbidity, which may not seriously hinder disinfection. Therefore a less stringent value for turbidity in water entering a Spring

8 Protocol for the Issuance of a Boil Water and A Drinking Water Advisory distribution system may be permitted if it is demonstrated that the system has a history of acceptable microbiological quality and that a higher turbidity value will not compromise disinfection. 2 Corrective Action Deviations in turbidity would be handled by use of the plants procedures of filtering-to-waste or putting the plant offline until the problem is rectified. Plant finished water should not exceed 1.0 NTU as indicated in Schedule 4 of Ontario Regulation 459. BWA If the plant cannot be taken offline and the NTU exceeds 1.0 for a few hours or more, than a boil water advisory should be considered. If the NTU of the treated water exceeds 1.0 for 12 hours or more, then a BWA should be issued. Note that localized high turbidities in the distribution system in dead ends, mainbreaks or crossconnection situations, while the remainder of the system is normal, are managed by flushing until a total chlorine residual of at least 1.0 mg/l or a free chlorine residual of at least 0.2 mg/l is achieved and the NTU level does not exceed 1.0. Surrounding sites should be monitored to ensure that water quality is normal. In these instances, a BWA is likely not warranted. 6 II C. Issuance of BWA when Evidence Suggests a Water System-Related Outbreak BWA A BWA should be issued immediately when there is evidence that a waterborne outbreak is possibly associated with the consumption of water from a communal system (see Appendix 4). II C. 1. Confirm the Existence of the Outbreak Initial Outbreak Recognition An outbreak can be defined as a greater than expected number of persons epidemiologically linked who have the same clinical features in which there is an agent, time, place or person association. Completion of a line listing should assist in outbreak determination. Based on the experiences of other water system-related outbreaks, an outbreak should be considered when: there is a marked increase in reported cases over a short period of time, especially if this occurs at time of winter thaw/spring run-off; there is an increase in community reports of acute gastrointestinal illness, especially where the geographic area is widespread and conforms to a municipal/communal water system distribution; and consumption of municipal water is the predominant common factor with the cases. 8 Spring 2001

9 Protocol for the Issuance of a Boil Water and a Drinking Water Advisory If the above conditions are met, a water system-related outbreak should be strongly suspected, and a series of measures quickly put into place to: confirm the existence of the outbreak; determine the possible sources of the outbreak; institute appropriate control measures; and monitor the effectiveness of control measures to assure termination of the outbreak and prevention of future outbreaks. Waterborne illnesses transmitted by a communal water supply usually affect all persons irrespective of age or sex throughout the community. Common factors such as sharing the same sex/age/ethnic group, occupation, social group or religion may indicate a special event or activity. Sometimes an exceptional circumstance will provide information to the source. An example is a high incidence of illness among members of a visiting hockey team who consumed water during the period under investigation with no evidence of similar illness in their community. Illness of the immunocompromised and elderly in an area served by a common water distribution system, may also be indicative of an outbreak. If the outbreak is foodborne and not waterborne, it is probable that the cases could not be explained in terms of a common water distribution system because the cases would not be restricted to households served by the one water system. A commercially sold food source would more likely have a sporadic or geographically diverse distribution. However, it should be acknowledged that water can contaminate food during washing and it can contaminate utensils and containers used to handle or store food. Therefore, water should not be ruled out even if a food source is initially suspected. Further information on confirming the existence of a water-borne disease outbreak is found in Appendix 6. II C. 2. Determine Possible Sources of Outbreak Contaminated Water Supply Investigation Mobilize the Waterborne Disease Outbreak Team (see page 16 and 17 of the "Guideline for the Investigation and Control of Cryptosporidiosis and Giardia Waterborne Outbreaks, Program ) and contact appropriate authorities to assist with the investigation of the likely source of the waterborne outbreak. The investigation should focus on factors related to contamination not quality and aesthetics. Appendix 5, adapted from the "Procedures to Investigate Waterborne Illness, 1996, International Association of Milk, Food and Environmental Sanitarians, Inc." is a guide to the water sources and contributory factors for contamination, survival, growth or amplification of the agent which should be considered during the investigation of a suspect/confirmed contaminated municipal water supply (see insert with the "Guideline for the Investigation and Control of Cryptosporidiosis and Giardia Waterborne Outbreaks"). As applicable, an on-site investigation of source, treatment facilities, distribution lines and cross connections, should be done. Such an epidemiologically focused investigation is quite different from sanitary surveys done during routine inspections. If significant matters relating to water quality are observed, do not investigate those issues but concentrate on epidemiologically linked factors. Spring

10 Protocol for the Issuance of a Boil Water and A Drinking Water Advisory Geographic Mapping of Cases A spot map that shows the location of residence of each case may help to support a waterborne spread hypothesis when compared to a geographic overlay of a communal water distribution system. If the cases are marked by a different colour or symbol by onset week or other interval, the contamination might be explained in terms of where it was likely introduced as the initial cluster of cases would be expected to occur at or near that site. Case-Control Studies A questionnaire should be developed to ensure the evaluation of the relative contributions of potential sources of exposure. However, the ability to interview laboratory-confirmed cases and matched controls within a reasonable period of time before recall bias becomes an important factor, may be difficult. Therefore investigators should try to enroll recent cases and controls in the study. Casecontrol studies could be broadened to take into account neighbouring locations where drinking water is obtained from wells, surface water and municipal systems. However, the study should account for cases who may live in one area but work in another where exposure may vary. Review of Suspect Sources of Transmission A review of suspected sources of transmission that have been generated by the interviews of laboratory-confirmed cases may be useful as this may be the only data that can be analyzed with a smaller water system-related outbreak. The number of cases may be too small for evident geographic patterns to arise. There may be insufficient cases for, or inadequate resources to undertake a casecontrol study. Laboratory analyses of drinking water may be too late or technically inadequate to confirm the presence of the pathogen in treated water. Laboratory Verification of Water Samples All requests to a public health laboratory for analysis in water must be authorized by the local medical officer of health. For investigations within the Greater Toronto Area (GTA), the local medical officer of health will contact the Head, Enterics and Environmental Microbiology and Special Procedures in the Central Public Health Laboratory (CPHL) in Toronto directly, once the criteria have been established to justify the request. For investigations outside the GTA, the local medical officer of health will co-ordinate the investigation through the Director of the local Regional Public Health Laboratory. If sufficient evidence can be provided to support the request, the CPHL or the Regional Public Health Laboratory will make appropriate logistical arrangements with the local health unit for the collection and analysis of samples from the water source. It should be emphasized that environmental sampling is useful for epidemiological support rather than as a diagnostic tool. II C.3. Control of Cryptosporidium and Giardia Waterborne Outbreaks Information for the investigation, control and prevention of waterborne protozoan outbreaks is described in the Protocol for the Investigation and Control of Cryptosporidium and Giardia Waterborne Outbreaks, Safe Water Program, Ontario Ministry of Health and Long-Term Care, May Spring 2001

11 Protocol for the Issuance of a Boil Water and a Drinking Water Advisory III Public Health Measures Subsequent to BWA Issuance Food Premises Measures While the boil-water advisory is in effect, operators or owners of food premises must be advised to provide safe drinking water to patrons (bottled water from a reliable source or drinking water boiled for at least one minute). Local offices of the Ontario Ministry of Agriculture, Food and Rural Affairs and of the Canadian Food Inspection Agency should be advised of the BWA in order that the owners and operators of primary food processing plants take appropriate action to ensure that potable water is being used. All food requiring washing or spraying with water must be prepared with safe water. Ice, drink mixes and other food not subject to heating must be made with safe water. All soft drink beverage lines connected to tap water for mixing must be disconnected and bottled/canned beverages used. Commercial dishwashers must use a hot water cycle at 64.2? C or above. Symptomatic staff must be excluded from work for the duration of their illness (see Appendix 7). Should there be non-compliance to the advisory, a boil water order must be issued immediately under section 13 of the Health Protection and Promotion Act. Public Pool Measures During a waterborne outbreak or boil water advisory, concerns may arise with the operation of pools/spas. Before public health measures are implemented, certain exposure and operational factors need to be assessed; namely: the likelihood of contamination of the pool/spa water by incoming make-up water from the municipal/communal distribution system; the probability that infectious cases in the community may foul the pool/spa during continued operation; the risk of acquiring infection from swimming or bathing in the facility. Factors which may affect the risk include type of pool/spa filtration used (diatomaceous earth filters are considered efficient for cyst removal), and water turnover rate; and the need to empty the pool/spa and clean the facility. Decisions will need to be made for each pool/spa facility based on the individual circumstances. Suggested guidelines for distribution to pool/spa operators provided in Appendix 8. Health Care Institution and Day Care Facility Measures Appendix 9 and Infection Control Guidelines for Isolation and Precaution Techniques, revised 1990 (pages 28 and 32), Health Services and Promotion Branch and the Health Protection Branch, Health Canada can be referenced. Dental Office Measures Spring

12 Protocol for the Issuance of a Boil Water and A Drinking Water Advisory Dentists, in areas where a boil-water advisory is in effect, should be contacted and advised to use boiled or bottled water for patients to drink or rinse and for all hand washing. It is also recommended that the high/low speed turbines run dry and a hand syringe of boiled water or sterile saline be used for cooling/rinsing the tooth and/or oral tissues. Regular hand piece maintenance i.e., oiling and sterilizing, should continue per the manufacturer s instructions. To avoid any potential risk of contamination from the water supply that could occur from and during inadvertent use dental equipment with contaminated water during the advisory, dentists are advised to turn off the water supply to their dental units and sinks. If this is not possible, covering or taping the controls or outlets may be indicated e.g., triplex syringe, water dispenser, cavitron etc. IV Issuing a Boil Water Order A Boil Water Order may be made by a medical officer of health or a public health inspector under section 13 of the Health Protection and Promotion Act where the requirements of the Act are met. A section 13 Order deals generally with a health hazard, a term broadly defined under the Act. An Order under section 13 may be directed to a person who owns or is the occupier of any premises, for example, an owner of a restaurant, or to a person who is engaged in, or administers an enterprise or activity in the health unit served by the medical officer of health or the public health inspector. A boil water Order under section 13 may be made where, in the opinion of the medical officer of health or public health inspector, on reasonable grounds, a health hazard exists and the requirements in the Order are necessary to decrease the effect of the health hazard. Terms within a boil water Order may include the closing or placarding of premises, the doing of specified work, or the cleaning or disinfecting of the premises or anything else specified in the Order. Reasons for the Order must be set out. If putting the Order in writing will or is likely to substantially increase the hazard to the health of any person, the medical officer of health or the public health inspector may make an oral Order. Any person who fails to obey an Order under the Health Protection and Promotion Act is guilty of an offence and is liable on conviction to a maximum fine of $5, for every day or part of a day on which the offence occurs or continues. If a corporation is convicted of breaching an Order under the Act, the maximum penalty is $25, for every day on which the offence occurs or continues. V Lifting of Boil Water Advisory The criteria for the lifting of an advisory by the core team decision makers should be considered at the earliest possible time. The assessment should include: correction of the water treatment plant deficiency (if applicable) evidence that source water quality indicators such as Escherichia coli, and turbidity and pathogen levels have returned to baseline or acceptable levels; evidence in treated water that coliform, E. coli and turbidity levels have returned to baseline and are within regulatory limits. Successive pathogen monitoring shows results below the level of concern; action taken by the water distribution system operator to ensure that any contamination of the biofilm in the water system has been reduced (i.e. flushing lines); and 12 Spring 2001

13 Protocol for the Issuance of a Boil Water and a Drinking Water Advisory epidemiologic evidence that incidence related to consumption of water from the confirmed (suspect) distribution system has ceased for at least two incubation periods from the last related case. However the possible confounding effect of boiling water in lowering the risk of exposure during the advisory, should be taken into account. The decision to remove an advisory is the responsibility of the local medical officer of health, taking into account guidance and advice from the affected public utilities operator and other members of the Outbreak Management Team (see page 16 and 17 of the "Guideline for the Investigation and Control of Cryptosporidium and Giardia Waterborne Outbreaks,"). Disagreement between agencies to remove boil water advice should not occur often but if it does then the final decision is with the medical officer of health. VI Issuing a Drinking Water Advisory (DWA) The medical officer of health should issue a DWA whenever there is reason to believe that a condition exists with a drinking water supply that may result in a risk to consumers that cannot be corrected by boiling the water or by disinfection. This condition may arise for the following reasons: a MAC of a chemical/physical standard, is exceeded (see Appendix 2 "Schedule 4" of Ontario Regulation 459 (Drinking Water Protection)); a MAC of a radiological standard is exceeded (see Appendix 3 "Schedule 5 of Ontario Regulation 459 (Drinking Water Protection)); and other condition, judged to be hazardous than cannot be rectified by boiling water. VI A. Recommended Corrective Action and Issuance of a DWA for Schedule 6 Non-Microbiological Requirements in OR 459 (Drinking Water Protection) Requirement 7 "Sodium concentration exceeds 20 mg/l. Notification need not occur more frequently than once in five years." Corrective Action "Re-sample and analyze. On confirmation, calls the local MOH again. The aesthetic objective of sodium in drinking water is 200 mg/l. The local MOH must be notified when the sodium concentration exceeds 20 mg/l so that this information may be communicated to local physicians for their use with patients on sodium restricted diets." DWA The medical officer of health should issue a DWA upon notice and ensure that all physicians within the area affected by the distribution system are advised. Recommendations should be made to use alternate sources of water e.g., bottled water until test results indicate that sodium concentration levels fall below 20 mg/l. Spring

14 Protocol for the Issuance of a Boil Water and A Drinking Water Advisory Requirement 8 "A pesticide not listed in Table D of Schedule 2 is detected" (Appendix 11). Corrective Action "Resample and analyze. On confirmation, call the local MOH again and consult. Drinking water should be free of pesticides and every effort should be made to prevent pesticides entering raw water sources. Pesticides may be reported by their most common trade name, a listing of which, called the compendium of Scheduled Pesticides is accessible on the internet through the web site of the Ministry of the Environment at: DWA The medical officer of health, should immediately issue a DWA upon notice that remains in effect until the pesticide(s) are not detected in the drinking water or until after consultation with MOE it is determined that their presence is no longer considered a health hazard. A recommendation shall be made in the advisory to consume water from an alternate source e.g., bottled water, other municipal supply etc. until declared safe to drink. Contact should be made with MOE in order that results of their investigation and progress of remedial action be shared. VI B. Issuance of a DWA for Exceedence of a MAC or IMAC Parameter in Schedule 4 (Chemical/Physical Standards) of OR 459. The medical officer of health should immediately issue a DWA upon notice of the exceedence of the MAC or IMAC of a physical or chemical parameter listed in Schedule 4 of OR 459 (Appendix 2). The DWA shall remain in effect until there is no longer an exceedence of the MAC or IMAC detected Corrective Action Re-sample and analyze. On confirmation, call the local MOH again and consult. Drinking water should not exceed the MACs or IMACs of the physical or chemical parameters listed in Schedule 4 of OR 459. Every effort should be made to prevent these chemicals from entering raw water sources. DWA The medical officer of health should immediately issue a DWA upon notice that remains in effect until the chemicals or physical substances do not exceed their MAC or IMAC. VI C. Issuance of a DWA for Exceedence of a MAC Parameter in Schedule 5 (Radiological Standards) of OR Spring 2001

15 Protocol for the Issuance of a Boil Water and a Drinking Water Advisory The medical officer of health should immediately issue a DWA upon notice of the exceedence of a MAC of a radiological parameter listed in Schedule 5 of OR 459 (Appendix 3). The DWA shall be in effect until an exceedence of the MAC or IMAC is no longer detected Corrective Action Re-sample and analyze. On confirmation, call the local MOH again and consult. Drinking water should not exceed the MACs or IMACs of the radiological parameters listed in Schedule 5 of OR 459. Every effort should be made to prevent these radiological substances from entering raw water sources. DWA The medical officer of health should immediately issue a DWA upon notice that remains in effect until the radiological parameters do not exceed their MAC or IMAC. VII Ministry of Health and Long-Term Care (MOHLTC) Notification The MOHLTC must be advised of the BWA, Boil Water Order or DWA within 24 hours of issuance pursuant to section 86.2 of the Health Protection and Promotion Act. The provision of the information is facilitated through the completion and faxing of the "Notification of Drinking Water Advisory to Public Health Branch" form (see Appendix 10). VIII Communication Plan A communication plan should be developed before a boil water advisory or a drinking water advisory is issued. Many health departments already have a communication policy. If a policy is not yet in place, basic points to include in a communication plan may include: target groups or specific audiences to be contacted e.g., foodservice owners/operators, owner/operator of water treatment plant, Ministry of Environment, Canadian Food Inspection Agency and Ministry of Agriculture, Food, and Rural Affairs District Offices; key messages for the general public and specific audiences (appendices 12 and 13); designated health department spokesperson(s); contact information for media distribution list e.g., names, telephone/fax numbers, news deadlines); contact information for spokespersons of other relevant agencies; and timetable for information releases each day. Basic Questions to be Addressed by Communications Some common questions to address communications are: What is the reason for the boil or drinking water advisory? Spring

16 Protocol for the Issuance of a Boil Water and A Drinking Water Advisory What can the individual do (e.g., boil water) or what other drinking water alternative sources are available? Is there an information hotline and how can it be accessed (telephone number, hours of operation)? How long will the advisory remain in effect? If the advisory is related to illness: What is (definition)? What are the symptoms? How does the illness spread? What is the public health department doing (and other agencies if it is a joint release)? What special precautions should at-risk populations take (immunocompromised)? Communication Strategy If possible, the spokespersons of the agencies involved with the advisory should work together to issue joint communications. This ensures that everyone is giving out the same message and demonstrates a co-operative effort. If joint communications are not possible, there should still be sharing of messages prior to release to ensure accuracy, agreement and consistency of information. Health department staff should be kept informed of all information that has been released. Staff should know the designated spokesperson to whom inquiries are directed. It is recommended that the BWA or DWA be distributed through any or all of the following means in those areas affected by the advisory: local radio and television; local newspapers; posting in publicly frequented sites e.g., supermarket and community centre notice boards; door-to-door delivery to households serviced by the affected distribution system; public schools; and utility bill envelope inserts. The postings, door-to-door deliveries and utility bill insertions should be a co-ordinated action by those best able to effectively accomplish the task of early notification. The health unit would direct the local public utility to insert the BWA or DWA in the regular billings and the municipality to carry out door-to-door delivery. 16 Spring 2001

17 Protocol for the Issuance of a Boil Water and a Drinking Water Advisory References 1. Regulation Made Under the Ontario Water Resources Act (Ontario Regulation 459/00). Ontario Ministry of the Environment. 2. Guidelines for Canadian Drinking Water Quality, Sixth Edition, Health Canada. 3. Guidelines for Canadian Drinking Water Quality - Supporting Documents, Microbiological Parameters: Bacteriological Quality, Health Canada. 4. Recommendations of the Technical Advisory Committee on Environmental Microbiology, Laboratory Services Branch, January 1, Ontario Ministry of Health and Long-Term Care. 5. Ontario Drinking Water Standards, August Ontario Ministry of the Environment. 6. Boil Water Notice Guidelines, 2000 for the EPCOR Water System, Edmonton, Alberta. Spring

18 Protocol for the Issuance of a Boil Water and A Drinking Water Advisory 18 Spring 2001

19 Protocol for the Issuance of a Boil Water and a Drinking Water Advisory APPENDICES 1. Schedule 6 of Ontario Regulation 459 (Drinking Water Protection) - Indicators of Adverse Water Quality 2. Schedule 4 of Ontario Regulation 459 (Drinking Water Protection) - Chemical/Physical Standards 3. Schedule 5 of Ontario Regulation 459 (Drinking Water Protection) - Radiological Standards 4. Strength of Association Between Illness and Water 5. Source of Contaminated Water 6. Confirmation of a Water-borne Disease Outbreak 7. Guidelines for Food Establishment Operators During a Boil Water Advisory 8. Guideline for Public Pool/Spa Operators 9. Guideline for Health Care Institution Infection and Day Care Facilities Staff during a Boil Water Advisory 10. Notification of Drinking Water Advisory to Public Health Branch 11. Table D - Pesticides and PCB 12. Boil Water Advisory 13. Health Facts - How to use water safely during a "boil water advisory" Spring

20 Protocol for the Issuance of a Boil Water and A Drinking Water Advisory 20 Spring 2001

21 Protocol for the Issuance of a Boil Water and a Drinking Water Advisory Appendix 1 Schedule 6 of Ontario Regulation 459 (Drinking Water Protection) INDICATORS OF ADVERSE WATER QUALITY Each of the following is an indicator of adverse water quality: 1. Escherichia coli (E. coli) or fecal coliform is detected in any required sample other than a raw water sample. (Corrective action: Increase the chlorine dose and flush the mains to ensure that a total chlorine residual of at least 1.0 mg/l or a free chlorine residual of 0.2 mg/l is achieved at all points in the affected part(s) of the distribution system. Resample and analyze. Corrective action should begin immediately and continue until E. coli and fecal coliforms are no longer detected in two consecutive sets of samples or as instructed by the local medical officer of health.) 2. Total coliforms detected but not Escherichia coli or other fecal coliforms) in any required sample other than a raw water sample. (Corrective action: Re-sample at the same site and analyze. If confirmed to be positive, increase the chlorine dose and flush the mains to ensure a total chlorine residual of at least 1.0 mg/l or a free chlorine residual of 0.2 mg/l to all points in the affected part(s) of the distribution system. Corrective action outlined should begin immediately and continue until total coliforms are no longer detected in two consecutive sets of samples or as instructed by the local medical officer of health.) 3. Unchlorinated water is directed to the distribution system, where chlorination is used or required. This includes water in the distribution system which has less than 0.05 mg/l of free chlorine residual when tested. (Corrective action: Restore chlorination immediately and follow instructions as directed by the local medical officer of health.) 4. Samples, other than raw water samples, containing more than 500 colonies per ml on a heterotrophic plate count analysis. (Corrective action: Resample and analyze. On confirmation, call the local medical officer of health again and consult.) 5. Samples, other than raw water samples, containing more than 200 background colonies on a total coliform membrane filter analysis. (Corrective action: Resample and analyze. On confirmation, call the local medical officer of health again and consult.) 6. Aeromonas spp., Pseudomonas aeruginosa, Staphylococcus aureus, Clostridium spp. or fecal streptococci (Group D streptococci) are detected in samples, other than raw water samples. (Corrective action: Resample and analyze. On confirmation, call the local medical officer of health again and consult.) Spring

22 Protocol for the Issuance of a Boil Water and A Drinking Water Advisory 7. Sodium concentration exceeds 20 mg/l. Notification need not occur more frequently than once in five years. (Corrective action: Re-sample and analyze. On confirmation, call the local medical officer of health again. The aesthetic objective for sodium in drinking water is 200 mg/l. The local medical officer of health must be notified when the sodium concentration exceeds 20 mg/l so that this information may be communicated to local physicians for their use with patients on sodium restricted diets.) 8. A pesticide not listed in Table D of Schedule 2 is detected. (Corrective action: Re-sample, take a corresponding raw water sample and analyze. On confirmation, call the local medical officer of health again and consult. Drinking water should be free of pesticides and every effort should be made to prevent pesticides from entering raw water sources. Pesticides may be reported by their most common trade name, a listing of which, called the Compendium of Scheduled Pesticides is accessible on the internet through the web site of the Ministry of the Environment at 22 Spring 2001