Protocol for the Issuance of a Boil Water and a Drinking ... · Safe Water Program Protocol for the Issuance of a Boil Water and A Drinking Water Advisory 2 Spring 2001 Should a BWA

Protocol for the Issuance of a Boil Water and A Drinking Water Advisory Safe Water Program

Spring 2001 1

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 intoeffect on August 26, 2000. Ontario Regulation 459 (OR 459) requires that owners of water treatment plantsof distribution systems that supply more than 50,000 litres of water on at least 88 days in every 90-dayperiod and are capable of supplying more 250,000 litres per day or alternatively serve more than five privateresidences (section 3(3) of OR 459), give notice to the medical officer of health for the health unit in whichthe plant or system is located of the exceedences of any health-related parameter in the Ontario DrinkingWater Standards. Notice must be made "if analysis of a water sample from a water distribution system or asample 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 AcceptableConcentration (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 andconfirmed 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" providesrecommendations 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 reasonablepossibility. 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. Forexample, a BWA should be issued if there is no other readily available source of adequate safe drinkingwater. 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 isfound and controlled should be weighed very carefully. This action could have negative consequences bycausing back-siphonage or a lack of water (if a good alternative system is not available) for controlling fires.

Safe Water Program Protocol for the Issuance of a Boil Water and A Drinking Water Advisory

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Should a BWA be warranted, the medical officer of health (MOH) has the responsibility for the advisory andshould alert the public to bring drinking water to a rolling boil for at least a minute to remove the risk ofacquiring disease caused by bacteria or protozoa. The advisory should apply to all those on the suspect waterdistribution system and remain in effect until corrective measures have been implemented, evidence isreceived 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 ineconomic loss to food, beverage, tourism, and water recreational industries in the affected area. Burninjuries 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 theadvisory, 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 MicrobiologicalRequirements in OR 459

• Requirement 1

"Escherichia coli or fecal coliform is detected in any required sample other than a raw watersample." 1

Corrective Action

"Increase the chlorine dose and flush the mains to ensure that a total chlorine residual of at least1.0 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 immediatelyand continue until E. coli and fecal coliforms are no longer detected in two consecutive sets orsamples or as instructed by the local MOH."1

BWA

The medical officer of health should immediately issue a BWA upon notice and confirm withthe owner/operator of the water treatment or distribution system that corrective action is beingimplemented. 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 theEnvironment (MOE) office where the corrective action is not resulting in two consecutivesamples free of E. coli or fecal coliforms. MOE involvement may warrant an investigation toidentify the source of the contamination (Appendix 5). The BWA should not be released untilthe 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 positivesampling site: one sample should be collected at the affected site; one at an adjacent location onthe same distribution line; and a third sample should be collected some distance upstream on afeeder line toward the water source. The chlorine residual and the time of sampling for each site

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

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should also be noted at each sampling location. The collection of three samples is consideredthe minimum number for each positive sampling site. The measurement of the chlorine residualin the vicinity of the positive sampling site may assist in determining the extent of thecontamination within the distribution system. 1

• Requirement 2

"Total coliforms detected (but not E. coli or other fecal coliforms) in any required sample other than araw water sample." 1

Corrective Action

"Re-sample at the same site and analyze. If confirmed to be positive, increase the chlorinedosage and flush the mains to ensure a total chlorine residual of at lease 1.0 mg/L or a freechlorine residual of 0.2 mg/L is achieved at all points in the affected part(s) of the distributionsystem. Corrective action outlined should begin immediately and continue until total coliformsare 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 notnecessarily indicate a health risk. Nevertheless, if remedial measures, such as flushing watermains and increasing chlorine residuals do not correct the problem, then a BWA should beconsidered after consultation with the owner/operator of the water treatment or distributionsystem and the MOE regional office. If the criteria listed in items 1, 2 and 3 in the re-samplingsection below are not met, then a BWA should be issued. The BWA should not be releaseduntil 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, howeveradditional sampling and analysis may be required.

Re-Sampling

Re-sampling should consist of a minimum of three to four samples to be collected for eachpositive sampling site: one sample should be collected at the affected site; one at an adjacentlocation on the same distribution line; and a third sample should be collected some distanceupstream on a feeder line toward the water source. At least 10 samples should be submitted onre-sampling. The chlorine residual and the time of sampling for each site should also be notedat each sampling location. The collection of three to four samples is considered the minimumnumber for each positive sampling site. The measurement of the chlorine residual in thevicinity of the positive sampling site may assist in determining the extent of the contaminationwithin 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 ofwhich should be faecal coliforms; and

2. No consecutive sample from the same site should show the presence of coliform organisms;and


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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; andb) 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 orrequired. This includes water in the distribution system that has less then 0.05 mg/L of freechlorine 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 samplesindicate a free chlorine residual of 0.2 mg/L or more or a total chlorine residual of at least 1.0mg/L throughout the distribution system. MOE should be requested to provide assistance wherethe 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 eachpositive sampling site: one sample should be collected at the affected site; one at an adjacentlocation on the same distribution line; and a third sample should be collected some distanceupstream on a feeder line toward the water source. At least 10 samples should be submitted onre-sampling. The chlorine residual and the time of sampling for each site should also be notedat each sampling location. The collection of three to four samples is considered the minimumnumber for each positive sampling site. The measurement of the chlorine residual in thevicinity of the positive sampling site may assist in determining the extent of the contaminationwithin the distribution system.

• Requirement 4

"Samples other than raw water samples, containing more than 500 colonies per mL on aheterotrophic plate count analysis." 1

“The total bacterial population in a municipal distribution system is affected by the level ofavailable nutrients and other organic matter, the age and condition of the distribution system andby the amount of chlorine residual in the water. High levels of heterotrophic bacteria in thewater of a municipal distribution system are indicative of poor water quality. Such highbacterial levels contribute to taste and odour problems, enhance conditions which causebiological fouling and the persistence of pathogens, create difficulties in maintaining anadequate chlorine residual, particularly at the outer extremities of the distribution system andmay actually interfere with the recovery of coliforms using the membrane filtration technique.”4


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“A sudden rise of an HPC or background count that has been traditionally low should give rise toconcern even in the absence of a concomitant rise in the coliform count. The is particularlyrelevant in situations in which elevated concentrations of the general bacteria population hinderthe 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 asecond time, increase the chlorine dosage and flush the mains to ensure a total chlorine residualof at least 1.0 mg/L or a free chlorine residual of 0.2 mg/L is achieved at all points of thedistribution system." 1

BWA

If remedial measures, such as flushing water mains and increasing chlorine residuals do notcorrect the problem, then a BWA should be considered after consultation with theowner/operator of the water treatment or distribution system and the MOE regional office. TheMOH must issue a BWA if there is widespread occurrence of 500 colonies per mL of aheterotrophic plate count analysis across the distribution system and if the results arecorroborated with an unacceptable total coliform level (see Requirement 2).

If the presence of heterotrophic bacteria in excess of 500 colonies per mL in the distributionsystem is localized and re-sampling indicates that neighbouring samples are negative, thencorrective measures should be repeated and a BWA considered for consumers of the affectedpart 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 eachpositive sampling site: one sample should be collected at the affected site; one at an adjacentlocation on the same distribution line; and a third sample should be collected some distanceupstream on a feeder line toward the water source. The chlorine residual and the time ofsampling for each site should also be noted at each sampling location. The collection of three tofour samples is considered the minimum number for each positive sampling site. Themeasurement of the chlorine residual in the vicinity of the positive sampling site may assist indetermining the extent of the contamination within the distribution system.

• Requirement 5

"Samples other than raw water samples, containing more than 200 background colonies on atotal coliform membrane filter analysis”1 (200 background colonies per 150 mL). Backgroundcolonies exclude gram positive bacteria.


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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 1.0mg/L or a free chlorine residual of at least 0.2 mg/L is achieved at all points of the distributionsystem." 1

BWA

As background bacteria are ubiquitous in nature, their presence in the distribution system doesnot necessarily indicate a health risk. Nevertheless, if remedial measures, such as flushing watermains and increasing chlorine residuals do not correct the problem, then a BWA should beconsidered after consultation with the owner/operator of the water treatment or distributionsystem and the MOE regional office. The MOH must issue a BWA if there is widespreadoccurrence of background coliform counts exceeding 200 colonies per mL. across thedistribution 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 islocalized and re-sampling indicates that neighbouring samples are negative, then correctivemeasures should be repeated and a BWA considered for consumers of the affected part of thedistribution system until at least two consecutive negative test results are received.

Re-Sampling


Requirement 6

"Aeromonas spp. Pseudomonas aeruginosa, Staphylococcus aureus, Clostridium spp. or fecalstreptococci (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 positivea second time, increase the chlorine dosage and flush the mains to ensure a total chlorine residualof at least 1.0 mg/L or a free chlorine residual of 0.2 mg/L is achieved at all points of thedistribution system."


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BWA

If remedial measures, such as flushing water main and increasing chlorine residuals do notcorrect the problem, then a BWA should be considered after consultation with theowner/operator of the water treatment or distribution system and the MOE regional office. TheMOH should issue a BWA if there is widespread occurrence of Pseudomonas aeruginosa,Staphylococcus aureus, Clostridium spp. or fecal streptococci (Group D streptococci) across thedistribution 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 indicatesthat neighbouring samples are negative, then corrective measures should be repeated and a BWAshould be considered for those consumers of the affected part of the distribution system until atleast two consecutive negative test results are received.

Re-Sampling


II B. Issuance of a BWA for Exceedence of Turbidity Requirements

“The maximum acceptable concentration for turbidity in drinking water is 1.0 NephelometricTurbidity Unit (NTU) for water entering the distribution system but much lower turbidity around orless than 0.1 are commonly continuously attained in well operated treatment plants. Turbiditymeasurements are made frequently to confirm the existence of good operating conditions at allsurface 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/orpoor bacteriological control due to loss of chlorine residual.

Turbidity in water is caused by the presence of suspended tiny particles that scatter light and madethe water appear cloudy. These particles are made from matter such as clay, colt, spores, planktonand other microorganisms. The most important health related effect of turbidity is interference withdisinfection and with the maintenance of a chlorine residual. Viable coliform bacteria have beendetected in waters with turbidity higher than 3.8 NTU even in the presence of free chlorine residualsof up to 0.5 mg/L and after contact time in excess of 30 minutes. Outbreaks of disease traced tochlorinated water supplies have been associated with high turbidity.”5

“Certain water supplies, such as groundwater, may contain non-organic-based turbidity, which maynot seriously hinder disinfection. Therefore a less stringent value for turbidity in water entering a


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distribution system may be permitted if it is demonstrated that the system has a history of acceptablemicrobiological 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 orputting the plant offline until the problem is rectified.

Plant finished water should not exceed 1.0 NTU as indicated in Schedule 4 of Ontario Regulation459.

BWA

If the plant cannot be taken offline and the NTU exceeds 1.0 for a few hours or more, than a boilwater advisory should be considered. If the NTU of the treated water exceeds 1.0 for 12 hours ormore, then a BWA should be issued.

Note that localized high turbidities in the distribution system in dead ends, mainbreaks or cross-connection situations, while the remainder of the system is normal, are managed by flushing until atotal chlorine residual of at least 1.0 mg/L or a free chlorine residual of at least 0.2 mg/L is achievedand the NTU level does not exceed 1.0. Surrounding sites should be monitored to ensure that waterquality 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 possiblyassociated 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 linkedwho 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 ofother 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 occursat time of winter thaw/spring run-off;

• there is an increase in community reports of acute gastrointestinal illness, especially where thegeographic area is widespread and conforms to a municipal/communal water systemdistribution; and

• consumption of municipal water is the predominant common factor with the cases.


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If the above conditions are met, a water system-related outbreak should be strongly suspected, and aseries 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 ageor 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 exceptionalcircumstance will provide information to the source. An example is a high incidence of illness amongmembers of a visiting hockey team who consumed water during the period under investigation with noevidence of similar illness in their community. Illness of the immunocompromised and elderly in an areaserved 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 termsof a common water distribution system because the cases would not be restricted to households served by theone water system. A commercially sold food source would more likely have a sporadic or geographicallydiverse distribution. However, it should be acknowledged that water can contaminate food during washingand it can contaminate utensils and containers used to handle or store food. Therefore, water should not beruled 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 theInvestigation and Control of Cryptosporidiosis and Giardia Waterborne Outbreaks, Program”) andcontact appropriate authorities to assist with the investigation of the likely source of the waterborneoutbreak. The investigation should focus on factors related to contamination not quality andaesthetics.

Appendix 5, adapted from the "Procedures to Investigate Waterborne Illness, 1996, InternationalAssociation of Milk, Food and Environmental Sanitarians, Inc." is a guide to the water sources andcontributory factors for contamination, survival, growth or amplification of the agent which should beconsidered during the investigation of a suspect/confirmed contaminated municipal water supply (seeinsert with the "Guideline for the Investigation and Control of Cryptosporidiosis and GiardiaWaterborne Outbreaks"). As applicable, an on-site investigation of source, treatment facilities,distribution lines and cross connections, should be done. Such an epidemiologically focusedinvestigation is quite different from sanitary surveys done during routine inspections. If significantmatters relating to water quality are observed, do not investigate those issues but concentrate onepidemiologically linked factors.


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• Geographic Mapping of Cases

A spot map that shows the location of residence of each case may help to support a waterbornespread 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, thecontamination might be explained in terms of where it was likely introduced as the initial cluster ofcases 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 potentialsources of exposure. However, the ability to interview laboratory-confirmed cases and matchedcontrols within a reasonable period of time before recall bias becomes an important factor, may bedifficult. Therefore investigators should try to enroll recent cases and controls in the study. Case-control studies could be broadened to take into account neighbouring locations where drinking wateris obtained from wells, surface water and municipal systems. However, the study should account forcases 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 oflaboratory-confirmed cases may be useful as this may be the only data that can be analyzed with asmaller water system-related outbreak. The number of cases may be too small for evident geographicpatterns to arise. There may be insufficient cases for, or inadequate resources to undertake a case-control study. Laboratory analyses of drinking water may be too late or technically inadequate toconfirm 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 localmedical officer of health. For investigations within the Greater Toronto Area (GTA), the localmedical officer of health will contact the Head, Enterics and Environmental Microbiology andSpecial Procedures in the Central Public Health Laboratory (CPHL) in Toronto directly, once thecriteria have been established to justify the request. For investigations outside the GTA, the localmedical officer of health will co-ordinate the investigation through the Director of the local RegionalPublic Health Laboratory. If sufficient evidence can be provided to support the request, the CPHL orthe Regional Public Health Laboratory will make appropriate logistical arrangements with the localhealth unit for the collection and analysis of samples from the water source. It should be emphasizedthat 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 inthe “Protocol for the Investigation and Control of Cryptosporidium and Giardia Waterborne Outbreaks, SafeWater Program, Ontario Ministry of Health and Long-Term Care, May 1997.


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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 toprovide safe drinking water to patrons (bottled water from a reliable source or drinking water boiledfor 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 thatthe owners and operators of primary food processing plants take appropriate action to ensure thatpotable water is being used. All food requiring washing or spraying with water must be preparedwith safe water. Ice, drink mixes and other food not subject to heating must be made with safewater. All soft drink beverage lines connected to tap water for mixing must be disconnected andbottled/canned beverages used. Commercial dishwashers must use a hot water cycle at 64.2? C orabove. Symptomatic staff must be excluded from work for the duration of their illness (seeAppendix 7). Should there be non-compliance to the advisory, a boil water order must be issuedimmediately 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 ofpools/spas. Before public health measures are implemented, certain exposure and operationalfactors need to be assessed; namely:

• the likelihood of contamination of the pool/spa water by incoming make-up water from themunicipal/communal distribution system;

• the probability that infectious cases in the community may foul the pool/spa during continuedoperation;

• the risk of acquiring infection from swimming or bathing in the facility. Factors which mayaffect the risk include type of pool/spa filtration used (diatomaceous earth filters areconsidered 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, HealthCanada can be referenced.

• Dental Office Measures


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Dentists, in areas where a boil-water advisory is in effect, should be contacted and advised to useboiled or bottled water for patients to drink or rinse and for all hand washing. It is alsorecommended that the high/low speed turbines run dry and a hand syringe of boiled water or sterilesaline 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 potentialrisk of contamination from the water supply that could occur from and during inadvertent use dentalequipment with contaminated water during the advisory, dentists are advised to turn off the watersupply to their dental units and sinks. If this is not possible, covering or taping the controls oroutlets 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 undersection 13 of the Health Protection and Promotion Act where the requirements of the Act are met. Asection 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 enterpriseor activity in the health unit served by the medical officer of health or the public health inspector. Aboil water Order under section 13 may be made where, in the opinion of the medical officer of healthor public health inspector, on reasonable grounds, a health hazard exists and the requirements in theOrder are necessary to decrease the effect of the health hazard. Terms within a boil water Order mayinclude the closing or placarding of premises, the doing of specified work, or the cleaning ordisinfecting of the premises or anything else specified in the Order. Reasons for the Order must beset out. If putting the Order in writing will or is likely to substantially increase the hazard to thehealth of any person, the medical officer of health or the public health inspector may make an oralOrder. Any person who fails to obey an Order under the Health Protection and Promotion Act isguilty of an offence and is liable on conviction to a maximum fine of $5,000.00 for every day or partof a day on which the offence occurs or continues. If a corporation is convicted of breaching anOrder under the Act, the maximum penalty is $25,000.00 for every day on which the offence occursor continues.

V Lifting of Boil Water Advisory

The criteria for the lifting of an advisory by the core team decision makers should be considered atthe 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 thelevel of concern;

• action taken by the water distribution system operator to ensure that any contamination of thebiofilm in the water system has been reduced (i.e. flushing lines); and


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• 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 lastrelated case. However the possible confounding effect of boiling water in lowering the risk ofexposure 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 othermembers of the Outbreak Management Team (see page 16 and 17 of the "Guideline for theInvestigation and Control of Cryptosporidium and Giardia Waterborne Outbreaks,"). Disagreementbetween agencies to remove boil water advice should not occur often but if it does then the finaldecision 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 acondition exists with a drinking water supply that may result in a risk to consumers that cannot becorrected by boiling the water or by disinfection. This condition may arise for the followingreasons:

• a MAC of a chemical/physical standard, is exceeded (see Appendix 2 "Schedule 4" of OntarioRegulation 459 (Drinking Water Protection));

• a MAC of a radiological standard is exceeded (see Appendix 3 "Schedule 5 of OntarioRegulation 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-MicrobiologicalRequirements in OR 459 (Drinking Water Protection)

• Requirement 7

"Sodium concentration exceeds 20 mg/L. Notification need not occur more frequently than once infive years."

Corrective Action

"Re-sample and analyze. On confirmation, calls the local MOH again. The aesthetic objective ofsodium in drinking water is 200 mg/L. The local MOH must be notified when the sodiumconcentration exceeds 20 mg/L so that this information may be communicated to local physiciansfor 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 withinthe area affected by the distribution system are advised. Recommendations should be made to usealternate sources of water e.g., bottled water until test results indicate that sodium concentrationlevels fall below 20 mg/L.


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• 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 watershould be free of pesticides and every effort should be made to prevent pesticides entering rawwater 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 ofthe Ministry of the Environment at: www.ene.gov.on.ca".

DWA

The medical officer of health, should immediately issue a DWA upon notice that remains in effectuntil the pesticide(s) are not detected in the drinking water or until after consultation with MOE it isdetermined that their presence is no longer considered a health hazard. A recommendation shall bemade in the advisory to consume water from an alternate source e.g., bottled water, other municipalsupply etc. until declared safe to drink. Contact should be made with MOE in order that results oftheir 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 ofthe MAC or IMAC of a physical or chemical parameter listed in Schedule 4 of OR 459 (Appendix2). The DWA shall remain in effect until there is no longer an exceedence of the MAC or IMACdetected

Corrective Action

Re-sample and analyze. On confirmation, call the local MOH again and consult. Drinking watershould not exceed the MACs or IMACs of the physical or chemical parameters listed in Schedule 4of OR 459. Every effort should be made to prevent these chemicals from entering raw watersources.

DWA

The medical officer of health should immediately issue a DWA upon notice that remains in effectuntil 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 (RadiologicalStandards) of OR 459.


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The medical officer of health should immediately issue a DWA upon notice of the exceedence of aMAC of a radiological parameter listed in Schedule 5 of OR 459 (Appendix 3). The DWA shall bein 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 watershould not exceed the MACs or IMACs of the radiological parameters listed in Schedule 5 of OR459. Every effort should be made to prevent these radiological substances from entering raw watersources.

DWA

The medical officer of health should immediately issue a DWA upon notice that remains in effectuntil 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 ofissuance pursuant to section 86.2 of the Health Protection and Promotion Act. The provision of theinformation is facilitated through the completion and faxing of the "Notification of Drinking WaterAdvisory 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 wateradvisory is issued. Many health departments already have a communication policy. If a policy isnot 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 InspectionAgency 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?


16 Spring 2001

• What can the individual do (e.g., boil water) or what other drinking water alternative sourcesare available?

• Is there an information hotline and how can it be accessed (telephone number, hours ofoperation)?

• 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 toissue joint communications. This ensures that everyone is giving out the same message anddemonstrates a co-operative effort. If joint communications are not possible, there should still besharing 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. Staffshould 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 meansin 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 bythose best able to effectively accomplish the task of early notification. The health unit would directthe local public utility to insert the BWA or DWA in the regular billings and the municipality tocarry out door-to-door delivery.


Spring 2001 17

References

1. Regulation Made Under the Ontario Water Resources Act (Ontario Regulation 459/00). OntarioMinistry of the Environment.

2. Guidelines for Canadian Drinking Water Quality, Sixth Edition, 1996. Health Canada.

3. Guidelines for Canadian Drinking Water Quality - Supporting Documents,www.hc-sc.ca/ehp/ehd/catalogue/bch_pubs/dwgsup_doc/dwgswp_doc.htm MicrobiologicalParameters: Bacteriological Quality, 2000. Health Canada.

4. Recommendations of the Technical Advisory Committee on Environmental Microbiology,Laboratory Services Branch, January 1, 1998. Ontario Ministry of Health and Long-Term Care.

5. Ontario Drinking Water Standards, August 2000. Ontario Ministry of the Environment.

6. Boil Water Notice Guidelines, 2000 for the EPCOR Water System, Edmonton, Alberta.


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Spring 2001 19

APPENDICES

1. Schedule 6 of Ontario Regulation 459 (Drinking Water Protection) - Indicators ofAdverse Water Quality

2. Schedule 4 of Ontario Regulation 459 (Drinking Water Protection) - Chemical/PhysicalStandards

3. Schedule 5 of Ontario Regulation 459 (Drinking Water Protection) - RadiologicalStandards

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 aBoil 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"


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Spring 2001 21

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 watersample. (Corrective action: Increase the chlorine dose and flush the mains to ensure that a totalchlorine residual of at least 1.0 mg/L or a free chlorine residual of 0.2 mg/L is achieved at all pointsin the affected part(s) of the distribution system. Resample and analyze. Corrective action shouldbegin immediately and continue until E. coli and fecal coliforms are no longer detected in twoconsecutive 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 sampleother than a raw water sample. (Corrective action: Re-sample at the same site and analyze. Ifconfirmed to be positive, increase the chlorine dose and flush the mains to ensure a total chlorineresidual 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 untiltotal coliforms are no longer detected in two consecutive sets of samples or as instructed by the localmedical 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 residualwhen tested. (Corrective action: Restore chlorination immediately and follow instructions as directedby the local medical officer of health.)

4. Samples, other than raw water samples, containing more than 500 colonies per mL on a heterotrophicplate count analysis. (Corrective action: Resample and analyze. On confirmation, call the localmedical officer of health again and consult.)

5. Samples, other than raw water samples, containing more than 200 background colonies on a totalcoliform membrane filter analysis. (Corrective action: Resample and analyze. On confirmation, callthe local medical officer of health again and consult.)

6. Aeromonas spp., Pseudomonas aeruginosa, Staphylococcus aureus, Clostridium spp. or fecalstreptococci (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 healthagain and consult.)


22 Spring 2001

7. Sodium concentration exceeds 20 mg/L. Notification need not occur more frequently than once infive years. (Corrective action: Re-sample and analyze. On confirmation, call the local medicalofficer of health again. The aesthetic objective for sodium in drinking water is 200 mg/L. The localmedical officer of health must be notified when the sodium concentration exceeds 20 mg/L so thatthis information may be communicated to local physicians for their use with patients on sodiumrestricted diets.)

8. A pesticide not listed in Table D of Schedule 2 is detected. (Corrective action: Re-sample, take acorresponding raw water sample and analyze. On confirmation, call the local medical officer ofhealth again and consult. Drinking water should be free of pesticides and every effort should bemade to prevent pesticides from entering raw water sources. Pesticides may be reported by theirmost common trade name, a listing of which, called the Compendium of Scheduled Pesticides isaccessible on the internet through the web site of the Ministry of the Environment atwww.ene.gov.on.ca.)


Spring 2001 23

Appendix 2


CHEMICAL/PHYSICAL STANDARDS

PARAMETER MAC (mg/L) IMAC (mg/L)Alachlor 0.005Aldicarb 0.009Aldrin + Dieldrin 0.0007Arsenic 0.025Atrazine + N-dealkylated metabolites 0.005Azinphos-methyl 0.02Barium 1.0Bendiocarb 0.04Benzene 0.005Benzo(a)pyrene 0.00001Boron 5.0Bromoxynil 0.005Cadmium 0.005Carbaryl 0.09Carbofuran 0.09Carbon Tetrachloride 0.005Chloramines 3.0Chlordane (Total) 0.007Chlorpyrifos 0.09Chromium 0.05Cyanazine 0.01Cyanide 0.02Diazinon 0.02Dicamba 0.121,2-Dichlorobenzene 0.21,4-Dichlorobenzene 0.005Dichlorodiphenyltrichloroethane (DDT)+Metabolites 0.031,2-Dichloroethane 0.0051,1-Dichloroethylene(vinylidene chloride) 0.014Dichloromethane 0.052-4-Dichlorophenol 0.92,4-dichlorophenoxyacetic acid(2,4-D) 0.1Diclofop-methyl 0.0009Dimethoate 0.02Dinoseb 0.01Dioxin and Furan 0.000000015a

Diquat 0.07Diuron 0.15Fluoride 1.5b

Glyphosate 0.28Heptachlor+Heptachlor Epoxide 0.003Lead 0.01c

Lindane (Total) 0.004Malathion 0.19Mercury 0.001Methoxychlor 0.9Metolachlor 0.05


24 Spring 2001

PARAMETER MAC (mg/L) IMAC (mg/L)Metribuzin 0.08Monochlorobenzene 0.08Nitrate (as nitrogen) 10.0Nitrite (as nitrogen) 1.0Nitrate + Nitrite (as nitrogen) 10.0Nitrilotriacetic Acid (NTA) 10.0Nitrosodimethylamine (NDMA) 0.000009Paraquat 0.01Parathion 0.05Pentachlorophenol 0.06Phorate 0.002Picloram 0.19Polychlorinated Biphenyls (PCBs) 0.003Prometryne 0.001Selenium 0.01Simazine 0.01Temephos 0.28Terbufos 0.001Tetrachloroethylene (perchloroethylene) 0.0302,3,4,6-Tetrachlorophenol 0.10Triallate 0.23Trichloroethylene 0.052,4,6-Trichlorophenol 0.0052,4,5-Trichlorophenoxyacetic acid (2,4,5-T) 0.28Trifluralin 0.045Trihalomethanes 0.100d

Turbidity 1.0 NTUUranium 0.10Vinyl Chloride 0.002

Notes:

Short forms:MAC - Maximum Acceptable ConcentrationNTU - Nephelometric Turbidity UnitIMAC - Interim Maximum Acceptable Concentration mg/L - milligrams per litre

Footnotes:

a Total Toxic equivalents when compared with 2,3,7,8-TCDD (tetrachlorodibenzo-p-dioxin).

b Where fluoride is added to drinking water, it is recommended that the concentration be adjusted to1.0(+/-0.2) mg/L, the optimum level for control of tooth decay.

c This standard applies to water at the point of consumption.

d This standard is expressed as a running annual average.


Spring 2001 25

Appendix 3


RADIOLOGICAL STANDARDS

Parameter MAC (Bq/L) Parameter MAC (Bq/L)Natural RadionuclidesBeryllium-7 4000. Thorium-228 2Bismuth-210 0.1 Thorium-230 0.4Lead-210 0.2 Thorium-232 0.1Polonium-210 0.2 Thorium-234 20.0Radium-224 2. Uranium-234 4.Radium-226 0.6 Uranium-235 4.Radium-228 0.5 Uranium-238 4.Artificial RadionuclidesAmericium-241 0.2 Nibium-95 200.Antimony-122 50. Phosphorus-32 50.Antimony-124 40. Plutonium-238 0.3Antimony-125 100. Plutonium-239 0.2Barium-140 40. Plutonium-240 0.2Bromine-82 300. Plutonium-241 10Calcium-45 200 Rhodium-105 300Calcium-47 60 Rubidium-81 3000Carbon-14 200 Rubidium-86 50Cerium-141 100 Ruthenium-103 100Cerium-144 20 Ruthenium-106 10Cesium-131 2000 Selenium-75 70Cesium-134 7 Silver-108m 70Cesium-136 50 Silver-110m 50Cesium-137 10 Silver-111 70Chromium-51 3000 Sodium-22 50Cobalt-57 40 Strontium-85 300Cobalt-58 22 Strontium-89 40Cobalt-60 2 Strontium-90 5Gallium-67 500 Sulphur-35 500Gold-198 90 Technetium-99 200Indium-111 400 Technetium-99m 7000Iodine-125 10 Tellurium-129m 40Iodine-129 1 Tellurium-131m 40Iodine-131 6 Tellurium-132 40Iron-55 300 Thallium-201 2000Iron-59 40 Tritium 7000Manganese-54 200 Ytterbium-169 100Mercury-197 400 Yttrium-90 30Mercury-203 80 Yttrium-91 30Molybdenum-99 70 Zinc-65 40Neptunium-239 100 Zirconium-95 100


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Spring 2001 27

Appendix 4

Strength of Association Between Illness and Water

Once an outbreak is determined, it is important to assess the likelihood of it being waterborne,particularly if the source affects a community. Any corrective actions or public advisoriesinvolving interagency cooperation and public or other client acceptance, would be facilitated if theoutbreak's link to water could be demonstrated. The following is an algorithm from the PublicHealth Laboratory Systems of the United Kingdom which may be of assistance.

Strength of Association of Outbreak to Water

Microbiology/WaterQuality

APathogen identified in clinicalcases is also found in water.

BWater quality failure and/or watertreatment problem of relevance butoutbreak pathogen is not detectedin water.

Epidemiology

CEvidence from an analytical (casecontrol or cohort) studydemonstrates association betweenwater and illness.

DDescriptive epidemiology suggeststhat the outbreak is water relatedand excludes obvious alternativeexplanations.

Strongly associated if (A + C) or (A + D) or (B + C);Probably associated if (B + D) or C only or A only;Possibly associated if B only or D only


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Spring 2001 29

Appendix 5

Source of Contaminated Water

Factors that have Contributed to Waterborne Disease Outbreaks According to Various WaterSources and Systems

Source/system FactorsSurface water Ingestion of untreated or improperly treated surface water

Contamination of watershed by human or animal faecesUse of contaminated surface water for supplementary water sourceOverflow of sewage or outfalls near water intakeHeavy rains and/or floodingDead animals in stream or reservoirLive mammals and birds in stream, reservoir or watershed

Ground Water Overflow of seepage or sewage into well or springSurface runoff into well or springContamination through limestone or fissured rockHeavy rains and/or floodingSeepage from abandoned wellContamination of raw-water transmission line or suction pipeImproper well constructionSurface water infiltration

Inadequate treatmentof water

No disinfectionInadequate concentration or contact time of disinfectantInterruption of disinfectionInadequate filtrationInadvertent by-pass of treatment process

Storage/Transportationdeficiencies

Unprotected storage tanks, reservoirs or tanksContamination of cistern or individual storage facility by surface water runoffSewage seepage pr nearby animal clustering (feed lots)Improper or no disinfection of new storage facilityMicrobial aftergrowth in pipes and tanks

Distribution/Plumbingdeficiencies

Back siphonageCross connectionsContamination of mains during construction or repairWater main and sewer in same trench or inadequately separated

Water contact Swimming or wading in parasite-infested watersImproper filtration


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Spring 2001 31

Appendix 6

Confirmation of a Water-borne Disease Outbreak

• Laboratory Operator/Physician Notification

Hospital, private and public laboratory operators as well as physicians in the suspect area should bealerted and requested to immediately report cases for at least two incubation periods from the firstknown date of onset of symptoms from the index case. The reporting should continue until theoutbreak is declared over by the medical officer of health.

• Epidemic Curve

The depiction of cases over time may help to determine if the outbreak originated from a commonsource vehicle such as water or from person-to-person spread. A common source epidemic curvewould be expected to have a sharp rise to a peak followed by a gradual decrease in incidence. Iftransmission is occurring through a communal water distribution system and the source is continuousor intermittent, the curve would be expected to level out at the peak and continue until the cessationof contamination or the decreasing influence of contributing factors (e.g., excessive rainfall and highturbidity levels in municipal source water). Person-to-person spread should be characterized by aslow progressively rising curve over an extended period of time.

• Incubation Periods

The incubation period for a waterborne illness may be difficult to assess. Interviewing of cases mayuncover one or more persons who entered the community shortly before becoming ill or who enteredthe community for a short period and became ill after leaving. Information from such cases can beused as an estimate of the incubation period. This information can also help support the view that theoutbreak is community based and would likely be explained in terms of factors that are uniquelyattributed to that location (e.g., water distribution system).

• Comparative Community Incidence Rates

An estimate of the incidence rate of confirmed and/or suspected or the cases of acute gastrointestinalillness in the suspect community expressed per 100,000 residents during the outbreak periodcompared to similar data from neighbouring communities during the interval, may provide furtherevidence to support a waterborne disease hypothesis. If the community with the suspect drinkingwater distribution system has an obviously higher incidence rate than other studied neighbouringcommunities and they are not using the same supply, then a waterborne source hypothesis is furthersupported. If food was suspect, then the geographic distribution of cases would be expected to crossthe limits of a communal water system. Consideration should also be given to casual visitation to theoutbreak area which could contribute to an exposure risk.


32 Spring 2001

• Sales of Antidiarrhoeal Medications

Community pharmacies may have data bases for the number of antidiarrhoeal medications sold daily.Baseline data could be maintained which may help to provide early outbreak detection. High sales ofmedication compared to neighbouring communities may also support the communal waterbornespread hypothesis.

• Active Sentinel Surveillance

The daily or weekly incidence of acute gastrointestinal illness can be more reliably assessed if anumber of representative sites for active surveillance are recruited at an early point in the outbreak,such as:

• sentinel physician practices;• urgent care clinics;• hospital emergency departments;• long term care facilities; and• schools/day cares.

A number of these sites can also assist in the standardized collection of stool specimens withlaboratory-confirmed cases providing the information to assist in determining the source of theoutbreak.

• Period Prevalence Surveys for Acute Gastrointestinal Illness

Random surveys of households can help to establish the existence of an abnormally high periodprevalence of acute gastrointestinal illness in the households interviewed (see "ComparativeCommunity Incidence Rates"). Data collected may assist in estimates of the percentage ofhouseholds in a given community affected by the outbreak, i.e. a more precise measure of communitymorbidity.


Spring 2001 33

Appendix 7

Guideline for Food Establishment OperatorsDuring a Boil Water Advisory

The following information is provided to all food establishments further to a boil water advisory issued bythe Medical Officer of Health on ____________ for all users of the _______________________________municipal water supply.

1. All water that is to be provided directly to your customers for drinking purposes must be treated byboiling the tap water for at lease one (1) minute and then storing the water in clean, coveredcontainers until used for serving. An alternative to this would be using commercially available"bottled water".

2. All foods (e.g. fruits and vegetables) that need washing are to be rinsed or soaked only in tap waterthat has been boiled for at least one (1) minute.

3. Tap water used as an ingredient in any food product that will be "ready to eat" without cooking, e.g.drink mixes, puddings, jellos, etc., must be boiled for at least one (1) minute.

4. All ice must originate from tap water that has been boiled for at least one (1) minute or from acommercial ice supply distributor. Ice machines at your establishments must be emptied and notused for the duration of the boil water advisory.

5. Commercial hot water tanks that exceed 64.2°C (147.5°F) will kill the _______________________with two minutes contact time.

6. Commercial dishwashers that use hot water 64.2°C (147.5°F) or above are considered satisfactory."Low" temperature dishwashers may need to be boosted to a higher rinse temperature to provide asafe end product. Beverage glass washers that utilize a "cold" water rinse must not be used unlessthe rinse water can be changed to use hot water more than 64.2°C (147.5°F). Manually washed andsanitized dishes must be rinsed with "hot" water more than 64.2°C (147.5°F) for a final step.

7. All soft drink beverage lines connected directly to tap water for mixing must be disconnected. Usebottled or canned beverages exclusively.

8. Any employee reporting they are suffering from a diarrhoeal illness must be excluded from workand can be tested by their family doctor. They are not to return to work until symptoms havesubsided. Good handwashing should be emphasized for all staff.

Thank you for your cooperation and assistance during this difficult emergency situation. Please contactyour local health inspectors if you need to discuss these guidelines.

Adapted from a Simcoe county District Health Unit advisory.


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Spring 2001 35

Appendix 8

Guideline for Public Pool/Spa Operators

The following information is provided to all Class "A" and Class "B" public pool and all public spaoperators further to a boil water advisory issued by the medical officer of health on _____________For all users of the _________________________ municipal water supply.

1. Chlorine and bromine are widely used disinfectants in pools and spas.

2. Ensure normal chlorine levels of not less than 0.5 ppm or normal bromine levels of more than2.0 ppm are maintained in all pools. Ensure normal chlorine or bromine levels of between 5 -10 ppm are maintained in all spas. Maintenance of pH, alkalinity, calcium hardness and totaldissolved solids in their desirable ranges is also essential to assure adequate disinfection andbather comfort. Refer to Ontario Regulation, Public Pools, if you are unsure what theseranges are or call your local health inspector for assistance.

3. Ensure drinking water fountains around pools or spas are shut off. Bottled or substitutedrinking water should be made available to all bathers.

4. Bathers are to be advised that they should be careful not to ingest pool or spa water. A postedsign is recommended.

5. Special attention must also be made to ensure all bathers are showering (i.e. with warm waterand soap) prior to entering the pool or spa.

6. Should a "pool fouling accident" (i.e. vomit/stool in pool) occur, staff should:

• clear the pool or spa;• close the pool or spa immediately;• stop the recirculation pump;• remove any solid particles with a dipper screen. Disinfect the dipper screen;• vacuum any waste products not picked up by the dipper screen directly to the sanitary

sewer, not back to the filter;• superchlorinate the pool or spa to a minimum free available chlorine (FAC) level of 50

ppm and hold for 2 ½ hours, or 80 ppm for at least 1 ½ hours. Maintain the pH between7.0 and 7.2 or less during the process (see reference #19); and

• restart the circulation pump after superchlorination, and re-open the pool or spa only whenchemical levels to normal.

If the above mentioned cleaning procedures can not be carried out effectively or thestool/vomit is widely dispersed in the pool or spa, the following procedure must be used:

• drain the pool or spa;• steam clean pool or spa basin, decks and gutters;


36 Spring 2001

• refill the pool or spa and superchlorinate the recirculation and filtration systems to a levelof 80 ppm free available chlorine (FAC), keeping the pH between 7.0 and 7.2 during theprocedure; and

• re-open the pool or spa only when chemical levels return to normal.

7. Record fouling accidents in the pool or spa records. Time. Location and action taken shouldbe noted.

8. Babies, very small children and bathers who do not have control of their bowels should wearappropriate clothing to prevent faecal discharge into the pool or spa.

Thank you for your cooperation and assistance during this difficult emergency situation. Please contactyour local health inspectors if you need to discuss these guidelines.

1996Adapted from the Simcoe County District Health Unit guideline


Spring 2001 37

Appendix 9

Guideline for Health Care Institution Infection and Day Care Facilities Staff during a Boil WaterAdvisory

Infection Control Staff

During a Boil Water Advisory

• All employees with diarrhoeal illness should be regulated by standard rules of exclusion from work.

• Patients, children and employees should not consume untreated tap water, ice or drinks made fromtap water.

• Cafeteria and food service staff should not serve water, ice or drinks made with untreated water, orraw foods rinsed with untreated water.

• Dishwashing machines that have a dry cycle or a final rinse that exceeds 64.2°C will adequatelydisinfect dishes.

• Water can be disinfected by:

- boiling at a rolling boil for one minute; or- distilling; or- filtering through a "reverse osmosis" filter an "absolute one micron" filter or a filter certified to

remove Cryptosporidium or Giardia under NSF International Standard #53 for either "cystremoval" or "cyst reduction". Ultraviolet light treatment of water is not effective againstCryptosporidium or Giardia.

Upon Lifting of a Boil Water Advisory

• Any water-using fixture or piece of equipment should be re-started and flushed in accordance withthe manufacturer's specifications. This may vary from fixture to fixture. Your facilities engineerand/or the manufacturer should be consulted when you re-start the equipment.

• Run cold water faucets for one minute before using the water.

• Run Drinking Fountains for one minute before using the water.

• Backwash pool filters and change media or water as warranted.

• Run water softeners through regeneration cycle.

• Hot water heaters set below 64.2°C should be drained and refilled.

1995, Adapted from the Centers for Disease control and Prevention (CDC), Atlanta guideline


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Spring 2001 39

Appendix 10

NOTIFICATION OF DRINKING WATER ADVISORYTO PUBLIC HEALTH BRANCH (required pursuant to s. 86.2 of the Health Protection and Promotion Act)

Please immediately fax to Rob Nickol, fax: (416) 327-7439

Health Unit: Date:

Contact Name/Phone Number:

GENERAL INFORMATIONTYPE OF WATER SUPPLY

↑ Municipal Name:

↑ Privately Operated Under OWRA Name:

Is this water supply subject to O.R. 459/00, Drinking Water Protection Regulation? ↑ Yes ↑ No

SOURCE OF WATER SUPPLY

↑ Surface Water ↑ Ground Water

↑ Other:

BOIL WATER ADVISORY (BWA)

Reason(s) for BWA: ↑ E. coli ↑ Total Coliform↑ Lack/Absence of Free Chlorine Residual

↑ Other:

Date BWA issued: / / Date Lifted: / / DD MM YYYY DD MM YYYY

Please advise the PHB when the BWA is lifted

Is the issuance of the BWA related to illness? ↑ Yes ↑ No

If yes, number ill Cause if known:

Is a press release issued? ↑ Yes ↑ No Please attach copy of Press Release

NON-MICROBIOLOGICAL DRINKING WATER ADVISORY

Reason(s) ↑ MAC or IMAC Exceedence

↑ Other

Date Advisory issued: / / DD MM YYYY


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Spring 2001 41

Appendix 11

Table D

Pesticides and PCB

Alachlor DDT ParathionAldicarb 2,4-D PentachlorophenolAldrin+Dieldrin Diclofop-methyl PhorateAtrazine Dimethoate PicloramAzinphos-methyl Dinoseb PCBBendiocarb Diquat PrometryneBromoxynil Diuron SimazineCarbaryl Glyphosate TemephosCarbofuran Heptachlor+heptachlor epoxide TerbufosChlordane (Total) Lindane (Total) 2,3,4,6-TetrachlorophenolChlorpyrifos Malathion TriallateCyanazine Methoxychlor 2,4,6-TrichlorophenolDiazinon Metoachlor TrifluralinDicamba Metribuzin 2,4,5-T2,4-Dichlorophenol Paraquat


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Spring 2001 43

Appendix 12

_____________________________________________________________Health Unit

BOIL WATER ADVISORYTo Consumers of

________________________

Water Supply

The Medical Officer of Health, Dr. _______________________, is advising users of the water to bringwater to a rolling boil for at least one minute prior to using it for domestic purposes e.g., drinking,making infant formula and juice, brushing teeth, washing raw foods and making ice.

The reason for the advisory is that the Medical Officer of Health has sample results that show thepresence of __________________________ above the requirements in Ontario Regulation 459(Drinking Water Protection).

This advisory measure is in place until such time as further bacteriological tests prove the water to besafe.

A copy of "How to use water safely during a boil water advisory" is available from the health unitoffice or on the Ministry of Health and Long-Term Care website at:

_____________________________Dr. …………………………


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Spring 2001 45

Appendix 13

HEALTH FACTS WATER SAFETY

How to use water safely during a "boil water advisory

What are the reasons for a "boil water advisory"?

There are different reasons for issuing a boil water advisory.1. A boil water advisory is based on information other than bacteriological examination indicating that the water in

not safe to drink e.g., lack or absence of disinfection residual in the drinking water.

2. A boil water advisory may be based on bacteriological (microbial) examination, including the finding ofbacteria or parasites.

3. A boil water advisory may follow the occurrence of an outbreak of illness in the community that has beenlinked to consumption of the water.

The extent of restriction on water use depends on the situation and the reason for issuing a boil water advisory. Alwaysfollow your own health unit's recommendations on water use.General recommendations on how to use the water if a boil water advisory has been issued in yourcommunity.

How do I use water when the boil water advisory has been issued?

The water should NOT be used for drinking, making infant formula and juices, cooking, making ice, washingfruits, vegetables or brushing teeth. For these purposes, boiled water or bottled water should be used. The watershould be brought to a rapid rolling boil and boiled for 1 minute. If there are children in the home, place the pot on theback burner to avoid scalds. Boil only as much water in a pot as you can comfortably lift without spilling. Discard all icemade previously and disinfect the ice cube trays. Make ice using boiled, cooled water.

Can I take a bath?

Adults and teens may shower with untreated water as long as no water is swallowed. Older children could also begiven a shower with a hand held showerhead, avoiding the face. Younger children should be sponge-bathed instead ofbathing in a tub because they are likely to swallow tub water.

Can I use the water for handwashing?

If the boil water advisory has been issued as a precaution and there is no outbreak of human illness, there isno need for additional hand disinfection with bleach solution or alcohol using the measures described below.If the boil water advisory has been issued because of an outbreak, water can be used for handwashing after thefollowing emergency water treatment: Place 1.5 oz (about 45 ml) liquid household bleach in 10 gallons (45 litres)water. Mix and let stand for at least 10 minutes prior to use.

How else can I disinfect my hands?

You can use alcohol-based hand disinfectants, containing more than 60% alcohol. These products are widely used inthe health care setting after washing hands or in situations when water is not available. Please refer to information on"Hand Hygiene". The wet wipes used for cleaning babies at diaper change are not effective for disinfecting hands andshould not be used for this purpose.


46 Spring 2001

My child was ill with diarrhea. Should I clean/disinfect toys?

Yes, toys should be cleaned and disinfected. If the toys are visibly soiled, wash them first with soap and water andthen disinfect with a freshly prepared bleach solution (1/4 cup (about 60 ml) bleach in to 1 gallon (4.5 litres) of water).Dip toys in to this solution and air-dry them. Cloth and plush toys could be washed or dry-cleaned.

I have a dishwasher. Is it safe to use?

If your dishwasher has a hot setting, it safely disinfects dishes. If your dishwasher does not have a hot setting, afterfinishing the cycle, soak dishes for 1 minute in a solution of 1oz (30 ml) of bleach mixed with 3 gallons of lukewarmwater (13.5 litres). Let dishes air dry.

I wash dishes by hand. How do I disinfect them?

You could use boiled water for washing dishes. Dishes washed in soap and hot water can also be rinsed in boiledwater or disinfected with the following bleach solution. Mix 1 oz. (about 30 ml) bleach in to 3 gallons (13.5 litres) ofwater at room temperature for at least 1 minute. Let dishes air dry.

What is disinfection?

Disinfection is a cleaning process which destroys most disease-causing micro-organisms (pathogens).

How do I disinfect countertops, chopping boards or utensils which have come into contactwith raw meat?

Countertops, chopping boards or utensils which have come into contact with raw meat should be washed with soapand hot water first, then disinfected with a bleach solution stronger than that used for emergency hand disinfection. Mix1/4 cup (about 60 ml) bleach in to 1 gallon (4.5 litres) water for this purpose. Do not reuse or store this solution, butmake it fresh daily.

Should I change the way I am doing laundry?

No, continue doing laundry the way you usually do. If you have to launder sheets heavily soiled with faeces, carefullyremove soil before you place the sheets into the washer, without much agitation of the cloth. Use rubber gloves whenhandling heavily soiled sheets.

Is the water safe to fill wading pools for children?

No, the water is not safe to use in wading pools. Water usually gets into the mouths of small children, providing apossibility for infection.

I have a water filtration device installed. Does this make the water safe for drinking orcooking?

No. Filtered water should also be brought to a rolling boil for 1 minute before drinking or using it for cooking.

My doctor told me I am immunocompromised. What should I do?

Always follow your physician's and dietitian's advice. You might be advised to use bottled water or to boil water fordrinking/cooking, even in the absence of a boil-water advisory.


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How does the medical officer of health decide when to "lift" a boil water advisory?

The Ontario Drinking Water Objectives (ODWO) state that the medical officer of health should continue the boil wateradvisory until the objectives in the ODWO are no longer exceeded in two consecutive sets of samples taken from allparts of the distribution system that has been affected. The objectives address issues that can affect health, such asthe presence of E. coli. The medical officer of health may choose not to lift the boil water advisory even if twoacceptable samples are obtained.

What should I do after the boil water advisory is lifted?

Run cold water faucets for 1 minute before using the water. Run drinking fountains for 1 minute before using the water.Flush all garden hoses by running cold water through them for 1 minute. Run water softeners through a regenerationcycle. Drain and refill hot water heaters set below 45°C (normal setting is 60°C)See also:

• E. coli Bacteria• Hand Hygiene