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A comparative analysis of current microbial water quality risk assessment and management practices in… Dunn, Gemma; Cook, Christina; Prystajecky, Natalie; Harris, Leila Jan 15, 2014

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lBritish Columbia andGemma Dunn a,⁎, Leila Harris b, Cha Program on Water Governance, University of British Columability anusalem, Me, Univernt pracassessmd mana, even witationsprotozoa and viruses)Science of the Total Environment 468–469 (2014) 544–552Contents lists available at ScienceDirectScience of the Totj ourna l homepage: www.e lsen access under CC BY license.Microbial risk assessment and management of water quality is animportant concern and focus of governmental regulation and scientificare ubiquitous in aquatic environments. While most microorganismsare benign and serve essential ecosystem functions, some can be (orproduce substances that are) harmful to ecosystem and human health.© 2013 The Authors. Published by Elsevier B.V.1. Introduction inquiry (WHO, 2004). Microorganisms (bacteria,OpeArticle history:Received 29 June 2013Received in revised form 2 August 2013Accepted 2 August 2013Available online 19 September 2013Editor: Damia BarceloKeywords:Microbial pathogensRisk assessment and managementCanadaBritish ColumbiaOntarioBacteria, protozoa and viruses are ubiquitous in aquatic environments and may pose threats to water quality forboth human and ecosystem health. Microbial risk assessment and management in the water sector is a focus ofgovernmental regulation and scientific inquiry; however, stark gaps remain in their application and interpreta-tion. This paper evaluates how water managers practice microbial risk assessment and management in two Ca-nadian provinces (BC and Ontario). We assess three types of entities engaged in water management along thesource-to-tap spectrum (watershed agencies,water utilities, andpublic health authorities).Weanalyze and com-pare the approaches used by these agencies to assess andmanagemicrobial risk (including scope, frequency, andtools).We evaluate key similarities and differences, and situate themwith respect to international best practicesderived from literatures related to microbial risk assessment and management. We find considerable variabilityin microbial risk assessment frameworks and management tools in that approaches 1) vary between provinces;2) vary within provinces and between similar types of agencies; 3) have limited focus on microbial risk assess-ment for ecosystemhealth and 4) diverge considerably from the literature on best practices.We find that risk as-sessments that are formalized, routine and applied system-wide (i.e. from source-to-tap) are limited.We identifykey limitations of current testing methodologies and looking forward consider the outcomes of this researchwithin the context of new developments inmicrobial water quality monitoring such as tests derived from geno-mics and metagenomics based research.a b s t r a c ta r t i c l e i n f o⁎ Corresponding author. Tel.: +1 604 822 6474.E-mail address: gemma.dunn@ubc.ca (G. Dunn).0048-9697 © 2013 The Authors. Published by Elsevier B.Vhttp://dx.doi.org/10.1016/j.scitotenv.2013.08.004b Institute for Resources, Environment, and Sustainc Geography Department, Hebrew University of Jerd Department of Pathology and Laboratory MedicinH I G H L I G H T S• Canadian risk management and assessme• We found limited focus on microbial risk• Microbial risk assessment frameworks an• Different agencies use different risk tools• Metagenomics tools may address key limristina Cook c, Natalie Prystajecky dbia, 439-2202 Main Mall, Vancouver, BC V6T 1Z4, Canadad Program on Water Governance, University of British Columbia, 421-2202 Main Mall, Vancouver, BC V6T 1Z4, Canadaount Scopus, Jerusalem, 91905, Israelsity of British Columbia, G227-2211 Wesbrook Mall Vancouver, Vancouver, BC V6T 2B5, Canadatices diverge considerably from the literature.ent for ecosystem health.gement tools in Canadian provinces are variable.ithin the same watershed.to current risk assessment and management.Ontario, Canadaassessment and management practices inA comparative analysis of current microbia.Open access under CC BY license.water quality riskal Environmentv ie r .com/ locate /sc i totenvMicrobially-contaminated drinking water has long been implicated inhuman illness and historically, attention has focused on finished (end-product or tap) water quality. However, these strategies are increasing-ly regarded as insufficient to prevent disease outbreaks andmore atten-tion has been paid to preventing illness from source-to-tap (Byleveldet al., 2008; Summerscales and McBean, 2011). Furthermore, it hasbeen increasingly noted that poormicrobial water quality can be harm-ful to aquatic organisms and ecosystem function (Gozlan et al., 2006;Miller et al., 2002, 2011; Weitz and Wilhelm, 2012). Human healthand ecosystemhealth are implicitly related, particularlywhen consider-ing microbial risk along the source-to-tap spectrum (Serveiss and545G. Dunn et al. / Science of the Total Environment 468–469 (2014) 544–552Ohlson, 2007; Davies and Mazumder, 2003).A comprehensive understanding of the risks (both existing and po-tential) to water quality can be achieved through evaluation of the entirewater supply system. This concept is known as ‘source-to-tap’, whereby ahigh quality source, in combinationwith effective treatment and safe dis-tribution, supported by legislation and ongoingwater quality testing, willyield water that is safe for human consumption. As a cornerstone ofdrinking water quality risk assessment (Hrudey, 2011; Krewski et al.,2002), the source-to-tap framework has, to date, been mobilized with afocus on human health. Comprehensive risk assessment and manage-ment approaches that include the entire source-to-tap gradient aremore likely to successfully address not only point-source pollution butalso the more complex impact of non-point sources of water contami-nants within a given watershed (Phillips, 1988). Sound risk assessmentand management is crucial for both drinking water provision (Byleveldet al., 2008;Hamilton et al., 2006; Jayarante, 2008) aswell as broader eco-systemprotection (Serveiss andOhlson, 2007). Indeed, riskmanagementin a source to tap framework is thought to be critical given the recogni-tion that hazards are innumerable and resources to deal with them arelimited (Dominguez-Chicas and Scrimshaw, 2010; Gelting, 2009;Hamilton et al., 2006; Hrudey, 2004, 2009).In Canada, some aspects of microbial testing for water quality aremandated across all jurisdictions (Escherichia coli and total coliformmonitoring at tap for drinking water). However, beyond general guide-lines recommending the adoption of a multi-barrier approach1 by theCanadian Council of Ministers of the Environment Water Quality TaskGroup and the Federal–Provincial–Territorial Committee (CCME FPTC)on DrinkingWater, there is no overarching Canadian framework specif-ic to microbial risk assessment and management, anywhere along thesource to tap framework (CCME, 2004). In the absence of a mandatednational framework, considerable diversity in risk assessment andman-agement of microbial water contamination exists across the country.Little is known about the gap (or variance) between the theory andpractical application of risk assessment and management. This studyaims to address that gap by examining the ways different Canadianagencies and practitioners apply concepts and tools related to microbialassessment andmanagement. Our objective is to describe current prac-tices in two Canadian provinces, British Columbia (BC) and Ontario, andto situate them with respect to the literature and best practices. Ourevaluation extends across the source-to-tap gradient and is attentiveto both ecosystem and human health concerns. We do not attempt tocompare or analyze the wide range of formalized risk assessment andmanagement tools currently available. Rather we ascertain whichones, if any, practitioners are currently using. While we recognize theimportance of chemical or other contamination risks, these consider-ations are beyond the scope of this study.Our research included a literature review of current practices (seeSection 2) and interviews with practitioners from selected agencies weexpect are engaged in microbial risk assessment and management, fromsource-to-tap. Section 3 outlines the methods used. In the results(Section 4) we highlight key water quality monitoring issues as well asthe considerable variability in risk assessment and management ap-proaches betweenprovinces and among agencies. In Section5,wediscusscurrent practices in light of best practices derived from the literature andfind considerable divergence in on the ground practices. In Section 6, we1 The multi-barrier approach comprises of six core elements: source water protection;effective water treatment; secure water distribution system; water quality monitoring(at source, treatment plant, and tap); operator training and an emergency response proce-dure. Central to themulti-barrier approach is the assessment andmanagement of the risksto water safety that can be addressed by each barrier.consider the implications of these findings, particularly in light of recom-mendations in the literature for preventative, multi-barrier approachesthat consider both ecosystemhealth and humanhealth concerns. Lookingforward we consider the outcomes of this research within the context ofnew developments in microbial water quality monitoring such as testsderived from genomics and metagenomics based research.2. Risk assessment and managementThe terms risk assessment and risk management are intrinsicallylinked and often conflated; however, their meanings are quite distinct.Risk assessment is a scientifically based process involving four keysteps: hazard identification/assessment/measurement; hazard charac-terization (e.g. dose–response analysis); exposure assessment; andrisk characterization (Hunter et al., 2003). Risk assessment undertakenwithin the context of a source-to-tap framework should offer an im-proved, integrated understanding of the various components of thewater supply system, their strengths and weaknesses, and the existingand potential threats to water quality so that informed decisions canbe made. Risk management refers to the control options, the legal con-siderations and risk management decisions (including economic andsocial factors) to reduce or mitigate risk. This includes the task of man-aging the assessed risks in the face of uncertainty, balancing consider-ation of potential hazards with available treatment and mitigationstrategies as well as resources (Hamilton et al., 2006).In many sectors risk assessment and management are central to op-erations and protocols. Although methods may vary, risk assessmentandmanagement practices have been utilized for decades in the energyutility sector, in industries such as automotive and food, and amongHigh Reliability Organizations (HROs) such as aviation and nuclearpower plants. Comparatively speaking, formalized, explicit and routinerisk assessment practices in the water sector are relatively newer andless widespread (Egerton, 1996; Pollard et al., 2004).In 2004, The World Health Organization (WHO) published theirfirst set of guidelines emphasizing risk-based management ofwater (WHO, 2004). In doing so, the WHO advocated the applicationof broader, more comprehensive approaches to manage water qual-ity challenges. This is indicative of a move away from a reactive ap-proach of focusing on treated water (narrowly focusing on end-product testing at the tap), which can only highlight a potentialhealth problem after the water has been consumed, toward a pre-ventative risk management approach that looks comprehensivelyat the entire water system from the source-to-tap (Hrudey, 2003).Increasingly, preventative approaches are considered to be more re-liable and cost effective to protect public health (Byleveld et al.,2008; Dominguez-Chicas and Scrimshaw, 2010; Hamilton et al.,2006). Coupled with this has been a transition from implicit (impliedbut not formally expressed) to explicit (formalized and routine)frameworks for risk assessment and management, particularly with-in the international water utility sector (Hrudey et al., 2006; Pollardet al., 2004; Summerill et al., 2010a). This is characterized by the in-troduction of procedures such as Hazard Analysis and Critical Con-trol Points (HACCP), Qualitative Microbial Risk Assessment(QMRA) andWater Safety Plans (WSP). Table 1 provides a summary,with key citations, of several risk assessment tools currently avail-able and in use.Perhaps most notable of all these approaches is the WSP (based onHACCP and advocated by theWHO), which is a risk-based preventativeapproach to managing drinking water safety from catchment to con-sumer (source-to-tap). A WSP is an iterative process whereby thethreats to the system; the capacity of the system to cope with threats;the ability to respond if barriers fail; and measures to improve the sys-tem are all characterized and incorporated into planning (Bartramet al., 2009; Gelting, 2009; Hrudey, 2011). As such, WSPs involve an ex-plicit risk assessment andmanagement philosophy (Hrudey et al., 2006;Pollard et al., 2004; Summerill et al., 2010a).Table 1Selection of risk assessment & management tools identified in the literature.Risk assessment tool Brief description ReferenceFailure Modes andEffects (Criticality)Analysis (FME(C)A)A systematic process toidentify potential failuremodes (causes and effects)based on experience withsimilar processes.(Widely used inmanufacturing industries)Dominguez-Chicas andScrimshaw (2010), Hamiltonet al. (2006), Pollard et al.(2004)Critical Control Points(CCP)A point, step or procedure(i.e. a critical failure area)that can be identified in asystem.(Derived from FMEA)Hamilton et al. (2006),Summerill et al. (2010a),Yokoi et al. (2006)Hazard Analysis andCritical ControlPoints (HACCP)A preventative riskmanagement system inwhich a point, step orprocedure (i.e. a criticalfailure area) can be identifiedin a system to whichcorrective actions can beapplied so that a potentialhazard can be prevented,eliminated, or reduced to anacceptable level. Alsoincludes verificationprocedures to ensure theplan is adequate.(Builds on CCP. Originallydeveloped in the foodindustry initially for NASA.Nowwidely used in food andpharmaceutical industries)Davison et al. (2005),Dominguez-Chicas andScrimshaw (2010), Hamiltonet al. (2006), Miller et al.(2005), Pollard et al. (2004),Yokoi et al. (2006), Jayarante(2008)Water Safety Plans(WSP)Comprehensive riskassessment andmanagement plan to identifyand prioritize potentialthreats to water quality ateach step in a specificsystem's water supply chain(from source to tap)implementing best practicesto mitigate threats todrinking water.(Derived from HACCP andthe multi-barrier approach)Ashbolt (2004), Davison et al.(2005), Byleveld et al.(2008), Hamilton et al.(2006), Schijven et al.(2011), Smeets et al. (2010),Summerill et al. (2010a,2010b), Vieria (2007), Yokoiet al. (2006), Jayarante(2008), Miller et al. (2005),Gelting (2009), Austin et al.(2012), Hrudey (2011),Bartram et al. (2009),Gunnarsdottir et al. (2012)Total QualityManagement(TQM)A holistic, integratedmanagement approachwhereby all members of anorganization participate inmaintaining and improvingprocesses, products, services.Also described as a culturalinitiative that fosters acollaborative environmentbetween departments withinan organization to improveoverall organizationalquality.O' Connor (2002), Hamiltonet al. (2006), Hrudey (2003,2004)QuantitativeMicrobial RiskAssessment(QMRA)A systematic quantitativeassessment process toestimate the risks of humanexposure to an array ofmicroorganisms that cancause infectious diseaseoutbreaks. Combines doseresponse information for theinfectious agent withinformation on thedistribution of exposures.Haas et al. (1999), Ashbolt(2004), Ashbolt et al. (2010),Cool et al. (2010), Schijvenet al. (2011), Signor andAshbolt (2006), Smeets et al.(2010), Goss and Richards(2008), Benke and Hamilton(2008)InternationalOrganization forStandardization(ISO) 14001 &9001aAn internationallyrecognized family of certifiedstandards approved throughindependent assessment.14001 — EnvironmentalManagement: a systematicapproach to minimizeServeiss and Ohlson (2007),Jayarante (2008), Miller et al.(2005), Summerill et al.(2010a), Vieria (2007)546 G. Dunn et al. / Science of the Total Environment 468–469 (2014) 544–552Table 1 (continued)Risk assessment tool Brief description Referencenegative impacts, increaseoperational efficiency andidentify cost savings,underpinned by continuousimprovement.9001 — QualityManagement: a frameworkfor an organization to focuson customer and productrequirements, processperformance andeffectiveness in the systemsdelivery with a key focus oncontinuous improvementand objective measurement.Ecological RiskAssessment &Regional RiskModelA process to evaluate thepotential adverse effects ofhuman activities on theecological health of anecosystem at a particular site.An explicit expression of theenvironmental value(species, ecological resource,or habitat type) that is to beprotected.Serveiss and Ohlson (2007)Catchment RiskManagementRisk analysis of water supplyat a catchment-scale. Con-siders a multitude of possiblesources of hazardous events,caused by natural or humanfactors such as wild animalserosion, land use, industry,traffic, and recreational ac-Miller et al. (2005)The uptake of explicit, formalized and routine risk assessment andmanagement approaches in the water sector is gaining momentumaround the world with a number of jurisdictions introducing policyand legal requirements. For example, the Dutch Drinking Water Act(2001) created a legal requirement for water utilities to use QMRA fordrinking water from surface and vulnerable groundwater (Schijvenet al., 2011). Water Safety Plans in particular are gaining popularity andare widely used across Europe, Africa and the Americas (Gelting, 2009).Iceland legislated drinking water utilities use Water Safety Plans in1995 (Gunnarsdottir et al., 2012). The Australian DrinkingWater Guide-lines promote the implementation of Water Safety Plans in states andterritories. For example, New SouthWales has recommendedwater sup-pliers implementWSPs, and Victoria has regulated utilities to implementrisk-based management plans through the Water Safety Act 2003(Byleveld et al., 2008).In Canada, it has been increasingly emphasized that a transitionfrom implicit to explicit approaches in the area of water safety isnecessary, particularly since the Walkerton crisis of 2000 and the re-port of the Walkerton Inquiry in 2002. Recommended approachesfor securing drinking water include risk assessment and manage-ment, the source-to-tap approach, and WSPs (Ivey et al., 2006;Hrudey, 2011; O' Connor, 2002).3. Methods3.1. RationaleTo date, explicit material which links the theory of microbial assess-ment and management to actual practice is not readily available. InCanada, each province has a unique approach to water governance intivities.a In addition, ISO standard for Risk Management (ISO 31000:2009) provides principlesfor effective risk management and corporate governance. However, unlike ISO 14001 and9001, ISO 31000 cannot be used for certification purposes, although it does provide guid-ance for internal or external audit programs.general, and microbial risk assessment and management in particular.Key differences include regulatory requirements and provincial guide-lines on risk assessment and management (Cook et al., in press;Ngueng Feze et al., under review). Furthermore, within a single water-shed multiple stakeholders engage in microbial risk assessment andmanagement including watershed authorities, water utilities and thehealth authorities. Because each agency has a distinct mandate, priori-ties and interests in water quality, we hypothesize that microbial riskmanagement approaches will differ. We predict that health authoritiesand water utilities may prioritize risk assessment for human health (in-cluding drinking or recreational water), while watershed authoritieswill stress broader ecosystem health considerations in source water.We also expect important differences across these entities based on547G. Dunn et al. / Science of the Total Environment 468–469 (2014) 544–552theirmandates, data availability, andmonitoring and assessment capac-ity. It is precisely these types of differences that have not been previous-ly documented and that our study aims to uncover.3.2. Selection of intervieweesThe research employed a case study approach using semi-structured interviews to gather qualitative data (Yin, 2003;Summerill et al., 2010b; Taylor et al., 2013). In the two Canadianprovinces studied (BC and Ontario) interviews were conductedwith experienced personnel from select agencies to provide insightsinto “on-the-ground” risk assessment and management practicesalong the source-to-tap spectrum. Three case study watershedswere selected in each of the two provinces (Abbotsford, Kelownaand Victoria in BC and Toronto, Kitchener–Waterloo and Ottawa inOntario). In each of the six watersheds, we examined the samethree types of agencies that we anticipated would be actively en-gaged in microbial risk management (from source-to-tap): water-shed authorities, water utilities and health authorities. Specificcriteria for case study selection included type of: watershed (urbanor mixed urban–rural); source water (lake, reservoir or river; areasserved exclusively by groundwater sources were excluded); drink-ing water treatment (e.g. chlorination, UV and/or filtration); waterpurveyor management (e.g. municipal government, private utility);population served (e.g. medium (N10,000) to large drinking watersystems (N90, 000)); and historical water quality or quantity chal-lenges (Table 2).3.3. Collection of dataNarrative data was collected through eighteen semi-structuredinterviews (conducted by telephone, lasting approximately 1 h)with practitioners employed in these agencies including water sys-tems operators, municipal and provincial employees. This social sci-ence research approach enabled sufficiently open discussion withexperienced practitioners to reveal nuances of microbial risk prac-tices while ensuring interview discussions did not stray too farfrom the research objectives (Summerill et al., 2010a; Taylor et al.,Table 2Case study selection.Watershed authority Water utility Health authorityBC Fraser Valley Regional District Abbotsford Fraser Health AuthorityOkanagan Basin Water Board Kelowna Interior Health AuthorityCapital Regional DistrictWatershedVictoria Vancouver Island HealthAuthorityON Toronto ConservationAuthorityToronto Toronto Regional HealthAuthorityGrand River ConservationAuthorityKitchener–WaterlooWaterloo Health AuthorityRideau Valley ConservationAuthorityOttawa Ottawa Public Health2013). We sought to interview those with expertise in water manage-ment and policy, specifically individuals who would be most familiarwith the day-to-day microbial risk assessment and management ap-proaches engaged by these agencies. The narrative data presentedhere reflects the knowledge and opinions of the interviewees. Evidenceof risk assessment and management practices and policies (such asHACCP or TQM reports) was not requested.Twenty-three interview questions addressed four key themes:1) how microbial risk is measured and assessed by the organization(including what data is collected, types of risk assessment toolsused, and interpretation of results); 2) how the organization man-ages microbial risk (including risk management plans); 3) how riskis communicated (including sharing of information internally andexternally with policy makers and other stakeholders); and 4) howpolicy and legislation affects ‘on-the-ground’microbial risk manage-ment practices. The interviews were recorded, transcribed and qual-itatively analyzed using theme codes (overarching issues) based onthe questions asked of participants and sub-theme codes (specificpoints that fit within an overarching theme) derived from the con-tent of the discussions. Free and informed consent of the participantswas obtained; the study protocol was approved by the University ofBritish Columbia, Vancouver, Canada, Behavioral Research EthicsBoard (H12-01626, July 2012).4. ResultsFour core themes emerged from the interviews: issues pertaining towater quality monitoring; limited and variable application of risk as-sessment tools; limited use of risk management plans; and significantdifferences in risk assessment practices across the two study provinces.4.1. Water quality monitoringWater quality monitoring is the first step toward microbial risk as-sessment and management (characterization and measurement of thehazard). In both provinces water utilities are the primary collectors ofmicrobial water quality data, often (but not always) sharing the test re-sults with health authorities and watershed authorities. Some healthauthorities and watershed authorities conduct/enforce microbial sam-pling, but the extent and drivers for undertaking their own samplingare highly varied.4.1.1. Microbial monitoringE. coli and total coliforms are themost commonlymeasuredmicrobialwater quality indicators in accordance with legislated requirements (BCReg. 200/2003DrinkingWater Protection Regulation; O. Reg. 169/03On-tario Drinking Water Quality Standards), followed by indirect measures(primarily water treatment process indicators) such as turbidity andchlorine residual. All six water utilities test for E. coli and total coliformsand they are legally required to provide these test results to the healthauthorities. (Health authorities in turn may undertake their own addi-tional microbial sampling). Sampling type and frequency vary betweentypes of agency interviewed and between provinces (on provinces seeCook et al., in press). Unlike Ontario, BC's drinking water quality regula-tion does not prescribe regularity or sample types (see Table 3). Five ofthe 18 agencies interviewed (fromboth BC andOntario)monitor for spe-cific pathogens, typically testing for Giardia and Cryptosporidium. Acrossboth provinces a few agencies (usually water utilities) occasionally un-dertake additional testing such as Microscopic Particulate Analysis(MPA) (as a surrogate of protozoa), enterococci bacteria, Bacteroidesand bacteriophage, but this testing is not performed routinely.4.1.2. Human health focusOf the three agency types interviewed watershed authorities are theonly ones to explicitly include both the protection of human and ecosys-tem health as part of their mandate. However, not all watershed548 G. Dunn et al. / Science of the Total Environment 468–469 (2014) 544–552Table 3Comparison on microbial risk assessment and management approaches at the provincialscale.British Columbia OntarioMicrobialwaterqualitystandardsNo total coliforms, E. coli, or fecalcoliforms (B.C. Reg. 200/2003Drinking Water ProtectionRegulation)No Total coliforms or E. coli(heterotrophic plate counts) (O.Reg 169/03 Ontario DrinkingWater Quality Standards)LegislatedsamplingfrequencyPopulation-based; no regularityprescribed; sample type notspecifiedPopulation-based; regularityprescribed; sample type specifiedCentralizeddatacollectionNo — there is no centralized orprovincial water quality database.Yes — a centralized system forprovince-wide water quality datais collected andmaintained by theMinistry of Environment.Multi-barrierapproachVoluntary approach — provincialguidelines for the multi-barrierapproach have been established.The multi-barrier approach isregulated through several pro-vincial laws, incl. Safe DrinkingWater Act and the Ontario WaterResources Act, Clean Water Act.Source waterprotectionPart 5 of the BC DrinkingWaterProtection Act (BC DWPA) andRegulation (BC DWPR) enablesDrinking Water Protection Plansto be developed, but these are notcompulsory. Other regulatoryClean Water Act, 2006, S.O., 2006,c.22 mandates source protectionplanning for municipal watersources (untreated surface orgroundwater).authorities engage inmicrobial water quality monitoring in line with thismandate. One Ontario watershed authority interviewee commented thatsince the Walkerton tragedy watershed authorities are somewhat be-hooved to include E. coli in their examination of water quality but cau-tioned how this information can be used, interpreted and shared.Microbial data have limited utility when collected through infrequentgrab samples; without routine year-round sampling, this data cannot beincorporated intomostmicrobial risk assessment tools. Since water qual-itymonitoring for humanhealth falls under the jurisdiction of other agen-cies (water utilities and health authorities), three interviewees indicatedthe futility of collecting microbial water quality information, particularlywhen information is collected more rigorously by other agencies. Assuch, watershed authorities may only usemicrobial information to betterunderstand the overall state of thewatershed, rather than inclusion in for-malized microbial risk management. In the absence of this informationsomewatershed authorities indicated that they tend to focus on chemicalcontamination, which they felt they had a better capacity to monitor.4.1.3. Limitations of current testing approachesThe availability of suitable tools to characterize microbial risk is es-sential for successful risk assessment and management. Intervieweesshared five key underlying concerns related tomicrobial data collection.First, they indicated concern about their limited ability to detect specifictools with powers to protectsource waters include: Water Act,Forest and Range Practices Act,Environmental Management Actand Land Act.Riskassess-ment• No legislative imperative toconduct drinking water qualityrisk assessment, unless a DrinkingWater Officer orders a sourcewater or system assessment(DWPA 2001s.18).• No consistent risk assessmentand risk abatementmethodologies for drinking waterquality or ecosystem health.Formal risk assessment (ofdrinking water sources arerequired in accordance with theprovince's Safe Water Act 2002).Safe Drinking Water Act2002s.15(1).Riskmanage-ment• No legislative imperative toconduct drinking water riskmanagement.• No consistent risk managementmethodologies.• Emergency Responseprocedures are required under(DWPA 2001s.10).Required by legislation CleanWater Act, 2006 287/07, 54–60(this includes EmergencyResponse Procedures).pathogens, particularly the absence of tools to detect viruses in water.The limitations of using E. coli as a surrogate indicator for all pathogenswere specifically highlighted, since strong empirical evidence indicatesthat E. coli is not always predictive of pathogens occurrence, particularlyfor viruses and protozoa. I.e. the absence of E. coli is not a guarantee thata water sample is pathogen free (Harwood et al., 2005; Leclerc et al.,2001). Second, interviewees expressed concern related to the inabilityto identify the source of contaminationwith certainty. Currently, practi-tioners can target only the most likely species that may be a cause forconcern with inadequate resolution, which interviewees indicated isan ineffective use of limited resources. Third, is concern regarding thetime delay between collecting a sample and receiving the test results,highlighting the challenge to protect public health when water advi-sories depend on culture-based testing results that take 18–24 h to gen-erate (without consideration for transport time to the laboratory). Thetime lag was identified in both recreational and drinking water qualitycontexts and is also highlighted in the literature (Hrudey, 2004, 2011;Hamilton et al., 2006; Vieria, 2007; Gelting, 2009). The fourth concernis the inability to establish whether a particular microorganism willcause disease in humans (i.e. some methods cannot distinguish be-tween pathogenic and non-pathogenic strains). Fifth, intervieweesnoted the inherent variability of sampling and testingmethods betweenagencies, which may impede data sharing.Together, these five concerns emphasize ongoing challenges foragencies engaged in characterizing microbial risk. It is clear across therange of agencies interviewed that legislated indicators alone are insuf-ficient for assessment and microbial risk management needs and assuch, additional microbial tests are being applied. Interviewees empha-sized a desire for microbial tests with quicker turn-around-times andthat answered specific risk associated questions (e.g. whether a micro-organism is pathogenic to humans or whether groundwater is vulnera-ble to pathogen intrusion).4.2. Limited and variable use of risk assessmentRisk assessment practices across the 18 agencies interviewed arelimited and variable in terms of type of methods used, scope of applica-tion and frequency of use.4.2.1. Types of risk assessment methods usedAmong our case study agencies there appears to be limited up-take of the established formalized methods as identified inTable 1. In some cases, interviewees reported little awareness ofsuch tools. Of the methods and tools identified in Table 1, HACCP& CCP were the most commonly identified or familiar to our inter-viewees; however, the full implementation of these methods is lim-ited. Instead, interviewees indicated they typically use existingtools informally; drawing on elements of these tools (particularlyHACCP) to develop their own tailor-made risk assessment bettersuited to their needs or resource capacities (financial and staff). In-terviewees in both provinces identified a number of constraints totheir ability to practice microbial risk assessment and management.These include: insufficient data collection to “do justice to a risk as-sessment”; financial and staff capacity (to collect more data morefrequently, conduct specific microbial risk assessment projects orto introduce an industry standardized tools such as HACCP or ISOcertification); limited regulatory requirements (e.g. there are noregulated standards for Cryptosporidium); and lack of tools (e.g. toassess microbial risks to groundwater).Only two of the 18 agencies (both in Ontario) use QMRA routine-ly. One application is by a health authority for beach (recreational)water quality purposes and the other is by a water utility. Both agen-cies acknowledged the technical support provided by Health Canadain their implementation of QMRA. One Ontario water utility inter-viewee indicated that the absence of provincial funding limited thecapacity of practitioners to use QMRA; instead collaboration with549G. Dunn et al. / Science of the Total Environment 468–469 (2014) 544–552academic researchers was driving its use in municipalities. Two wa-tershed agencies (both in BC) conduct ecological or environmentalrisk assessments: one includes microbial water quality data andthe other focuses only on chemical risk. Challenges to conduct eco-logical risk assessments on a watershed scale identified by the inter-viewees (mentioned in Sections 4.1.2 and 4.1.3) are found in theliterature (Serveiss and Ohlson, 2007).4.2.2. Scope and frequency of applicationRisk assessments that are formalized, routine and applied system-wide have not been widely adopted by the agencies interviewed,other than the Ontario water utilities, which conduct these fromsource-to-tap. The most common applications of risk assessments areshort-term or one-off assessments. For example, prior to design andconstruction of a water treatment plant or a project specific assessmentmight be undertaken to examine oneparticular component of the entirewater system (e.g. recreational water quality at a certain beach, or untilengineering controls for a specific contamination source could beestablished). No one reported using any of these models explicitly forecosystem health.4.3. Limited use of risk management plansTen interviewees noted that their agency does not have any formalrisk management plan in place for human health or ecosystem pur-poses, including all six watershed authorities in BC and Ontario. Asone BC water utility interviewee observed, “…from the point thewater enters the intake, down to the customer's tap, we do not have ariskmanagement process. Not an explicit one certainly.”Of the agenciesthat stated they do have a risk management plan the extent of thesewere varied and often project specific (e.g. requirement for filtration de-ferral). Only one agency identified having ever used a specific microbialrisk management plan, for groundwater under direct influence of sur-face water; however, the interviewee noted that they no longer usethis method.While many of the interviewees acknowledged their agency doesnot have a formalized risk management plan for microbial risk, allwater utilities and health authorities have a formal Emergency Re-sponse Procedure (ERP), which is a regulatory requirement in both BCand Ontario. These procedures are activated once an actual (e.g. E. colipresent in treated water) or perceived (e.g. elevated total coliformcount or turbiditymeasurement)microbial contamination event occursand typically includes a communication strategy. In line with this find-ing, a few interviewees suggested that their current approach to risk as-sessment or management is reactive.Interestingly, despite the absence of microbial risk assessment prac-tices, there is general confidence among the agencies interviewed (13out of the 18 interviewees) that they arewell positioned to handle ami-crobial contamination event. This confidence could be attributed to avariety of factors including: i) having formalized response and commu-nication procedures in place (some municipalities have designated cri-sis management teams); ii) routine monitoring at least at the tap(continuous monitoring in the water treatment plant or compliancemonitoring as required by legislation); iii) land ownership aroundsource waters (particularly the ability to exert control over sourcewater protection); iv) system knowledge (such as lessons learnedfrom previous incidents); and v) having a contingency plan in place toaugment their water supply.4.4. Differing provincial approaches to risk assessment and riskmanagementOntario and BC have fundamentally different governance approachesto the application risk assessment and management (see Table 3).Ontario legislation requires that operators of municipal water sys-tems conduct microbial risk assessments and all three of the Ontariowater utilities interviewed confirmed they conduct formal microbialrisk assessment in accordance with the Ontario's Safe Drinking WaterAct 2002s.15(1). This legislation requires municipal drinkingwater sys-tems operators to prepare operational plans according to the Director'sdirections. The directions prescribe a Drinking Water Quality Manage-ment System (DWQMS) specifying minimum requirements for risk as-sessment and risk management in operational plans (Schedule A). Asone Ontario water utility interviewee described, “It's a pretty legislatedregulatory environment that we function in.” Indeed, penalties for non-compliance are onerous; as of January 2013 water system owners andoperators in Ontario bear personal responsibility (financial penaltiesand/or imprisonment). In contrast, BC has no legislative imperative; adrinking water officer may require a BC water utility to undertake butthis is discretionary. Only one of the three BCwater utilities interviewedacknowledged using a formalized risk assessment andmanagement ap-proach, whichwas a requirement to obtain a filtration deferral forwatertreatment. None of the BC water utilities undertakes formal microbialrisk assessment ormanagement on a routine basis. One interviewee ob-served, “the expectations [in BC] are not as high [in comparison withOntario], so they are not difficult to meet. In terms of drinking waterhealth, in most other jurisdictions… there is more stringent manage-ment within the regulation.”Given the small sample size, we can only suggest that indeed theregulatory differences between the twoprovinces appear to have an im-portant impact in terms of themicrobial risk practices being undertakenby these agencies. We discuss these key provincial differences inSection 5.1.5. DiscussionThere are several axes of variability that emerged as important in theanalysis: 1) approaches to microbial risk assessment and managementare variable between provinces; 2) water utilities, health authoritiesand watershed authorities approach, and may be required to approach,risk assessment and management differently; 3) risk assessment andmanagement practices (particularly in BC) diverge from the literatureon best practices in ways that are potentially significant; 4) there is lim-ited, if any, focus on risk assessment for ecosystem health from the mi-crobial perspective and 5) testing method limitations.5.1. Varying approaches between provincesBritish Columbia andOntario have notably differentwater governanceframeworks. In response to recommendations in the Walkerton Inquiry(O' Connor, 2002), Ontario overhauled their water governance approach.A strong legislative and regulatory framework was introduced with asource-to-tap focus, and includes risk management protocols to enforceand harmonize approaches across the province (Jayarante, 2008; O'Connor, 2002). Specifically, Ontario is the first province in Canada to in-troduce a legislated, semi-quantitative risk assessment framework forsource water protection. As one Ontario water utility interviewee de-scribed, “Wehave amulti-barrier approach and in fact it is nowenshrinedin legislation”.In contrast, legislated requirements in BC are narrower in scope; theBC approach to source protection might best be described as voluntary(see part 5 of the BC DWPA). Moreover, the BC DWPA and its regulations(see Table 3) are outcome-based in that they specify the outcomes to beachieved, not how to achieve them. BC does have provincial guidelinesfor the multi-barrier approach, but none explicitly for risk assessmentand risk management. Some BC interviewees attributed confidence intheir water quality to their ability to protect their source water (eitherthrough limited land use activity or fully protected watersheds). Indeed,BC's topography lends itself more easily to source protection with ap-proximately 60% of the province's population receiving water fromprotected watersheds (including the cities of Vancouver and Victoria).However, despite the fact that fully protected watersheds serve more550 G. Dunn et al. / Science of the Total Environment 468–469 (2014) 544–552than half the population, BC has the highest number of boil water advi-sories per capita (Eggerston, 2008). Furthermore, the province has alsohad the highest rate of enteric (gastrointestinal) infections of all theCanadian provinces, a proportion of whichmay be attributable to water-borne transmission (Isaac-Renton et al., 2003). Historically, BC watersupplies have not always been safe and highlight that a perception ofpristine water province-wide may actually undermine risk managementto the extent that this perceptionmay contribute to the lack of preventa-tive practices.5.2. Varying approaches between watersheds and similar agenciesFew clear patterns emerge in terms of type, methods, scope and fre-quency of risk assessment and management between agencies withsimilar mandates. Our results show that in our two case provinces, be-tween watersheds and between agencies (even of the same type) riskassessment and management practices vary widely. While watershedauthorities typically focus on overall watershed characterization and as-sessment (using environmental, ecological or regional risk assessmenttools, but not always includingmicrobial pathogens), health authoritiesand water utilities focus primarily on drinking water supply using TQMbased tools, which incorporate elements of HACCP and CCP. Not onlydoes the scope and frequency of microbial risk assessment vary but sodo the methods applied. No single tool has been adopted widely. Agen-cies that do practice risk assessment often prefer to develop their owntools. None of the agencies studied have pursued formal certification(e.g. ISO 9001 and 14001), citing limited capacity (financial and staff)as an impediment.5.3. Limited focus on ecosystem healthThere is limited evidence in the literature that ecosystem-focused risk assessments are routinely incorporated into water riskassessment and management activities (Pollard and Huxham,1998). Serveiss and Ohlson (2007) argue that in Canada water qual-ity standards are human-centric and watershed planning is orientedtoward drinking water quality protection, focusing primarily onchemical and physical measures, omitting a broader ecosystem per-spective. A truly integrated source-to-tap risk management ap-proach should emphasize both human and ecosystem health. Theconcept of integrating human and ecological risk assessment hasbeen advocated in the environmental literature (Harvey et al.,1995; Sekizawa and Tanabe, 2005; Scott et al., 2005) but only ap-plied infrequently to aquatic environments (Moiseenko et al.,2006; Orme-Zavaleta and Munns, 2008; Wang, 2006). Moreover, inthe literature, ecological risk assessments for aquatic environmentshave focused largely on chemical risk assessment, rather than mi-crobial risk assessment (Brock, 2013; Ellis, 2000; González-Pleiteret al., 2013; Leeuwangh et al., 1993). An integrated risk managementapproach is consistent with the “One Health” approach advocated byorganizations such as the WHO and the World Organization for An-imal Health: that environments, animals and humans health are in-terrelated in a complex system with many common stressors. Anintegrated approach allows for a broader, system-wide approach tomanaging microbial risks and creates efficiencies by using commonsets of tools for risk characterization, assessment and management.Consider the example of an algal bloom: algal toxins are harmful tomammals (human, aquatic and terrestrial mammals) and thebloom can also change nutrient and gas cycling in the ecosystemresulting in adverse outcomes at multiple trophic levels in the eco-system. Here, ecosystem and human health are clearly connectedand could benefit from an integrated approach.In our case study entities, we find ecosystem risk assessments arelargely absent and, when present, are not integratedwith human healthrisk assessments. Even in large water utilities, which have both water-shed and drinking water departments, we found little integration ofecosystem and human health assessments, and minimal emphasis onthe microbial dimensions of ecosystem health in general. Even withinthe same organization, different tools are being used in ways that canserve as an obstacle to integration. One interviewee from BC postulatedthat ecosystem health is on the whole poorly understood. He observed,“one of the biggest problems I think we have is the assumption that wecan treat something, therefore, we don't have to worry so much aboutthe quality of the source. I think there needs to be a strong connectionbetween the quality of the source and what's coming out the pipe. Idon't think that we want to promote the notion that we can — weshould allow the degradation of the source simply by increasing thetreatment. So an emphasis on watershed planning, on controllingnon-point sources, on people knowinghow their actions affect the qual-ity of the source and how that relays into cost savings in terms oftreatment.”5.4. Divergence from literature on best practiceOn thewhole, our research also indicates that current approaches tomicrobial risk assessment and management in BC case study sites, andto a lesser degree in Ontario, remain largely reactive. Formal microbialrisk assessment and management practices are not widely adoptedacross agencies; they are not typically carried out on a continuousbasis (but rather on an ad hoc, as needed basis); and they are not carriedout across the full water system from source to tap, rather componentsof the system (e.g. focusing only on the treatment dimensions, ratherthan incorporating quality of source water as well). Evidencing a reac-tive risk management pattern, agencies indicated that risk assessmentsare typically instigated after a contamination event. While ERPs have anessential role, these are best thought of as reactive approaches. Abroader proactive approach as advocated by the WHO would requiremicrobial hazard identification and efforts to prevent and remediatecontamination events. We find that in BC in particularmicrobial risk as-sessment and management approaches for water quality have not yetachieved the vision of the WHO. Internationally and in Canada, despitethe emphasis on source protection, ecosystem health appears to be alower priority. Economic and political factors; assumptions made isrisk assessment scenarios; and other factors can enable or constrainmi-crobial risk assessment and management practices (see Reimann andBanks, 2004). Furtherwork onwhymicrobial riskmight not be pursued,or complex tradeoffswith other human and ecosystem health consider-ations would be a fruitful avenue for future exploration.We postulate that the regulatory context in Ontario is having someimpact on actual practices of risk assessment and management. Al-though not as extensively as we might expect to be able to more ade-quately integrate human and ecosystem approaches, or to share dataacross agencies. In terms of other important trajectories toward theadoption of more integrated and explicit approaches, it is also worthnoting that the Canadian province of Alberta is introducing a legal re-quirement for drinking water safety plans by December 2013; butagain, this will likely focus on human health rather than an integratedrisk management approach.5.5. Limitations of current testing methodologiesThe success of microbial risk assessment andmanagement is only asgood as the available risk characterization or measurement tools. In ad-dition to identifying gaps in current approaches to risk assessment andmanagement, our research highlights key limitations to current micro-bial testingmethods, a critical first step in risk assessment andmanage-ment. As discussed in Section 4.1.3, interviewees were most concernedwith the turn-around-times and suitability of current tools to enablecomprehensive and routine microbial risk assessment. While all micro-bial classes (bacteria, protozoa and viruses) are harmful to ecosystemand human health, most of the available tools are narrow in range,targeting only bacterial pathogens (Davison et al., 2005). As noted,of microbial drinking water quality testing in three Canadian provinces. Can WaterResour J 2013. http://dx.doi.org/10.1080/07011784.2013.822186 [in press, acceptedCan Med Assoc J 2008;178(10):1261–3.Ellis JB. Risk assessment approaches for ecosystem responses to transient pollution events551G. Dunn et al. / Science of the Total Environment 468–469 (2014) 544–552some interviewees identified the need for additional testing parametersto enable thorough risk assessment and risk management.Developments in genomics and biotechnology may resolve some ofthe methodological limitations to risk characterization identified by in-terviewees. For example, water metagenomics studies may identifynew targets formicrobial testing, whichmay allow risk characterizationalong a wider, and more representative, set of microbial parameters(Thomas et al., 2012; Languille et al., 2012). Current risk characteriza-tion approaches rely on detection of microbial indicators, which donot accurately predict the occurrence of all bacterial, viral and protozo-an pathogen, while pathogen specific testing is cost prohibitive and lackthe sensitivity required for adequate risk characterization. Novelmarkers that could better predict the occurrence of bacterial, viral andprotozoan pathogenswould improve risk assessment andmanagementactivities.Furthermore, biotechnology advancements in testing platforms willlikely allow more sensitive assays (lower limits of detection), fasterturn-around-times, identification of contamination source, and areexpected to be available in the near future at equal or lower costs. For ex-ample, quantitative real-time polymerase chain reaction (qPCR), whichdetects the nucleic acid of a microorganism rather than culturing organ-isms, provides the benefit of being able to detect even organisms thatcannot easily be cultured such as viruses, protozoa and some difficultto culture bacteria. This platform can test nearly any microbial target, isflexible (new assays can easily be developed) and is widely applied inclinical diagnostics. We see considerable potential for new markers onnew qPCR platforms to be integrated into current risk assessment andmanagement approaches. Novel tests that aremore sensitive and specif-ic have the potential to significantly improve microbial risk assessmentand management capacities. It should be noted, however, that nucleicacid based approaches like qPCR do have methodological limitations,such as challenges with compounds that may inhibit the assay or detec-tion of dead cells. Technical advancements have addressedmanyof thesetechnical challenges and are detailed by others (Girones et al., 2010; Awand Rose, 2012).6. ConclusionsIn sum, our research identifies considerable variability in risk assess-ment and management frameworks currently applied in BC and Ontar-io. We find that the variability between andwithin provinces, as well asbetween agencies, is indicative of an overall lack of a uniform approach.We find that the most common applications of risk assessments areshort-term or one-off assessments. Risk assessments that are formal-ized, routine (or continuous) and applied system-wide (i.e. the entirewater supply system — source-to-tap) have not been adopted widely.Our findings of varied approaches between and within provinces arebroadly consistent with the literature on water governance in Canada,which indicates considerable fragmentation, and that water manage-ment is often ad hoc (Bakker and Cook, 2011; Hill et al., 2008; Hrudey,2011; Weibust, 2009). We also observe that ecological risk assessmentis largely absent among the entities interviewed. Our research suggeststhat current approaches to microbial water quality are still largely im-plicit and reactive, diverging from the literature on best practices inthe water sector.The literature suggests the need for preventative and explicit riskmanagement for the protection of both human and ecosystem health,but our case study provinces fail tomeet these best practices in a compre-hensivemanner. In termsof significance, thisworkhighlights the need forimproved microbial risk assessment and management frameworks inCanada. At a minimum, data needs to be comparable and integrated,and resources and expertise need to be shared in order to overcomesome of the issues identified by interviewees. Adoption of improved mi-crobial testing, based on genomics and biotechnological advances,would provide richer data, faster, and improve risk assessment andman-agement. Aswell, we see considerable scope tomore adequately evaluatein urban receiving waters. Chemosphere 2000;41(1–2):85–91.Gelting R. Water safety plans: CDC's role. J Environ Health 2009;72(4):44–5.Girones R, Ferrús MA, Alonso JL, Rodriguez-Manzano J, Calgua B, Corrêa Ade A, et al. Mo-lecular detection of pathogens in water—the pros and cons of molecular techniques.Water Res 2010;44(15):4325–39. [Aug].González-Pleiter M, Gonzalo S, Rodea-Palomares I, Leganés F, Rosal R, Boltes K, et al. Tox-icity of five antibiotics and their mixtures towards photosynthetic aquatic organisms:July].Cool G, Rodriguez MJ, Bouchard C, Levallois P, Joerin F. Evaluation of the vulnerability tocontamination of drinkingwater systems for rural regions in Quebec, Canada. J EnvironPlan Manag 2010;53(5):615–38.Davies JM, Mazumder A. Health and environmental policy issues in Canada: the role ofwatershedmanagement in sustaining clean drinking water quality at surface sources.J Environ Manage 2003;68:273–86.Davison A, Howard G, Stevens M, Callan P, Fewtrell L, Deere D, et al. Water safety plans:managing drinking-water quality from catchment to consumer. Prepared fortheGeneva: World Health Organisation; 2005 [WHO/SDE/WSH/05.06].Dominguez-Chicas A, Scrimshaw MD. Hazard and risk assessment for indirect potablereuse schemes: an approach for use in developing water safety plans. Water Res2010;44(2):6115–23.Egerton AJ. Achieving reliable and cost effective water treatment. Water Sci Technol1996;33(2):143–9.Eggerston L. Investigative report: 1766 boil-water advisories now in place across Canada.the importance of different regulatory frameworks, either in terms ofactual risk management practices, or better still, linkages to humanand ecosystem health outcomes. In the absence of considerable progresstoward these ends, human and ecosystem health may continue to becompromised.AcknowledgmentsThis research was conducted as a part of a three-year (2011–2014)project Applied Metagenomics of the Watershed Microbiome. Theauthors would like to thank Genome British Columbia and GenomeCanada for financially supporting this research. Thank you also to theCanadian Water Network and the Alberman Fellowship at theHebrew University of Jerusalem for additional financial support. Formore information about this project, please visit our website www.watersheddiscovery.ca. The authors would particularly like to acknowl-edge the contributions from research team members Judy Isaac-Renton,Karen Bakker, Ida Ngueng Feze, Beverly Holmes and Maggie Low.ReferencesAshbolt NJ. Risk analysis of drinking water microbial contamination versus disinfectionby-products (DBP's). Toxicology 2004;198(1–3):255–62.Ashbolt NJ, SchoenME, Soller JA, Roser DJ. Predicting pathogen risks to aid beachmanage-ment: the real value of quantitative microbial risk assessment (QMRA). Water Res2010;44:4692–703.Austin Z, AlcockRE, ChristleyRM,Haygarth PM,HeathwaiteAL, LathamSM, et al. Policy, prac-tice and decisionmaking for zoonotic disease management: water and Cryptosporidium.Environ Int 2012;40:70–8.Aw TG, Rose JB. Detection of pathogens in water: from phylochips to qPCR topyrosequencing. Curr Opin Biotechnol 2012;23(3):422–30.Bakker K, Cook C. Water governance in Canada: innovation in the context of fragmenta-tion. Int J Water Resour Dev 2011;27(2):275–89.Bartram J, Corrales L, Davison A, Deere D, Drury D, Gordon B, et al. Water safety planman-ual: step-by-step risk management for drinking-water suppliers. Geneva: WorldHealth Organization; 2009.Benke KK, Hamilton AJ. Quantitativemicrobial risk assessment: uncertainty andmeasuresof central tendency for skewed distributions. Stoch Environ Res Risk Assess2008;22(4):533–9.British Columbia Drinking Water Protection Act (BC DWPA), Drinking Water ProtectionRegulation B.C. Reg. 200/2003. O.C. 508/2003.Brock TC. Priorities to improve the ecological risk assessment and management for pesti-cides in surface water. Integr Environ Assess Manag 2013;9(3):e64–74. [Apr 22].Byleveld PM, Deere D, Davison A. Water safety plans: planning for adverse events andcommunicating with consumers. J Water Health 2008;6:1–9.Canadian Council of Ministers of the Environment (CCME). From source to tap: guidanceon the multi-barrier approach to safe drinking water. Ottawa, Ontario: CanadianCouncil of Ministers of the Environment Water Quality Task Group and the Feder-al–Provincial–Territorial Committee on Drinking Water; 2004.Cook C, Prystajecky N, Ngueng Feze I, Joly Y, Dunn G, Kirby E, et al. A comparative analysisimplications for environmental risk assessment. Water Res 2013;47(6):2050–64.Goss M, Richards C. Development of a risk-based index for source water protection plan-ning, which supports the reduction of pathogens from agricultural activity enteringwater resources. J Environ Manage 2008;87(4):623–32.Gozlan RE, Peeler EJ, LongshawM, St-Hilaire S, Feist SW. Effect of microbial pathogens onthe diversity of aquatic populations, notably in Europe. Microbes Infect 2006;8(5):1358–64.Gunnarsdottir MJ, Gardarsson SM, Elliott M, Sigmundsdottir G, Bartram J. Benefits ofwater safety plans: microbiology, compliance, and public health. Environ Sci Technol2012;46(14):7782–9.Haas CN, Rose JB, Gerba CP. Quantitative microbial risk assessment. New York: Wiley;1999464.Hamilton P, Gale P, Pollard SJT. A commentary on recent water safety initiatives in thecontext of water utility risk management. Environ Int 2006;32:958–66.Harvey T, Mahaffey KR, Velazquez S, Dourson M. Holistic risk assessment: an emergingprocess for environmental decisions. Reg Toxicol Pharmacol 1995;22:110–7.Harwood VJ, Levine AD, Scott TM, Chivukula V, Lukasik J, Farrah SR, et al. Validity of theindicator organism paradigm for pathogen reduction in reclaimed water and publichealth protection. Appl Environ Microbiol 2005;71:3163–70.Hill C, Furlong K, Bakker K, Cohen C. Harmonization versus subsidiarity in water gover-strategies: the case of long-term human impacts on an Arctic lake. Sci Total Environ2006;369(1–3):1–20.Ngueng Feze I, Kirby E, PrystajeckyN, CookC, Knoppers BM,Ozdenmir V, et al. Legal analysisof water quality assessment biotechnologies: is Canada ready to ride the next wave ofmetagenomics testing? Ott Law Rev 2013w. [under review, submitted March].O' Connor DR. Part two. Report of theWalkerton Inquiry. A strategy for safe water. Ottawa:Ministry of the Attorney General; 2002. p. 582.Orme-Zavaleta J, Munns Jr WR. Integrating human and ecological risk assessment: appli-cation to the cyanobacterial harmful algal bloom problem. Adv Exp Med Biol2008;619:867–83.Phillips JD. Nonpoint source pollution and spatial aspects of risk assessment. Ann AssocAm Geogr 1988;78(4):611–23.Pollard P, Huxham M. The European Water Framework Directive: a new era in the man-agement of aquatic ecosystem health? Aquat Conserv 1998;8(6):773–92.Pollard SJT, Strutt JE, MacGillivary BH, Hamilton PD, Hrudey SE. Risk analysis in the waterutility sector: a review of drivers, tools and techniques. Process Saf Environ Prot2004;82(B6):453–62.Reimann C, Banks D. Setting action levels for drinking water: are we protecting our healthor our economy (or our backs!)? Sci Total Environ 2004;322:13–21.Schijven JF, Teunis RF, Rutjes SA, Bouwknegt M, de Roda Husman AM. QMRAspot: a tool552 G. Dunn et al. / Science of the Total Environment 468–469 (2014) 544–552territories. Can Water Resour J 2008;33(4):1–18.Hrudey SE. Drinking water risk management principles for a total quality managementframework. In: Hrudey SE, editor. Drinkingwater safety— a total qualitymanagementapproach. NERAM, Institute for Risk Research, University of Waterloo; 2003. p. 3–14.Hrudey SE. Drinking water risk management principles for a total quality managementframework. J Toxicol Environ Health A 2004;67:1555–66.Hrudey SE. Chlorination disinfection by-products, public health risk tradeoffs and me.Water Res 2009;43:2057–92.Hrudey SE. Safe drinking water policy in Canada — turning hindsight into foresight. C.DHowe Institute commentary: the water series no. 323Toronto: CD Howe Institute;2011.Hrudey SE, Hrudey EJ, Pollard SJT. Risk management for assuring safe drinking water.Environ Int 2006;32:948–57.Hunter PR, Payment P, Ashbolt N, Bartram J. Chapter 3— assessment of risk. Assessingmi-crobial safety of drinking water: improving approaches and methods. Published onbehalf of World Health Organization and organization for economic co-operationand development. London: IWA Publishing; 2003. p. 79–109.Isaac-Renton JIR, Peck S, Kendal P. Health drinking water in British Columbia: a physi-cians' update. B C Med J 2003;45(9):436.Ivey JL, de Loë RC, Kreutzwiser RD. Planning for source water protection in Ontario. ApplGeogr 2006;26:192–209.Jayarante A. Application of a risk management system to improve drinking water safety.J Water Health 2008;6(4):547–57.Krewski D, Balbus J, Butler-Jones D, Haas C, Isaac-Renton JIR, Roberts KJ, et al. Managinghealth risks from drinkingwater—a report to theWalkerton inquiry. J Toxicol EnvironHealth A 2002;65(21):1635–823.Languille MGI, Laird MR, HsiaoWWL, Chiu TA, Eisen JA, Brinkman FSL. MicrobeDB: a locallymaintainable database of microbial genomic sequences. Bioinformatics 2012;28(14):1947–8.Leclerc H, Mossel DAA, Edberg SC, Struijk CB. Advances in the bacteriology of the coliformgroup: their suitability as markers of microbial water safety. Annu Rev Microbiol2001;55:201–34.Leeuwangh P, Brock TC, Kersting K. An evaluation of four types of freshwater model eco-system for assessing the hazard of pesticides. Hum Exp Toxicol 1993;13(12):888–99.Miller MA, Gardner IA, Kreuder C, Paradies DM, Worcester KR, Jessup DA, et al. Coastalfreshwater runoff is a risk factor for Toxoplasma gondii infection of southern sea otters(Enhydra lutris nereis). Int J Parasitol 2002;32(8):997–1006.Miller R, Whitehill B, Deere D. A national approach to risk assessment for drinking watercatchments in Australia. 4thWorldWater Congress. Water SupplyWater Serv Manag2005;5(2):123–34.Miller KM, Li S, Kaukinen KH, Ginther N, Hammill E, Curtis JM, et al. Genomic signatures pre-dictmigration and spawning failure inwild Canadian salmon. Science 2011;331(6014):214–7.Moiseenko TI, Voinov AA, Megorsky VV, Gashkina NA, Kudriavtseva LP, Vandish OI, et al.Ecosystem and human health assessment to define environmental managementfor quantitative microbial risk assessment from surface water to potable water.Water Res 2011;45(17):5564–76.Scott MJ, Brandt CA, Bunn AL, Engel DW, Eslinger PW, Miley TB, et al. Modeling long-termrisk to environmental and human systems at the Hanford Nuclear Reservation: scopeand findings from the initial model. Environ Manage 2005;35(1):84–98.Sekizawa J, Tanabe S. A comparison between integrated risk assessment and classicalhealth/environmental assessment: emerging beneficial properties. Toxicol ApplPharmacol 2005;207(2 Suppl.):617–22.Serveiss VB, Ohlson DW. Using ecological risk assessment principles in a Source WaterProtection Assessment. Hum Ecol Risk Assess 2007;13:402–17.Signor RS, Ashbolt NJ. Pathogen monitoring offers questionable protection against drink-ing water risks: a QMRA (quantitative microbial risk analysis) approach to assessmanagement strategies. Water Sci Technol 2006;54(3):261–8.Smeets PW, Rietveld LC, van Dijk JC, Medema GJ. Practical applications of quantitativemi-crobial risk assessment (QMRA) forwater safety plans.Water Sci Technol 2010;61(6):1561–658.Summerill C, Smith J, Webster J, Pollard SJT. An international review of the challenges as-sociated with securing buy-in for water safety plans within providers of drinkingwater supplies. J Water Health 2010a;8(2):387–98. [http://www.iwaponline.com/jwh/008/jwh0080387.htm].Summerill C, Pollard SJT, Smith JA. The role of organizational culture and leadership inwater safety plan implementation for improved risk management. Sci Total Environ2010b:4319–27.Summerscales IM, McBean EA. Application of risk assessment tools to small drinkingwater systems in British Columbia. Water Qual Res J Can 2011;46(4):332–44.Taylor CM, Pollard SJT, Angus AJ, Rocks SA. Better by design: rethinking interventions forbetter environmental regulation. Sci Total Environ 2013;408(20):488–99.Thomas T, Gilbert J, Meyer F. Metagenomics — a guide from sampling to data analysis.Microb Inform Exp 2012;2(1):3.Vieria JMP. Water safety plans: methodologies for risk assessment and risk managementin drinking water systems. Water in Celtic countries: quantity, quality and climatevariability 2007;310:57–67.Wang M. Optimal environmental management strategy and implementation for ground-water contamination prevention and restoration. Environ Manage 2006;37(4):553–66.Weibust I. The green leviathan: the case for a federal role in environmental policy. Alder-shot: Ashgate Publishing; 2009.Weitz JS, Wilhelm SW. Ocean viruses and their effects onmicrobial communities and bio-geochemical cycles. F1000 Biol Rep 2012;4:17.World Health Organization. Guidelines for drinking-water quality. Recommendations,3rd ed., vol. 1. Geneva: World Health Organization; 2004.Yin RK. Applications of case study research. 2nd ed. Sage Publications; 2003.Yokoi H, Embutsu I, Yoda M, Waseda K. Study on the introduction of hazard analysis andcritical control point (HACCP) concept of the water quality management in watersupply systems. Water Sci Technol 2006;53(4):483–92.nance: a review of water governance and legislation in the Canadian provinces and


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