| #Q001 | treatment | health | recommended | Treatment and Protection Implementation | drinking water | Treatment technologies and watershed or wellhead protection measures known to reduce the risk of waterborne illness should be implemented and maintained if source water is subject to faecal contamination or if enteric viruses have been responsible for past waterborne outbreaks. | if source water is subject to faecal contamination or if enteric viruses have been responsible for past waterborne outbreaks | high |
| #Q002 | administrative | operational | recommended | Risk Management Approach | drinking water | Exposure to viruses should be reduced by implementing a risk management approach to drinking water systems, such as the multiple barrier or water safety plan approach. | | high |
| #Q003 | administrative | operational | mandatory | System Assessment Content | drinking water | These approaches require a system assessment that involves: characterizing the water source; describing the treatment barriers that prevent or reduce contamination; highlighting the conditions that can result in contamination; and identifying control measure to mitigate those risks through the treatment and distribution systems to the consumer. | | high |
| #Q004 | administrative | operational | recommended | Routine Source Water Assessments | drinking water | Source water assessments should be part of routine system assessments. | | high |
| #Q005 | monitoring | health | recommended | Source Water Assessment Elements | drinking water | They should include: the identification of potential sources of faecal contamination in the watershed/aquifer; potential pathways and/or events (low to high risk) by which enteric viruses can make their way into the source water; and the conditions that are likely to lead to peak concentrations of enteric viruses. | | high |
| #Q006 | monitoring | health | recommended | Subsurface Source Evaluation | drinking water | Subsurface sources should be evaluated to determine if the supply is vulnerable to contamination by enteric protozoa (i.e., GUDI) and enteric viruses. | | high |
| #Q007 | monitoring | health | recommended | Assessment Procedures | drinking water | These assessments should ideally include a hydrogeological assessment and, at a minimum, an evaluation of well integrity and a survey of activities and physical features in the area. | | high |
| #Q008 | monitoring | reporting | recommended | Virus Monitoring Characteristics | drinking water | When monitoring for viruses, the viability and infectivity of viruses should be determined, as well as the recovery efficiency of the method used. | When monitoring for viruses | high |
| #Q009 | monitoring | health | recommended | Surface Water Sampling Frequency | drinking water | For surface water, it is recommended to conduct monthly sampling through all four seasons to establish baseline levels and to characterize at least two weather events to understand peak conditions | For surface water | high |
| #Q010 | monitoring | health | guidance | Intensified Surface Water Sampling | drinking water | due to the temporal variability of viruses in surface water, intensified sampling (i.e., five samples per week) may be necessary to quantify peak concentrations. | during peak contamination events in surface water | high |
| #Q011 | monitoring | health | recommended | Groundwater Sampling Frequency | drinking water | For groundwater, including confined aquifers... Monthly sampling through all four seasons is recommended to adequately characterize the occurrence of viral contamination. | For groundwater | high |
| #Q012 | treatment | treatment | recommended | Treatment Fluctuation Consideration | drinking water | The appropriate type and level of treatment should take into account potential fluctuations in water quality, including short-term degradation, and variability in treatment performance. | | high |
| #Q013 | monitoring | health | recommended | Private Well Vulnerability Assessment | drinking water | Individual households with a well should assess the vulnerability of their well to faecal contamination to determine if their well should be treated. | Individual households with a well | high |
| #Q014 | operational | operational | recommended | Distribution System Maintenance | drinking water | Distribution system water quality should be regularly monitored (e.g., microbial indicators, disinfectant residual, turbidity, pH), operations/maintenance programs should be in place (e.g., water main cleaning, cross-connection control, asset management) and strict hygiene should be practiced during all water main construction (e.g., repair, maintenance, new installation) to ensure drinking water is transported to the consumer with minimum loss of quality. | | high |
| #Q015 | operational | health | recommended | Source Water Protection Implementation | drinking water | Source water protection measures to minimize faecal contamination, especially control of sanitary sewage, should be implemented where feasible. | where feasible | high |
| #Q016 | operational | operational | mandatory | Operator Training | drinking water | Operator training is also required to ensure the effective operation of treatment barriers at all times (Smeets et al., 2009). | | high |
| #Q017 | treatment | health | mandatory | Treatment Goal Fulfillment Before Distribution | drinking water | It is essential that treatment goals be achieved prior to the first consumer in the distribution system. | | high |
| #Q018 | monitoring | treatment | recommended | Site-Specific Assessment of Treatment Efficacy | drinking water | Given the uncertainty associated with the use of log removal and log inactivation credits estimated from scientific literature, it is recommended that a site-specific assessment of treatment efficacy be conducted by each drinking water system (Smeets, 2011). | | high |
| #Q019 | monitoring | treatment | recommended | Source Water Characterization | drinking water | To determine the necessary level of treatment, source water should be adequately characterized. | | high |
| #Q020 | monitoring | health | recommended | Sampling-Based Enteric Virus Characterization | drinking water | Where possible, source water enteric virus concentrations should be characterized based on actual water sampling and analysis. | Where possible | high |
| #Q021 | monitoring | health | recommended | Event-Based Source Water Monitoring | drinking water | Such characterization should take into account normal conditions as well as event-based monitoring, such as spring runoff, storms or wastewater spill events. | | high |
| #Q022 | monitoring | reporting | recommended | Recovery Efficiency and Viability Considerations | drinking water | Sampling results should take into account recovery efficiencies for the analytical method and pathogen viability in order to obtain the most accurate assessment of infectious pathogens present in the source water | | high |
| #Q023 | treatment | health | recommended | Safety Factors and Additional Treatment | drinking water | engineering safety factors or additional treatment reductions should be applied in order to ensure production of microbiologically safe drinking water. | given the uncertainty of source water estimates | high |
| #Q024 | monitoring | health | recommended | Subsurface Vulnerability Evaluation | drinking water | Subsurface sources should be evaluated to determine whether the supply is vulnerable to contamination by enteric viruses and protozoa. | | high |
| #Q025 | operational | operational | mandatory | Filter Operation and Optimization | drinking water | filters must be carefully controlled, monitored and backwashed to optimize filter performance. | | high |
| #Q026 | operational | treatment | recommended | Filter Backwash Recirculation | drinking water | It is recommended that filter backwash water not be recirculated through the treatment plant without additional treatment | | high |
| #Q027 | operational | operational | recommended | Coagulation Optimization | drinking water | Jar tests should be conducted to optimize the coagulation process | | high |
| #Q028 | monitoring | treatment | recommended | Slow Sand Filtration Pilot Testing | drinking water | Pilot testing is recommended to ensure slow sand filtration will successfully treat source water | | high |
| #Q029 | monitoring | operational | recommended | Slow Sand Filtration Condition Monitoring | drinking water | the potential impacts of lower temperatures, increased hydraulic loading rates and filter scraping should be carefully monitored during filter operation. | | high |
| #Q030 | monitoring | operational | mandatory | Membrane Integrity Monitoring | drinking water | it is critical that regular monitoring of membrane integrity be conducted. | | high |
| #Q031 | operational | operational | mandatory | Membrane Backwashing and Cleaning | drinking water | Regular backwashing and periodic chemical cleaning, using proper foulant-based cleaning chemicals, is required to remove accumulated foulants. | | high |
| #Q032 | corrective_action | operational | mandatory | Membrane Replacement | drinking water | When the flux can no longer be restored to acceptable conditions, the membranes must be replaced | When the flux can no longer be restored to acceptable conditions | high |
| #Q033 | monitoring | health | recommended | Hydrogeological Assessment for Subsurface Sources | drinking water | Site-specific hydrogeological assessments are recommended to determine if subsurface sources are vulnerable to contamination by microbial pathogens. | | high |
| #Q034 | monitoring | health | recommended | Inventory of Faecal Sources and Subsurface Definition | drinking water | These assessments should, at a minimum, inventory faecal sources in the source water area (e.g., human and domestic animal waste, wildlife, recreational pressures) and define the subsurface (e.g., aquifer depth, protection zones, composition of the subsurface layers, preferential flow path conditions, rainfall risks). | | high |
| #Q035 | monitoring | operational | recommended | UV Reactor Validation Testing | drinking water | Validation testing should be conducted to determine the operating conditions under which the reactor will deliver the UV dose. | | high |
| #Q036 | monitoring | operational | recommended | UV Continuous Monitoring | drinking water | Continuous monitoring with regularly calibrated sensors should be conducted to verify that the unit remains within validated conditions and is delivering the required dose. | | high |
| #Q037 | operational | operational | recommended | UV Operational Issue Consideration | drinking water | Operational issues should also be considered to ensure performance is not compromised | | high |
| #Q038 | operational | operational | recommended | Optimum Filtration Upstream of UV | drinking water | utilities should strive to maintain optimum filtration conditions upstream of UV disinfection | | high |
| #Q039 | operational | operational | recommended | Hypochlorite Certification and Handling | drinking water | Supplies that use liquid chlorine as part of a multi-disinfectant strategy should use hypochlorite solutions that are certified as meeting NSF International (NSF)/American National Standards Institute (ANSI) standard 60 (NSF/ANSI, 2015a) and follow the handling and storage recommendations for hypochlorite outlined in (Health Canada (2015). | Supplies that use liquid chlorine as part of a multi-disinfectant strategy | high |
| #Q040 | operational | operational | recommended | Distribution System Maintenance and Operations | drinking water | Distribution system water quality should be regularly monitored (e.g., microbial indicators, disinfectant residual, turbidity, pH), operations/maintenance programs should be in place (e.g., water main cleaning, cross-connection control, asset management) and strict hygiene should be practiced during all water main construction, repair or maintenance to ensure drinking water is transported to the consumer with minimum loss of quality (Kirmeyer et al., 2001, 2014). | | high |
| #Q041 | monitoring | operational | recommended | Distribution System Pressure Monitoring | drinking water | Distribution system pressure monitoring is also recommended to optimize distribution system performance | | high |
| #Q042 | treatment | health | recommended | Semi-Public Groundwater Treatment | drinking water | small groundwater supplies providing drinking water to the public (i.e., semi-public systems) that are vulnerable to viral contamination should be treated to remove and/or inactivate enteric viruses. | small groundwater supplies providing drinking water to the public that are vulnerable to viral contamination | high |
| #Q043 | monitoring | health | recommended | Household Private Well Vulnerability Assessment | drinking water | In cases where an individual household obtains its drinking water from a private well, the vulnerability of the source to viral contamination should be assessed. | In cases where an individual household obtains its drinking water from a private well | high |
| #Q044 | monitoring | health | recommended | Private Well Bacteriological Testing | drinking water | Private well owners should regularly test (2-3 times per year) their well for bacteriological parameters (e.g., total coliforms and E. coli). | | high |
| #Q045 | prohibition | treatment | recommended | Prohibition of Point-of-Use Tech at Point-of-Entry | drinking water | Point-of-use technologies should not be installed at the point-of-entry as the treated water may be corrosive to internal plumbing components. | | high |
| #Q046 | monitoring | treatment | recommended | Periodic Device Verification Testing | drinking water | Periodic testing by an accredited laboratory should be conducted on both the water entering the treatment device and the finished water to verify that the treatment device is effective. | | high |
| #Q047 | operational | operational | recommended | Treatment Device Maintenance | drinking water | Treatment devices should be inspected and serviced in accordance with the maintenance schedule and manufacturer’s recommendations. | | high |
| #Q048 | operational | operational | mandatory | UV Lamp Cleaning and Replacement | drinking water | the regular cleaning and replacement of the lamp, according to manufacturer’s instructions, are critical in ensuring the proper functioning of the unit. | | high |
| #Q049 | operational | operational | recommended | Private Supply Hypochlorite Handling | drinking water | Private and semi-public supplies that use liquid chlorine should use hypochlorite solutions that are certified as meeting NSF/ANSI Standard 60 (NSF/ANSI, 2015a) and follow the handling and storage recommendations for hypochlorite outlined in (Health Canada (2015). | Private and semi-public supplies that use liquid chlorine | high |
| #Q050 | monitoring | health | recommended | Site-Specific Virus Reduction Assessment | drinking water | A site-specific assessment should be conducted to determine the level of virus reduction needed for a given source water. | | high |
| #Q051 | treatment | treatment | recommended | DBP Impact Consideration | drinking water | When selecting a chemical disinfectant, the potential impact of DBPs should be considered but it is essential that efforts made to minimize DBP formation, not compromise the effectiveness of disinfection. | When selecting a chemical disinfectant | high |
| #Q052 | monitoring | health | recommended | Well Owner System Knowledge | drinking water | When considering the potential for viral contamination specifically, well owners should have an understanding of the well construction, type of aquifer material surrounding the well and location of the well in relation to sources of faecal contamination (i.e., septic systems, sanitary sewers, animal waste, etc.). | When considering the potential for viral contamination specifically | high |
| #Q053 | administrative | treatment | recommended | Treatment Device Certification | drinking water | Health Canada does not recommend specific brands of drinking water treatment devices, but it strongly recommends that consumers look for a mark or label indicating that the device has been certified by an accredited certification body as meeting the appropriate NSF/ANSI standard. | When purchasing a treatment device | high |
| #Q054 | administrative | unknown | recommended | In-Situ Filtration Authority Consultation | drinking water | For in-situ filtration, the jurisdiction having authority should be consulted for site-specific requirements. | For in-situ filtration systems | high |
| #Q055 | monitoring | health | guidance | Indicator Monitoring Authority Requirement | drinking water | Monitoring of indicators/surrogates, such as E. coli or F-specific RNA bacteriophages, may be required by the responsible authority as part of the risk assessment (Mesquita and Emelko, 2015). | As part of the risk assessment for subsurface sources | high |
| #Q056 | operational | health | recommended | Watershed and Aquifer Protection | drinking water | Where possible, watersheds or aquifers that are used as sources of drinking water should be protected from faecal waste. | Where possible | high |
| #Q057 | operational | operational | recommended | Maintenance Component Longevity Verification | drinking water | Consumers should verify the expected longevity of the components in their treatment device according to the manufacturer’s recommendations and establish a clearly defined maintenance schedule. | For residential scale treatment systems | high |
| #Q058 | administrative | reporting | recommended | Jurisdictional Guidance Consultation | drinking water | Specific guidance related to the implementation of drinking water guidelines should be obtained from the appropriate drinking water authority in the affected jurisdiction. | | high |
| #Q059 | design | treatment | recommended | Treatment Process Identification and Pilot Testing | drinking water | Identification of the most appropriate treatment process requires site-specific evaluation and should be made after suitable analysis and/or pilot testing. | | high |
| #Q060 | monitoring | operational | guidance | Coagulation Monitoring of Net Surface Charge | drinking water | Monitoring the net surface charge of particles following coagulation may also be helpful where source water quality is highly variable (Conio et al., 2002; Newcombe and Dixon, 2006; AWWA, 2011b; Kundert, 2014; McVicar et al., 2015; Sharp, 2015). | where source water quality is highly variable | high |
| #Q061 | prohibition | health | recommended | Small System Surface Water Source Recommendation | drinking water | In general, surface water is not recommended as a private or semi-public water supply unless it is properly filtered, disinfected and monitored for water quality. | unless it is properly filtered, disinfected and monitored for water quality | high |
| #Q062 | treatment | health | guidance | GUDI Additional Treatment Guidance | drinking water | For GUDI sources, additional treatment may be needed to address other microbiological contaminants such as enteric protozoa. | For GUDI sources | high |
| #Q063 | administrative | operational | guidance | Jurisdictional Log Reduction Exception | drinking water | A jurisdiction may choose to allow a groundwater source to have less than the recommended minimum 4-log reduction if the assessment of the drinking water system has confirmed that the risk of enteric virus presence is minimal or the aquifer is providing adequate in-situ filtration. | If the assessment has confirmed that the risk of enteric virus presence is minimal or the aquifer is providing adequate in-situ filtration | high |
| #Q064 | monitoring | operational | mandatory | Water Sample Handling and Shipping | drinking water | Water samples are filtered in the field and then shipped on ice to a laboratory for processing as quickly as possible (ideally, within 24 hours). | During field sampling of raw water | high |
| #Q065 | monitoring | operational | recommended | Sample Volume Recommendation | drinking water | Current methods recommend filtering a few hundred litres of surface water, and 1,500 or more litres of groundwater (U.S. EPA, 2012; Cashdollar et al., 2013; Fout et al., 2015). | When collecting raw water samples for virus detection | high |
| #Q066 | monitoring | operational | recommended | Parallel Spiked Sample Processing | drinking water | It is generally recommended that spiked samples be processed in parallel with environmental samples, in order to better understand the true occurrence of viruses. | When conducting laboratory analysis for enteric viruses | high |
| #Q067 | monitoring | operational | recommended | Monitoring Program Design for Variability | drinking water | Monitoring programs should be designed with these factors in-mind in order to capture the variability that occurs in the water source (Dechesne and Soyeux, 2007). | When establishing monitoring programs for source water characterization | high |
| #Q068 | monitoring | operational | recommended | Uncertainty Analysis in Source Estimation | drinking water | In addition to monitoring, uncertainty analysis should also be used as a means to help evaluate the estimated source water concentrations (Petterson et al., 2015). | When estimating pathogen concentrations in source water for QMRA | high |
| #Q069 | treatment | health | recommended | Surface and GUDI Water Supply Treatment Requirements | drinking water | In general, all water supplies derived from surface water sources or groundwater under the direct influence of surface water (GUDI) should include adequate filtration (or equivalent technologies) and disinfection to meet treatment goals for enteric viruses and protozoa. | For water supplies derived from surface water or GUDI sources | high |
| #Q070 | monitoring | health | recommended | Groundwater Source Development Study Requirements | drinking water | The authors recommended that hydrogeologic and engineering studies conducted as part of groundwater source development collect sufficient information to identify and characterize high velocity preferential pathways through the aquitard. | As part of groundwater source development | high |
| #Q071 | monitoring | health | mandatory | Confined Aquitard Integrity Evaluation | drinking water | For confined aquifers, it is important that the integrity of the aquitard be evaluated (i.e., maximum depth of open fractures and thickness) and preferential pathways through the aquitard be identified and characterized (i.e., local, extensive with window, extensive with fractures or unfractured). | For confined aquifers | high |
| #Q072 | monitoring | health | recommended | QMRA Source Water Sampling Guidance | drinking water | Collecting and analysing source water samples for enteric viruses is, however, important for water utilities that wish to conduct a quantitative microbial risk assessment. | For water utilities wishing to conduct a QMRA | high |
| #Q073 | monitoring | health | recommended | Well Contamination Indicator Monitoring | drinking water | In particular, it is recommended that testing for parameters that can provide an indication that well water may be contaminated by a septic system or from surface water due to poor well integrity be conducted. | For assessment of household private well vulnerability | high |
| #Q074 | monitoring | health | guidance | Residential Nitrate and Chloride Testing | drinking water | Therefore, periodic testing of these parameters [nitrate and chloride] is useful for assessing if septic system effluent is impacting a well. | For private well owners to assess septic impact | high |
| #Q075 | treatment | health | recommended | GUDI Treatment Goal Compliance | drinking water | Sources determined to be vulnerable to enteric protozoa (i.e., GUDI) should meet the treatment goals for all pathogens (i.e., protozoa, bacteria and viruses), as outlined in the guideline technical document on enteric protozoa (Health Canada, 2012c). | Sources determined to be vulnerable to enteric protozoa (GUDI) | high |
| #Q076 | treatment | health | mandatory | Disinfection Efficacy Priority | drinking water | It is essential, however, that efforts made to minimize DBP formation not compromise the effectiveness of disinfection. | When selecting or operating chemical disinfection to minimize disinfection by-products | high |
| #Q077 | prohibition | health | guidance | NSF Class B Usage Restriction | drinking water | Class B systems are not intended for the disinfection of microbiologically unsafe water. | When selecting residential scale UV treatment systems | high |
| #Q078 | monitoring | operational | mandatory | Seasonal Raw Water Monitoring | drinking water | Monitoring of seasonal changes is also important to ensure that water utilities consistently produce high quality treated water for the full range of raw water conditions (Valade et al., 2009; Huck and Sozański, 2011). | To ensure consistent high quality production across all raw water conditions | high |
| #Q079 | administrative | reporting | recommended | Public Consultation Anonymity Statement | drinking water | Authors who do not want their name and affiliation shared with their CDW member should provide a statement to this effect along with their comments. | For authors submitting comments during the public consultation period | high |
| #Q080 | monitoring | operational | guidance | Virus Monitoring Sample Location | drinking water | Where monitoring for viruses is feasible, samples are generally collected at a location that is representative of the quality of the water supplying the drinking water system, such as at the intake of the water treatment plant or, in the case of groundwater, from each individual water supply well. | Where monitoring for viruses is feasible | high |
| #Q081 | treatment | operational | guidance | Pre-treatment Filter for Residential UV | drinking water | A pre-treatment filter may also be needed to achieve the water quality that is required for the UV system to operate as specified by the manufacturer. | For residential scale UV systems | high |
| #Q082 | monitoring | health | recommended | Peak Event Consideration in Risk Assessments | drinking water | It is important for drinking water providers to consider these peak events in their site-specific assessments, in order to fully understand the potential risks to their drinking water (Health Canada, in preparation). | During site-specific risk assessments | high |