| #Q001 | operational | health | recommended | Infant formula reconstitution | drinking water | In areas where the level of manganese in drinking water is above the guideline, it is recommended that an alternate source of water be used to reconstitute infant formula. | When the level of manganese in drinking water is above the guideline | high |
| #Q002 | monitoring | operational | mandatory | System-specific monitoring programs | drinking water | Considering that manganese levels can vary significantly in source water and within treatment plants and distribution systems, it is necessary to design system-specific monitoring programs that enable utilities to have a good understanding of manganese levels from source to tap. | | high |
| #Q003 | monitoring | operational | recommended | Risk-based monitoring program design | drinking water | Monitoring programs should be designed based on risk factors that contribute to the likelihood that manganese may be elevated within the drinking water system; they may include factors such as historical loading of manganese into the system, lack of treatment, limited distribution system maintenance and variable source and distribution system water chemistry. | | high |
| #Q004 | monitoring | operational | recommended | Source water characterization | drinking water | Water sources should be characterized to determine if manganese is present. | | high |
| #Q005 | monitoring | operational | recommended | Surface water sampling periods | drinking water | This should include sampling during periods when manganese is most likely to be elevated in surface waters, such as during thermal stratification in the summer and lake turnover in the fall. | Surface waters subject to seasonal stratification | high |
| #Q006 | monitoring | operational | recommended | Well field characterization | drinking water | While manganese concentrations in groundwater are less likely to fluctuate between seasons, large variations have been observed between wells located in close proximity to each other. Therefore, all wells in a well field should be characterized. | Groundwater supplies utilizing well fields | high |
| #Q007 | monitoring | operational | recommended | Surface water monitoring frequency | drinking water | Monitoring of surface water should be conducted quarterly, with weekly monitoring being done during summer and fall in lakes and reservoirs subject to stratification and/or large fluctuations in manganese concentrations. | Surface water sources | high |
| #Q008 | monitoring | operational | recommended | Groundwater monitoring frequency | drinking water | Groundwater sources should be monitored semi-annually. | Groundwater sources | high |
| #Q009 | monitoring | operational | recommended | Iron monitoring in source water | drinking water | It is also worth noting that iron and manganese often co-occur in source water and can also cause water discolouration. Therefore, it is recommended that utilities determine if iron is also present in the source water. | | high |
| #Q010 | monitoring | operational | mandatory | Treatment and process monitoring | drinking water | Utilities that treat their water to remove manganese also need to conduct frequent monitoring of raw and treated water, in order to make necessary process adjustments and to ensure that treatment processes are effectively removing manganese concentrations below the MAC and the AO. | Utilities treating water for manganese removal | high |
| #Q011 | monitoring | operational | recommended | Fractionation of samples | drinking water | Appropriate filtration should be conducted on a portion of samples collected to determine the particulate and dissolved manganese components. | Treatment plant monitoring | high |
| #Q012 | monitoring | operational | recommended | Distribution system accumulation monitoring | drinking water | Since manganese can accumulate and release in distribution systems, monitoring within the distribution system at a variety of locations should be conducted for systems where manganese is or was historically present in the source water. | Systems where manganese is or was historically present in the source water | high |
| #Q013 | monitoring | operational | guidance | Event-based monitoring during hydraulic or chemical disturbances | drinking water | Event-based monitoring may be needed during conditions where risk of release is increased, such as following any hydraulic disturbances to the system (e.g., main breaks or hydrant flushing) or changes in water chemistry (e.g., changes to pH, temperature, source water type or uncontrolled source water blending, chlorine residual, or uncontrolled disinfectant blending). | Hydraulic disturbances or changes in water chemistry | high |
| #Q014 | monitoring | operational | recommended | Discoloured water event monitoring | drinking water | Monitoring should also be conducted during any discoloured water event, although the absence of discoloured water should not be interpreted as the absence of a manganese release. | Discoloured water events | high |
| #Q015 | monitoring | operational | recommended | Monitoring co-occurring metals | drinking water | Monitoring for manganese should be done in conjunction with other metals that can co-occur in the distribution system and have been shown to release with manganese (e.g., iron, arsenic, lead). | | high |
| #Q016 | monitoring | health | recommended | Compliance monitoring locations | drinking water | For systems where manganese is present in the source water, including systems that are not treating their water for manganese removal, the MAC applies to water entering and within the distribution system. Therefore, compliance monitoring for manganese should be conducted at the point of entry to the distribution system, as well as throughout the distribution system. | Systems where manganese is present in the source water | high |
| #Q017 | monitoring | operational | recommended | Compliance sample collection distribution | drinking water | Some samples should be collected from sites within the distribution system that are in close proximity to the treatment plant and from hydrants and valves, as well as from drinking water taps from public or private buildings. | | high |
| #Q018 | monitoring | operational | recommended | Routine compliance monitoring frequency | drinking water | At a minimum, routine monitoring is recommended to be conducted quarterly. | | high |
| #Q019 | monitoring | operational | recommended | Event-based compliance monitoring | drinking water | In addition, event-based monitoring should be conducted during conditions where the risk of release is increased or when discolouration of water has been reported. | Increased risk of release or reported water discolouration | high |
| #Q020 | monitoring | health | recommended | Annual private well testing | drinking water | Homeowners with private wells are also encouraged to have their water tested for manganese once a year to ensure that the concentration in their water supply is below the MAC. | Private wells | high |
| #Q021 | monitoring | health | recommended | Private well treatment device testing | drinking water | Homeowners with private wells using point-of-entry (POE) or point-of-use (POU) treatment devices should conduct routine testing on both the water entering the treatment device and the treated water to verify that the treatment device is effective. | Private wells using POE or POU treatment devices | high |
| #Q022 | corrective_action | health | recommended | MAC exceedance investigation and correction | drinking water | An exceedance of the MAC should be investigated and followed by the appropriate corrective actions. | Exceedance of the maximum acceptable concentration | high |
| #Q023 | monitoring | operational | recommended | Sample filtration for dissolved metals | drinking water | For dissolved metals, samples should be filtered at the time of collection using preconditioned plastic filtering devices under either vacuum or pressure. | Measuring dissolved metal concentrations | high |
| #Q024 | monitoring | operational | recommended | Filtrate acidification | drinking water | The filtrate should be acidified to pH <2 with concentrated nitric acid. | Following sample filtration for dissolved metals | high |
| #Q025 | monitoring | operational | recommended | Particulate manganese filter retention | drinking water | For particulate manganese, the filter should be retained and the particulate material on it digested in the laboratory using appropriate methods | Measuring particulate manganese concentrations | high |
| #Q026 | monitoring | operational | mandatory | Colloidal manganese quantification | drinking water | If colloidal manganese is present it will pass through 0.20 µm filters and it will be incorrectly quantified as dissolved manganese. Therefore, following initial filtering through a 0.20 µm filter, the sample will require additional filtering through a 30,000 dalton molecular weight cut-off filter when quantification of colloidal manganese is needed. | When quantification of colloidal manganese is needed | high |
| #Q027 | monitoring | operational | recommended | Treatment unit process monitoring | drinking water | Utilities should conduct monitoring within treatment plants, including periodically determining the different forms of manganese (e.g., dissolved and particulate) to ensure that unit processes are adequately removing manganese. | | high |
| #Q028 | treatment | operational | recommended | Jar testing for oxidant selection | drinking water | Utilities should conduct jar testing to assess which oxidants may be effective with their source water and treatment plant design prior to selecting an oxidant. | Prior to selecting a chemical oxidant for manganese removal | high |
| #Q029 | treatment | operational | recommended | Oxidant addition point | drinking water | It is generally recommended that these oxidants be added prior to coagulation/ flocculation processes so that the colloidal particles can be destabilized and removed through conventional sedimentation and filtration processes | When using permanganate, ClO2 and ozone to oxidize Mn(II) | high |
| #Q030 | treatment | operational | recommended | Preparation for biological filtration conversion | drinking water | It is recommended that utilities intending to convert an existing MnOx(s)-coated media filter consider removing the filter and cleaning or replacing it prior to converting to biological filtration | Transitioning from MnOx(s)-coated media filtration to biological filtration | high |
| #Q031 | monitoring | operational | recommended | Residual-processing side stream sampling | drinking water | Careful sampling of dissolved Mn(II) concentrations in these residual-processing side streams is strongly recommended. | | high |
| #Q032 | treatment | operational | recommended | Residual-processing side stream treatment | drinking water | Likewise, treatment of such side streams for dissolved Mn(II) removal should be considered. | | high |
| #Q033 | operational | operational | recommended | Distribution system manganese control | drinking water | Utilities should ensure that manganese treatment and control measures include consideration of the deposition and possible release of manganese in the distribution system. | | high |
| #Q034 | monitoring | operational | recommended | Distribution system sampling diversity | drinking water | Given that manganese levels can change throughout the distribution system, it is recommended that a sampling program include sites at various locations throughout the system to help characterize typical levels of manganese as well as post-treatment manganese levels. | | high |
| #Q035 | operational | operational | mandatory | Clear water front approach requirement | drinking water | the 'clear water front' approach, which requires that the upstream water used to flush pipes come from pipes with no resuspendable material, so as to avoid introducing sediment into the flushed pipe. | During unidirectional flushing | high |
| #Q036 | operational | operational | mandatory | Targeted water main cleaning strategy | drinking water | the cleaning strategy must be targeted and tailored to the pipe material and sediment characteristics, and best practices must also be applied to minimize exposure to the disturbed sediment. | Managing manganese deposits in distribution systems | high |
| #Q037 | monitoring | operational | recommended | Pre-installation water testing | drinking water | Before a treatment device is installed, the water should be tested by an accredited laboratory to determine the general water chemistry and verify the presence and concentrations of manganese in the source water. | Residential scale treatment | high |
| #Q038 | monitoring | health | recommended | Periodic residential device 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. | Residential scale treatment | high |
| #Q039 | operational | operational | recommended | Residential treatment 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 service it when required. | Residential scale treatment | high |
| #Q040 | operational | health | recommended | NSF/ANSI certification for residential components | drinking water | Health Canada strongly recommends that any chemicals and components used in these treatment systems be certified to NSF/ANSI Standard 60: Drinking Water Treatment Chemicals-Health Effects (NSF/ANSI, 2015a), NSF/ANSI Standard 61: Drinking Water System Components-Health Effects (NSF/ANSI, 2016a) and NSF/ANSI Standard 372: Drinking Water System Components-Lead Content (NSF/ANSI, 2016b). | Residential scale treatment | high |
| #Q041 | monitoring | operational | recommended | Routine monitoring of greensand filtration | drinking water | it is important to routinely monitor the manganese concentration in the water treated by greensand filtration to ensure that the system is effectively removing manganese and that the filters are not releasing it. | Residential scale greensand filtration | high |
| #Q042 | operational | health | recommended | Water softener bypassing | drinking water | it is recommended that a portion of the water (i.e., kitchen tap) bypass the softener altogether to limit these inputs. | Homeowners using residential softening units | high |
| #Q043 | design | operational | recommended | Treated water goal establishment | drinking water | It is recommended that utilities establish a treated water goal of 0.015 mg/L or less for the design and operation of manganese treatment plants. | Design and operation of manganese treatment plants | high |
| #Q044 | administrative | operational | recommended | Distribution system management plan development | drinking water | It is recommended that utilities develop a distribution system management plan to minimize the likelihood of manganese release events in the distribution system. | | high |
| #Q045 | monitoring | operational | guidance | Reduced monitoring consideration | drinking water | Authorities may consider reduced monitoring when it has been demonstrated that manganese is present at concentrations equal to or below 0.02 mg/L in the source water and/or appropriate treatment is in place. | Manganese present <= 0.02 mg/L and/or appropriate treatment in place | high |
| #Q046 | monitoring | operational | guidance | Colloidal manganese quantification consideration | drinking water | Utilities that are experiencing difficulties controlling manganese in treated water, and that are directly oxidizing manganese using potassium permanganate, chlorine dioxide or ozone, may also consider quantifying the colloidal manganese fraction of selected samples within the treatment train. | Difficulties controlling manganese and using direct oxidation (permanganate, chlorine dioxide, or ozone) | high |
| #Q047 | operational | operational | mandatory | Permanganate dosing optimization | drinking water | In practice, dosing of permanganate to oxidize Mn(II) must be precisely optimized to completely oxidize Mn(II) without resulting in any excess permanganate in the treated water. | When using permanganate to oxidize Mn(II) | high |
| #Q048 | administrative | reporting | recommended | Implementation guidance source | 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 |
| #Q049 | corrective_action | health | guidance | Corrective action investigation steps | drinking water | Depending on the location and extent of the exceedance(s), investigation to determine its cause may include the following: - continue monitoring manganese at appropriate locations until levels are below the MAC. - confirm source water concentrations; - verify treatment plant operations and treated water concentrations; - review distribution system operation and maintenance activities to determine if hydraulic release occurred; - verify distribution system water quality (e.g., pH, oxidation/reduction potential (ORP), chlorine residual, turbidity) to determine if chemical release occurred. | Upon MAC exceedance | high |
| #Q050 | corrective_action | health | guidance | Corrective action notification and advisories | drinking water | Based on the results of the investigation and the significance and extent of the manganese exceedance, corrective actions may include the following: - notify communities and other appropriate authorities; - issue a 'do not consume' advisory; - consider treatment plant adjustments; - conduct targeted and tailored distribution system maintenance activities according to best practices, which may include unidirectional flushing, ice pigging and swabbing. | Following MAC exceedance investigation | high |
| #Q051 | operational | health | recommended | Chlorine dioxide feed dose limit | drinking water | to ensure that the chlorite and chlorate guidelines can be met, it is recommended that treatment plants using ClO2 as a primary disinfectant not exceed a feed dose of 1.2 mg/L | When using ClO2 as primary disinfectant | high |
| #Q052 | operational | operational | mandatory | Oxidation completion for membrane systems | drinking water | In these cases it is important that the oxidation reactions be completed before the water reaches the membranes, as formation of precipitates within the membrane pores can damage the membrane structure. | Potassium permanganate/ultrafiltration plants | high |
| #Q053 | operational | operational | mandatory | Adsorptive media oxidant requirement | drinking water | Continuous or intermittent dosing of an oxidant into the raw water prior to contact with the medium is required to maintain the MnOx(s) adsorption sites | When using MnOx(s)-coated filter media | high |
| #Q054 | operational | operational | mandatory | Intermittent regeneration offline requirement | drinking water | The greensand then needs to be taken offline so that an oxidant can be applied to oxidize the adsorbed Mn(II) and create new adsorption sites. | During intermittent regeneration of greensand filters | high |
| #Q055 | operational | operational | guidance | Reverse osmosis membrane pretreatment | drinking water | A consumer may need to pretreat the influent water to reduce fouling and extend the service life of the membrane. | Residential RO systems | high |
| #Q056 | reporting | reporting | mandatory | Total manganese comparison procedure | drinking water | Total manganese includes both the dissolved and particulate forms of manganese in a water sample. Therefore, if the two forms are measured separately, the two concentrations must be added before comparison with the MAC and AO. | When dissolved and particulate forms are measured separately | high |
| #Q057 | monitoring | operational | guidance | Troubleshooting monitoring at key treatment steps | drinking water | Monitoring within the treatment plant, at key treatment steps, may be needed if a utility is having difficulty controlling manganese concentrations in the treated water. | When a utility is having difficulty controlling manganese concentrations | high |
| #Q058 | monitoring | operational | guidance | Process monitoring methods | drinking water | In many cases, process monitoring within a treatment plant can be conducted using colorimetric methods to reduce analytical costs. | Within treatment plant process monitoring | high |
| #Q059 | monitoring | operational | guidance | Reduced distribution monitoring eligibility | drinking water | Utilities that undertake preventive measures with stable hydraulic, physical and water quality conditions and have baseline data indicating that manganese does not occur in the system may conduct less frequent monitoring. | Systems with stable conditions and baseline data indicating no manganese | high |
| #Q060 | monitoring | operational | recommended | Microwave-assisted digestion recommendation | drinking water | Microwave-assisted digestion (SM 3030 K) is recommended for analysis of total recoverable manganese using SM methods that are based on ICP-MS. | When using SM methods based on ICP-MS | high |
| #Q061 | prohibition | health | mandatory | Compliance monitoring analytical restriction | drinking water | Therefore, these methods are best suited to monitoring within treatment plants to assess treatment effectiveness and not for compliance monitoring. | When using colorimetric methods | high |
| #Q062 | monitoring | operational | mandatory | Intermittent regeneration performance monitoring | drinking water | This method requires careful monitoring of Mn(II) in the treated water to ensure that the greensand medium is taken offline and regenerated prior to a significant amount of dissolved Mn(II) passing through the filter and into the finished water. | Intermittent regeneration method | high |
| #Q063 | treatment | operational | recommended | Chlorine shift impact assessment | drinking water | Utilities that are considering moving the application point of chlorine to a point following filtration should assess the potential for filter media to release manganese. | When moving chlorine application point downstream of filters | high |
| #Q064 | monitoring | health | mandatory | Sequestration strategy monitoring | drinking water | When sequestration is used as a management strategy, routine sampling in the treated water and within the distribution system to measure the total manganese concentration is needed to ensure that the concentration remains below the MAC. | When sequestration is used as a management strategy | high |
| #Q065 | operational | health | recommended | Residential device certification recommendation | drinking water | Health Canada... strongly recommends that consumers use devices that have been certified by an accredited certification body as meeting the appropriate NSF International (NSF)/American National Standards Institute (ANSI) drinking water treatment unit standards. | Residential scale treatment | high |
| #Q066 | treatment | operational | guidance | Combined treatment for elevated concentrations | drinking water | Well owners with high manganese concentrations (>2 mg/L) may need to combine two treatment technologies (such as POE ion exchange followed by POU RO0 in order to achieve treated water concentrations below 100 µg/L. | Manganese concentrations > 2 mg/L in private wells | high |
| #Q067 | operational | operational | recommended | Bench- and pilot-scale testing | drinking water | As utilities seek to manage manganese and other treatment goals through changes in source water, treatment processes, water quality amendments and distribution system management practices, testing at the bench- and pilot-scale levels as well as in the field (particularly for water main maintenance strategy development) should be used to help identify some of the unintended consequences of these system changes. | When seeking to manage manganese through changes in source water or treatment processes | high |
| #Q068 | operational | operational | mandatory | Pigging procedural caution | drinking water | Caution must be practised when employing pigging, as it is not appropriate for all pipe and water quality types. | When employing pigging to remove sediments | high |
| #Q069 | monitoring | operational | recommended | Analytical filter specification | drinking water | Membrane filters with pore diameter sizes of between 0.22 µm and 0.45 µm are recommended for fractionating dissolved and particulate manganese | For fractionating dissolved and particulate manganese during monitoring | high |
| #Q070 | operational | operational | mandatory | Biofiltration operational conditions | drinking water | The operating conditions required to establish an adequate MOB population in filters include maintaining aerobic conditions with a minimum DO level of 5 mg/L, a redox potential of 300-400 mV, and pHs of >= 6.3 | To establish an adequate manganese-oxidizing bacteria (MOB) population in filters | high |
| #Q071 | operational | operational | recommended | MnOx-coated media operational conditions | drinking water | The key operational conditions for this process to function properly... include a free chlorine concentration in the filtered water of 0.5-1.0 mg/L (to ensure effective MnOx(s) coating regeneration) and a filter-applied pH of 6.0 or higher, as lower pH levels result in competition for Mn(II) adsorption sites from H + ions. | For MnOx(s)-coated media filtration to function properly | high |
| #Q072 | operational | operational | recommended | Water main flushing best practices | drinking water | Conventional water main flushing... is a strategy that should be applied to decrease water age and be conducted using best practices, including flushing at a velocity velocity low enough as not to disturb sediment | During conventional water main flushing | high |
| #Q073 | operational | operational | mandatory | Pyrolusite backwashing requirement | drinking water | pyrolusite media have a very high specific gravity (>4.0) and so require substantially higher hydraulic loading rates during backwashing operations in order to fluidize the media bed. | During backwashing operations for pyrolusite filters | high |
| #Q074 | operational | operational | recommended | Distribution water quality stability control | drinking water | Friedman et al. (2010) identified several key water quality conditions that should be controlled in order to maintain water stability for deposited inorganics, including pH, ORP, and corrosion control measures, as well as avoiding both the uncontrolled blending of surface water and groundwater and the uncontrolled blending of chlorinated and chloraminated water. | To maintain water stability for deposited inorganics in the distribution system | high |
| #Q075 | monitoring | operational | recommended | Analytical verification of metal recovery | drinking water | Similarly, APHA et al. (2012) recommends verifying whether adequate recovery of metals has occurred in different sample matrices by comparing digested and undigested results. | During laboratory analysis of metals in drinking water samples | high |
| #Q076 | monitoring | operational | guidance | Baseline water quality boundary determination | drinking water | Utilities can determine baseline water quality to establish boundary conditions outside of which an excursion could be expected to trigger a release event (Friedman et al., 2016). | When developing distribution system monitoring and release event triggers | high |
| #Q077 | monitoring | operational | recommended | Risk-based distribution sampling site selection | drinking water | Distribution system sampling locations would ideally be located where there are both increased risk factors for manganese accumulation (e.g., proximity to water treatment plant, pipe materials, biofilm) and event-based release risk factors. | Selection of distribution system monitoring locations | high |
| #Q078 | monitoring | operational | guidance | Distribution sampling sentinel limitation | drinking water | Distribution system sampling should not be viewed as an effective sentinel against release events. | Design and interpretation of distribution system monitoring programs | high |
| #Q079 | operational | operational | mandatory | Sequestration dosage determination | drinking water | The proper dosage of sequestering chemicals must be determined based on the water quality characteristics and the manufacturer's recommendations. | When using chemical sequestration | high |
| #Q080 | operational | aesthetic | recommended | Sequestration usage restriction | drinking water | only for water supplies with manganese levels below the MAC in the source or treated water should it [sequestration] be considered as a control option for reducing the potential for discoloured water | | high |
| #Q081 | operational | operational | mandatory | Reservoir aeration control | drinking water | Careful control is needed to avoid reservoir destratification, which can lead to other water quality issues (Kohl and Medlar, 2006). | When using hypolimnetic aeration or oxygenation | high |
| #Q082 | operational | operational | mandatory | Greensand filter backwashing | drinking water | Backwashing to remove the MnOx particulates is conducted once head loss has reached a specified level (Knocke et al., 1990b). | Manganese greensand continuous regeneration process | high |
| #Q083 | administrative | health | recommended | Residential softening sodium awareness | drinking water | homeowners using residential softening units should be aware that softening systems will increase the concentrations of sodium or potassium in the treated water | | high |