| Req ID | Category | Intent | Legal Status | Name | Subdomain(s) | Context | Conditions | Confidence |
|---|---|---|---|---|---|---|---|---|
| #Q001 | treatment | treatment | recommended | Optimization of existing treatment facilities | drinking water | Existing treatment facilities and processes should be optimized to reduce the formation of disinfection by-products, including NDMA, without compromising the effectiveness of disinfection. | high | |
| #Q002 | operational | treatment | recommended | Selection of coagulants and ion exchange resins | drinking water | To minimize NDMA formation, drinking water utilities should pay special attention when selecting polyelectrolyte coagulants and ion exchange resins and should minimize the use of quaternary amine-based coagulation polymers (Wilczak et al., 2003). | When selecting polyelectrolyte coagulants and ion exchange resins. | high |
| #Q003 | design | treatment | recommended | Assessment of disinfection strategy | drinking water | In particular, the treatment study (including pilot testing) should assess the disinfection strategy for its potential to form disinfection by-products. | When conducting a treatment study to reduce NDMA levels. | high |
| #Q004 | design | treatment | mandatory | Pilot study for UV and AOP treatment | drinking water | Although UV and AOP can reduce concentration of NDMA in water, the selection of that treatment option will require pilot study/consideration regarding the potential formation of NDMA subsequent to chlorination steps. | If selecting UV or AOP treatment options. | high |
| #Q005 | administrative | health | recommended | Certification of residential treatment devices | drinking water | Where consumers choose to use a device, it is important to note that 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/American National Standards Institute (ANSI) standards. | Where consumers choose to use a drinking water treatment device. | high |
| #Q006 | design | treatment | recommended | Testing of RO filters | drinking water | Because NDMA reduction is dependent on membrane type, testing of various RO filters should be done to select the most appropriate system for the water being treated. | When selecting RO systems for NDMA reduction. | high |
| #Q007 | treatment | treatment | recommended | Maintenance of RO technology products | drinking water | Products that use RO technology can lose removal capacity through usage and time and should be maintained or replaced as per the manufacturer's recommendations. | Applies to consumer products using RO technology. | high |
| Req ID | Category | Intent | Legal Status | Name | Subdomain(s) | Limit Type | Limit Value | Context | Conditions | Confidence |
|---|---|---|---|---|---|---|---|---|---|---|
| #P001 | chemical | health | mandatory | NDMA province standard | drinking water | requirement | 0.009 µg/L | Ontario's standard for NDMA in finished drinking water | Finished drinking water | high |
| #P002 | physical | unknown | mandatory | Skin permeability coefficient (Kp) | drinking water | requirement | > 0.024 cm/h | In order for a chemical to contribute at least 0.15 litre-equivalents (L-eq) during showering and bathing | Determining whether dermal exposure represents a significant route of exposure | medium |
| #P003 | physical | unknown | recommended | Air to water NDMA concentration (Fair:water) | drinking water | requirement | > 0.00089 unitless | For a tier 1 goal of 0.15 L-eq to evaluate the inhalation route of exposure during bathing or showering | medium | |
| #P004 | chemical | reporting | guidance | EPA Method 521 minimum reporting level | drinking water | unknown | 1.6 ng/L | Lowest concentration minimum reporting level for EPA Method 521 | high | |
| #P005 | chemical | reporting | guidance | EPA Method 521 detection limit | drinking water | unknown | 0.28 ng/L | Detection limit for EPA Method 521 analysis of NDMA | high | |
| #P006 | design | treatment | guidance | UV dose for 90% reduction of NDMA | drinking water | treatment_goal | 1000 mJ/cm² | The UV dose required for 90% reduction of NDMA is about 1000 mJ/cm² | Municipal scale treatment using UV irradiation | high |
| #P007 | operational | health | mandatory | Standard daily drinking water consumption | drinking water | requirement | 1.5 L/d | Value normally considered for ingestion of drinking water in exposure assessments | Tier 1 multi-route exposure assessment | high |
| #P008 | operational | health | mandatory | Dermal absorption litre-equivalent (L-eq) for NDMA | drinking water | requirement | 0.4 L-eq/d | Value calculated to account for dermal absorption of NDMA in drinking water | high | |
| #P009 | operational | health | mandatory | Total multi-route drinking water consumption | drinking water | requirement | 1.9 L/d | Value for total exposure from drinking water (ingestion + dermal) used in MAC calculation | When dermal absorption is considered significant (> 0.024 cm/h) | high |
| #P010 | design | health | mandatory | Bathroom air volume for assessment | drinking water | requirement | 6420 L | Volume of air in an average bathroom used in the multi-route exposure assessment model | Used to calculate the air to water ratio (80.25) | high |
| #P011 | design | health | mandatory | Average shower/bath water volume | drinking water | requirement | 80 L | Average volume of water used during the showering/bathing event in the multi-route model | Used to calculate the air to water ratio (80.25) | high |
| #P012 | operational | health | mandatory | Transfer efficiency (McKone and Knezovich) | drinking water | requirement | 61 % | Percentage used in the inhalation exposure assessment formula | Multi-route assessment of volatile organic chemicals | high |
| #P013 | operational | treatment | recommended | Recommended Cl:N molar ratio for NDMA reduction | drinking water | treatment_goal | 4 molar ratio | Chlorination at this ratio produced negligible levels of NDMA compared to lower ratios | Secondary disinfection/breakpoint chlorination | high |
| #P014 | operational | health | mandatory | Significant route contribution threshold | drinking water | requirement | 10 % | Threshold used to determine if dermal or inhalation routes must be included in multi-route exposure assessment | Contribution relative to 1.5 L/d drinking water consumption | high |
| #P015 | operational | treatment | recommended | Free chlorine contact time for NDMA reduction | drinking water | treatment_goal | 2 h | Contact time prior to chloramination to achieve 93% reduction in NDMA formation | Bench-scale optimization for treatment plants | high |
| #P016 | design | treatment | guideline | UV dose for virus inactivation | drinking water | treatment_goal | 100 mJ/cm² | Reference value for disinfection efficacy compared to NDMA reduction requirement of 1000 mJ/cm² | Standard municipal UV disinfection systems | high |
| Req ID | Category | Name | Context | Confidence |
|---|---|---|---|---|
| #D001 | NDMA | N -Nitrosodimethylamine | high | |
| #D002 | DMA | dimethylamine | high | |
| #D003 | 2,4-D | 2,4-dichlorophenoxyacetic acid | high | |
| #D004 | MCPA | 4-(2-methyl-4-chlorophenoxy)acetic acid | high | |
| #D005 | Kp | skin permeability coefficient | high | |
| #D006 | Fair:water | air to water NDMA concentration | high | |
| #D007 | Kaw | Henry's law constant | medium | |
| #D008 | EPA | U.S. Environmental Protection Agency | high | |
| #D009 | AOP | advanced oxidation process | high | |
| #D010 | RO | reverse osmosis | high | |
| #D011 | ANSI | American National Standards Institute | high | |
| #D012 | SCC | Standards Council of Canada | high | |
| #D013 | NSF | NSF International | medium | |
| #D014 | DMN | N -Nitrosodimethylamine | high | |
| #D015 | DMNA | N -Nitrosodimethylamine | high | |
| #D016 | Kow | n -octanol/water partition coefficient | high | |
| #D017 | Kaw | Henry's law constant | high | |
| #D018 | MW | molecular weight | high | |
| #D019 | Leq | litre-equivalents | high | |
| #D020 | UV | ultraviolet radiation | high | |
| #D021 | dimethylnitrosoamine | N -Nitrosodimethylamine | high | |
| #D022 | N, N-dimethylnitrosoamine | N -Nitrosodimethylamine | high | |
| #D023 | N-methyl-N-nitrosomethanamine | N -Nitrosodimethylamine | high | |
| #D024 | N-nitroso-N, N-dimethylamine | N -Nitrosodimethylamine | high | |
| #D025 | ambient air | outdoor air | high |