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Document ID ca-on-dwtc-2021-06-24-2 Title Drinking water threats and circumstances URL https://www.ontario.ca/page/procedure-disinfection-drinking-water-ontario Jurisdiction /ca/on Subdomain(s) none Language Status completed Analyzed at 2026-05-12 04:21:38.245841+00:00 Relevance inventory_targeted_fetch

Q Qualitative Requirements (43)

Req ID Category Intent Legal Status Name Subdomain(s) Context Conditions Confidence
#Q001treatmenthealthmandatoryMinimum disinfection treatment for ground waterdrinking waterall municipal drinking-water systems and regulated non-municipal drinking-water systems that are required to provide a minimum level of treatment must have a treatment process that consists of disinfection as a minimum, if the system obtains water from a raw water supply which is ground water;System obtains water from a raw water supply which is ground waterhigh
#Q002treatmenthealthmandatoryMinimum treatment for surface water and GUDIdrinking waterall regulated drinking-water systems that obtain water from a raw water supply which is surface water or ground water under the direct influence of surface water, must provide a minimum level of treatment consisting of chemically assisted filtration and disinfection or other treatment capable of producing water of equal or better quality;System obtains water from surface water or ground water under the direct influence of surface waterhigh
#Q003treatmenthealthmandatoryDisinfectant residual in distribution systemdrinking waterall drinking water entering a distribution system that has been treated and is otherwise ready for consumption must contain a disinfectant residual that persists throughout the distribution system unless a point of entry treatment approach is used as permitted by the Regulation;Unless a point of entry treatment approach is used as permitted by the Regulationhigh
#Q004monitoringtreatmentmandatoryMonitoring of treatment effectivenessdrinking watereffectiveness of the provided treatment must be adequately monitored.high
#Q005designoperationalrecommendedDesign conformance with Ten State Standardsdrinking waterThe design and construction of both primary and secondary disinfection facilities should normally conform to the criteria set out in the Recommended Standards for Water Works ("Ten State Standards") published by the Great Lakes - Upper Mississippi River Board of State and Provincial Public Health and Environmental Managershigh
#Q006administrativeoperationalmandatoryDemonstration of design appropriatenessdrinking watera proponent may be required to demonstrate that any submitted design addresses the issues otherwise addressed by a 'Ten State' recommendation.medium
#Q007designtreatmentrecommendedConsideration of raw water supply characteristicsdrinking waterDesign of the treatment processes should consider the characterization, variability and vulnerability of the raw water supply.high
#Q008monitoringtreatmentrecommendedIndividual assessment of water suppliesdrinking waterAll water supplies should be individually assessed by measuring relevant water quality parameters and utilizing, where chemical disinfection is used, the CT tables provided to determine the appropriate disinfectant dosage.high
#Q009treatmenthealthmandatoryGround water treatment overall performancedrinking waterWhere the drinking-water system obtains water from a raw water supply which is ground water, the treatment process must, as a minimum, consist of disinfection and must be credited with achieving an overall performance that provides, at a minimum 2-log (99%) removal or inactivation of viruses before the water is delivered to the first consumer.System obtains water from a raw water supply which is ground waterhigh
#Q010treatmenthealthmandatorySurface water and GUDI treatment capabilitydrinking waterDrinking-water systems that obtain water from a raw water supply which is surface water or ground water under the direct influence of surface water must have a treatment process that is capable of producing water of equal or better quality than a combination of well-operated chemically assisted filtration and disinfection processes would provide.System obtains water from surface water or ground water under the direct influence of surface waterhigh
#Q011treatmenthealthmandatoryMinimum disinfection contribution to overall treatmentdrinking waterAt least 0.5-log removal or inactivation of Giardia cysts and 2-log removal or inactivation of viruses must be provided through the disinfection portion of the overall water treatment process.System obtains water from surface water or GUDIhigh
#Q012treatmenthealthmandatoryTreatment via disinfection alone for GUDIdrinking waterShould the approving Director concur that it is acceptable that the required treatment is achieved through disinfection alone, the disinfection process or combination of disinfection processes used in these circumstances must be capable of providing an effective inactivation of oocysts, cysts, and viruses.If the approving Director concurs that disinfection alone is acceptable for GUDIhigh
#Q013treatmenthealthmandatoryCompletion of primary disinfectiondrinking waterThe entire process of primary disinfection must be completed within the water treatment component of the system, which may include a dedicated part of the piping upstream of the first consumer connection.high
#Q014treatmenthealthmandatoryPrimary disinfection in point of entry treatment unitsdrinking waterWhere point of entry treatment units are permitted by the Regulation, primary disinfection must be completed within the point of entry treatment unit.When point of entry treatment units are usedhigh
#Q015designtreatmentmandatoryBalancing pathogen inactivation and disinfection by-productsdrinking waterProcess selection decisions must consider and balance the need to inactivate human pathogens while minimizing the production of disinfection by-products.high
#Q016administrativereportingmandatoryRationale for chemical disinfectants other than free chlorinedrinking waterWhere primary chemical disinfectants other than free chlorine are selected, the suitability and effectiveness of these processes must be established on a site-specific basis and the rationale for the selection should be documented by the designer of the drinking-water system or the professional engineer who is responsible for preparing a report on the system.When primary chemical disinfectants other than free chlorine are selectedhigh
#Q017designtreatmentrecommendedDetermination of actual T10 valuesdrinking waterActual T10 values can be significantly different from calculated hydraulic detention times (T) and should be determined by a tracer study, mathematical modeling or by calculations using typical baffle conditions.high
#Q018monitoringtreatmentrecommendedCT value continuous measurement basisdrinking waterCalculations should be based on the disinfectant residual concentration as continuously measured at the end of, or at intermediate points within, each process step.high
#Q019operationaltreatmentrecommendedMaintenance of calculated CT valuedrinking waterThe calculated CT value should, at all times during plant operation, be equal to or greater than the required overall CT value.high
#Q020monitoringtreatmentmandatoryValidation of non-254 nm continuous UV light sourcesdrinking waterWhere the considered technology uses UV light source providing radiation at wavelengths different from continuous monochromatic 254 nm wavelength light that is close to the maximally effective germicidal wavelengths of 260-265 nm, the dose delivered by the considered technology must be validated also by empirical biodosimetry testing and the dose must be expressed as a 254 nm-equivalent UV dose.When technology uses wavelengths different from continuous monochromatic 254 nm wavelength lighthigh
#Q021designtreatmentrecommendedDesign considerations for UV facilitiesdrinking waterUV facilities should be designed taking into account appropriate reliability and redundancy measures, and the light transmission and scale formation/fouling potential in the UV reactor specific to the quality of the raw water supply.high
#Q022treatmenthealthmandatorySecondary disinfection following UV primary disinfectiondrinking waterWhere the regulation requires the provision of secondary disinfection for a drinking-water system, primary disinfection must be followed by another process, normally chlorination, which introduces and maintains a persistent disinfectant residual throughout the distribution system.Where secondary disinfection is required and UV is usedhigh
#Q023administrativetreatmentmandatoryDemonstration for alternative disinfectantsdrinking waterIn the case of other disinfectants or a combination of disinfectants other than those discussed in this procedure it must be demonstrated and documented that the disinfection process in conjunction with filtration (where required) achieves the required level of pathogen removal or inactivation.Use of disinfectants other than those discussed in the procedurehigh
#Q024operationaltreatmentmandatoryConventional filtration operational criteriadrinking waterIn order to be considered conventional filtration and meet or exceed the 2.5 log Giardia cyst removal, the 2.0 log Cryptosporidium oocyst removal and 2.0 log virus removal credits, the filtration process must meet the following criteria: use a chemical coagulant at all times when the treatment plant is in operation; monitor and adjust chemical dosages in response to variations in raw water quality; maintain effective backwash procedures, including filter-to-waste or an equivalent procedure during filter ripening to ensure that the effluent turbidity requirements are met at all times; continuously monitor filtrate turbidity from each filter; and, meet the performance criterion for filtered water turbidity of less than or equal to 0.3 NTU in 95% of the measurements each month.To claim conventional filtration creditshigh
#Q025operationaltreatmentmandatorySlow sand filtration operational criteriadrinking waterIn order to meet or exceed the 2.0 log Giardia cyst removal, the 2.0 log Cryptosporidium oocyst removal and 2.0 log virus removal credits, the slow sand filtration process must meet the following criteria: maintain an active biological layer; regularly carry out effective filter cleaning procedures; use filter-to-waste or an equivalent procedure during filter ripening periods; continuously monitor filtrate turbidity from each filter or take a daily grab sample; and, meet the performance criterion for filtered water turbidity of less than or equal to 1.0 NTU in 95% of the measurements each month.To claim slow sand filtration creditshigh
#Q026operationaltreatmentmandatoryDiatomaceous earth filtration operational criteriadrinking waterIn order to meet or exceed the 2.0 log Giardia cyst removal, the 2.0 log Cryptosporidium oocyst removal and 1.0 log virus removal credit, the DE filtration process must meet the following criteria: maintain a minimum thickness of pre-coat; maintain effective filter cleaning procedures; maintain full recycle or partial discharge to waste of water flow during filter precoat until the recycle stream turbidity falls to below 1.0 NTU; continuously monitor filtrate turbidity from each filter; and, meet the performance criterion for filtered water turbidity of less than or equal to 1.0 NTU in 95% of the measurements each month.To claim DE filtration creditshigh
#Q027operationaltreatmentmandatoryCartridge/Bag filtration operational criteriadrinking waterIn order to claim the 2.0 log Cryptosporidium oocyst removal credit, the cartridge/bag filtration process must meet the following criteria: use filter elements and housing certified for surrogate particle removal evaluation in accordance with testing procedures and manufacturing quality control specified in ANSI/NSF Standard 53 or equivalent; continuously monitor filtrate turbidity from each filter or take a daily grab sample; and ensure that differential pressures across the filter medium do not exceed manufacturer’s rating and materials coming in contact with water conform to ANSI/NSF Standard 61.To claim cartridge/bag filter creditshigh
#Q028operationaltreatmentmandatoryMembrane filtration operational criteriadrinking waterIn order to claim 2.0+ log Cryptosporidium oocyst removal credit, the membrane filtration process must meet the following criteria: maintain effective backwash procedures, including filter-to-waste or an equivalent procedure, to ensure that the effluent turbidity requirements are met at all times; monitor integrity of the membrane by continuous particle counting or equivalently effective means (e.g., intermittent pressure decay measurements); continuously monitor filtrate turbidity; and, meet the performance criterion for filtered water turbidity of less than or equal to 0.1 NTU in 99% of the measurements each month.To claim membrane filtration creditshigh
#Q029administrativetreatmentmandatoryDemonstration for other filtration technologiesdrinking waterIn the case of the provision of a filtration technology other than those discussed in this procedure, before using the technology, it must be demonstrated and documented that the filtration technology in conjunction with disinfection achieves the required level of pathogen removal or inactivation.Use of filtration technologies not discussed in the procedurehigh
#Q030corrective_actionoperationalrecommendedCorrective action for rapid decay of disinfectant residualdrinking waterRapid decay of a disinfectant residual may occur as a result of a number of other causes such as heavy encrustation or sediment accumulation and biofilm activity and may require investigation and specific corrective action such as engineered flow velocity increases, and swabbing or pigging/lining and/or main replacement.When rapid decay of disinfectant residual occurshigh
#Q031treatmenthealthmandatoryDisinfection after construction or repairsdrinking waterAll parts of drinking-water systems in contact with drinking water which are taken out of service for inspection, repair or other activities that may lead to contamination before they are put back in service, must be disinfected in accordance with the provisions of the AWWA Standard for Disinfecting Water Mains (C651), AWWA Standard for Disinfection of Water Storage Facilities (C652), AWWA Standard for Disinfection of Water Treatment Plants (C653), and AWWA Standard for Disinfection of Wells (C654) or an equivalent procedure that ensures the safety of drinking water that is delivered to consumers.Parts taken out of service for inspection, repair, or other activitieshigh
#Q032monitoringtreatmentmandatoryRoutine monitoring for primary disinfectiondrinking waterAll systems providing primary disinfection must ensure that routine monitoring of the relevant parameters associated with the performance of the disinfection process is being carried out to ensure that water that is directed to consumers is being properly disinfected.Systems providing primary disinfectionhigh
#Q033monitoringtreatmentmandatoryContinuous monitoring and alarms for municipal residential systemsdrinking waterPrimary disinfection facilities for all municipal residential drinking-water systems must be equipped with continuous disinfection process monitoring and recording devices with alarms unless otherwise specified in the Regulation.Municipal residential drinking-water systemshigh
#Q034monitoringreportingmandatoryGrab sample testing for non-municipal systems without continuous monitoringdrinking waterNon-municipal systems that do not have continuous monitoring equipment installed must analyze manual grab samples on a daily basis for the parameters specified in the Regulation.Non-municipal systems without continuous monitoring equipmenthigh
#Q035monitoringtreatmentmandatoryFree chlorine residual analyzer continuous sample locationdrinking waterExcept for situations identified below, the free chlorine residual analyzer(s) installed for the purpose of continuous monitoring of a primary disinfection process utilizing free chlorine residual, must take a continuous sample at the downstream end of the primary disinfection process.high
#Q036monitoringtreatmentmandatoryFree chlorine analyzer location ahead of post-disinfection chemicalsdrinking waterIn all cases, the location must be ahead of the point of addition of any post-disinfection chemicals, including those intended for the purpose of ensuring maintenance of disinfectant residual in the distribution system or preventing corrosion in the distribution system.high
#Q037operationaltreatmentmandatoryFree chlorine analyzer calibration frequencydrinking waterEvery free chlorine residual analyzer installed for the purpose of monitoring a primary disinfection process utilizing free chlorine residual, must be calibrated at a frequency necessary to ensure appropriate operation of the analyzer within a quality control band of plus/minus 0.05 mg ⁄ L at a chlorine concentration up to and including 1.0 mg ⁄ L or plus/minus 5.0% at a chlorine concentration greater than 1.0 mg ⁄ L.high
#Q038monitoringtreatmentmandatoryContinuous monitoring of UV parameters and alarmsdrinking waterAll UV disinfection facilities must continuously monitor such parameters that allow the operator to determine that the target design 254 nm-equivalent UV pass through dose or higher is being delivered, and all systems must provide annunciated failure alarms when this design dose is not being delivered.UV disinfection facilitieshigh
#Q039operationaltreatmentmandatoryUV sensor calibration frequencydrinking waterAll sensors that constitute part of the monitoring system must be calibrated at a frequency that maintains their necessary sensitivity and reliability in ensuring that the design UV dose is being achieved.UV monitoring sensorshigh
#Q040monitoringtreatmentmandatoryDaily grab sample testing for turbidity if no continuous monitordrinking waterSystems not required to have continuous monitoring and which choose not to install such equipment must ensure that a water sample is taken at least once a day on each filter effluent line and is tested for turbidity.Systems not required to have continuous monitoring that do not install ithigh
#Q041operationaltreatmentmandatoryTurbidity analyzer calibration frequencydrinking waterEvery water turbidity analyzer installed for the purpose of monitoring the effectiveness of the filtration process (usually ahead of the primary disinfection process) must be calibrated at a frequency necessary to ensure the appropriate operation of the analyzer.high
#Q042prohibitionhealthrecommendedProhibition of chemical addition upstream of DBP precursor removaldrinking waterChemical disinfectant addition should not take place upstream of the precursor removal process(s), unless the use of prechlorination can be justified by the raw water source quality including active mussel veliger content, measurement of DBP formation potential, and other site specific conditions.Unless justified by specific source quality issueshigh
#Q043designhealthmandatoryPriority of pathogen inactivation over DBP minimizationdrinking waterNotwithstanding the above, the treatment processes must be designed and always operated to achieve the required removal or inactivation of pathogens as a priority with the minimization of disinfection by products formation as a secondary objective.high

P Quantitative Requirements (57)

Req ID Category Intent Legal Status Name Subdomain(s) Limit Type Limit Value Context Conditions Confidence
#P001microbiologicaltreatmentmandatoryGround water minimum virus removaldrinking watertreatment_goal>= 2 logachieving an overall performance that provides, at a minimum 2-log (99%) removal or inactivation of viruses before the water is delivered to the first consumerwhere the drinking-water system obtains water from a raw water supply which is ground waterhigh
#P002microbiologicaltreatmentmandatorySurface water Cryptosporidium removaldrinking watertreatment_goal>= 2 logprovides at a minimum a 2-log (99%) removal or inactivation of Cryptosporidium oocystsobtain water from a raw water supply which is surface water or ground water under the direct influence of surface waterhigh
#P003microbiologicaltreatmentmandatorySurface water Giardia removaldrinking watertreatment_goal>= 3 loga 3-log (99.9%) removal or inactivation of Giardia cystsobtain water from a raw water supply which is surface waterhigh
#P004microbiologicaltreatmentmandatorySurface water virus removaldrinking watertreatment_goal>= 4 logand a 4-log (99.99%) removal or inactivation of viruses before the water is deliveredobtain water from a raw water supply which is surface waterhigh
#P005microbiologicaltreatmentmandatoryDisinfection minimum Giardia inactivationdrinking waterrequirement>= 0.5 logAt least 0.5-log removal or inactivation of Giardia cystsprovided through the disinfection portion of the overall water treatment processhigh
#P006microbiologicaltreatmentmandatoryDisinfection minimum virus inactivationdrinking waterrequirement>= 2 logand 2-log removal or inactivation of viruses must be provided through the disinfection portionsurface water and ground water under direct influence of surface waterhigh
#P007designtreatmentmandatoryUV dose for ground waterdrinking waterrequirement>= 40 mJ / cm2254 nm-equivalent UV pass through dose of at least 40 mJ / cm2 is maintainedFor ground water which is not under the direct influence of surface waterhigh
#P008physicaloperationalmandatoryConventional Filtration treated turbiditydrinking waterrequirement<= 0.3 NTUmeet the performance criterion for filtered water turbidity of less than or equal to 0.3 NTUin 95% of the measurements each month for conventional filtrationhigh
#P009chemicaloperationalmandatorySecondary disinfection minimum free chlorinedrinking waterrequirement>= 0.05 mg / Lthere is at least a free chlorine residual of 0.05 mg / Lat all times and at all locations within the distribution system, where there is a daily flowhigh
#P010chemicaloperationalrecommendedSecondary disinfection max free chlorinedrinking waterrequirement<= 4.0 mg / LThe maximum chlorine residual at any time and at any location within the distribution system should not exceed 4.0 mg / Lwhen measured as free chlorinehigh
#P011chemicalhealthmandatoryAcenaphthene Table 1 Agricultural Soil Standardotherrequirement0.05 µg / gFull Depth Background Site Condition Standards for Agricultural or Other Property Usesoil (other than sediment)high
#P012chemicalhealthmandatoryAcenaphthene Table 1 Ground Water Standardotherrequirement4.1 µg / LFull Depth Background Site Condition Standards for All Types of Property Usesground waterhigh
#P013designoperationalguidanceGeneric Standard Volume Validity Thresholdotherrequirement> 340 m3If the contaminated zone has a volume larger than 340m3, generic standards may be non-conservativesource depletion or groundwater transport pathwayshigh
#P014physicaloperationalguidanceOrganic Carbon Content Generic Standard Thresholdotherrequirement< 0.002 focIf average Organic Carbon content of soil above water table is < 0.002, generic standards may be non-conservativesoil above the water tablehigh
#P015physicaloperationalguidanceSurface Water Hardness Validity Thresholdaquatic liferequirement< 70 mg / LAquatic protection values for metals may be non-conservative if surface water total hardness is less than 70mg/L as CaCO3surface water body affected by property contaminant migration via groundwaterhigh
#P016physicaloperationalguidanceSurface Water pH Validity Thresholdaquatic liferequirement< 6.7 pHAquatic protection values for metals and pentachlorophenol may be non-conservative if surface water has pH less than 6.7surface water body affected by property contaminant migration via groundwaterhigh
#P017designoperationalguidanceGeneric Standard Source Dimension Thresholdotherrequirement> 13 metresIf the contaminated zone has a source length or width greater than 13 metres then all pathways which employ source depletion or groundwater transport may be affected.Contaminated zone volume > 340 m3 or dimension > 13 mhigh
#P018physicaloperationalguidanceCapillary Fringe Proximity Thresholdotherrequirement< 0.8 metresIf the annual average of the capillary fringe of the water table is < 0.8 metres from the outer edge of the gravel crush of the building foundation, then the 10 &times; biodegradation factor assumed in the GW2 pathway may be non-conservative.Measurement from outer edge of building foundation gravel crushhigh
#P019chemicalhealthmandatoryAcenaphthylene Table 1 Soil Standard (Agricultural)otherrequirement0.093 µg / gFull Depth Background Site Condition Standards for Agricultural or Other Property UseSoil (other than sediment)high
#P020chemicalhealthmandatoryAldrin Table 1 Ground Water Standardotherrequirement0.01 µg / LFull Depth Background Site Condition Standards for All Types of Property UsesGround Waterhigh
#P021chemicalhealthmandatoryAldrin Table 1 Sediment Standardaquatic liferequirement0.002 µg / gFull Depth Background Site Condition Standards for All Types of Property UsesSedimenthigh
#P022chemicalhealthmandatoryAcetone Table 1 Soil Standard (Agricultural/Other)agricultural water, otherrequirement0.5 µg / gFull Depth Background Site Condition Standards for Agricultural or Other Property Usesoil (other than sediment)high
#P023chemicalhealthmandatoryAcetone Table 1 Soil Standard (Residential/Parkland/Institutional/Industrial/Commercial/Community)otherrequirement0.5 µg / gFull Depth Background Site Condition Standards for Residential/ Parkland/ Institutional/ Industrial/ Commercial/ Community Property Usesoil (other than sediment)high
#P024chemicalhealthmandatoryAcetone Table 1 Ground Water Standarddrinking water, otherrequirement2700 µg / LFull Depth Background Site Condition Standards for All Types of Property Usesground waterhigh
#P025chemicalhealthmandatoryAnthracene Table 1 Soil Standard (Agricultural/Other)agricultural water, otherrequirement0.05 µg / gFull Depth Background Site Condition Standards for Agricultural or Other Property Usesoil (other than sediment)high
#P026chemicalhealthmandatoryAnthracene Table 1 Soil Standard (Residential/Parkland/Institutional/Industrial/Commercial/Community)otherrequirement0.16 µg / gFull Depth Background Site Condition Standards for Residential/ Parkland/ Institutional/ Industrial/ Commercial/ Community Property Usesoil (other than sediment)high
#P027chemicalhealthmandatoryAnthracene Table 1 Ground Water Standarddrinking water, otherrequirement0.1 µg / LFull Depth Background Site Condition Standards for All Types of Property Usesground waterhigh
#P028chemicalhealthmandatoryAnthracene Table 1 Sediment Standardaquatic liferequirement0.22 µg / gFull Depth Background Site Condition Standards for All Types of Property Usessedimenthigh
#P029chemicalhealthmandatoryArsenic Table 1 Soil Standard (Agricultural/Other)agricultural water, otherrequirement11 µg / gFull Depth Background Site Condition Standards for Agricultural or Other Property Usesoil (other than sediment)high
#P030chemicalhealthmandatoryArsenic Table 1 Soil Standard (Residential/Parkland/Institutional/Industrial/Commercial/Community)otherrequirement18 µg / gFull Depth Background Site Condition Standards for Residential/ Parkland/ Institutional/ Industrial/ Commercial/ Community Property Usesoil (other than sediment)high
#P031chemicalhealthmandatoryArsenic Table 1 Ground Water Standarddrinking water, otherrequirement13 µg / LFull Depth Background Site Condition Standards for All Types of Property Usesground waterhigh
#P032chemicalhealthmandatoryArsenic Table 1 Sediment Standardaquatic liferequirement6 µg / gFull Depth Background Site Condition Standards for All Types of Property Usessedimenthigh
#P033chemicalhealthmandatoryAcenaphthene Table 1 Residential/Parkland/Industrial Soil Standardotherrequirement0.072 µg/gFull Depth Background Site Condition Standards; Residential/Parkland/Institutional/Industrial/Commercial/Community Property UseSoil (other than sediment)high
#P034chemicalhealthmandatoryAcenaphthene Table 2 Agricultural/Residential Soil Standard (Coarse)otherrequirement7.9 µg/gFull Depth Generic Site Condition Standards in a Potable Ground Water Condition; Agricultural or Residential/Parkland/Institutional Property UseCoarse textured soilhigh
#P035chemicalhealthmandatoryAcenaphthene Table 2 Agricultural/Residential Soil Standard (Medium/Fine)otherrequirement29 µg/gFull Depth Generic Site Condition Standards in a Potable Ground Water Condition; Agricultural or Residential/Parkland/Institutional Property UseMedium and fine textured soilshigh
#P036chemicalhealthmandatoryAntimony Table 1 Agricultural/Other Soil Standardotherrequirement1 µg/gFull Depth Background Site Condition Standards; Agricultural or Other Property UseSoil (other than sediment)high
#P037chemicalhealthmandatoryAntimony Table 1 Ground Water Standardotherrequirement1.5 µg/LFull Depth Background Site Condition Standards; All Types of Property UsesGround waterhigh
#P038chemicalhealthmandatoryCarbon Tetrachloride Table 2 Ground Water Standard (Coarse)drinking waterrequirement0.79 µg/LFull Depth Generic Site Condition Standards in a Potable Ground Water ConditionCoarse textured soil conditionshigh
#P039chemicalhealthmandatoryCarbon Tetrachloride Table 2 Ground Water Standard (Medium/Fine)drinking waterrequirement5 µg/LFull Depth Generic Site Condition Standards in a Potable Ground Water ConditionMedium and fine textured soilshigh
#P040chemicalhealthmandatoryChloride Table 1 Ground Water Standardotherrequirement790000 µg/LFull Depth Background Site Condition Standards; All Types of Property UsesGround waterhigh
#P041chemicaloperationalmandatorySecondary disinfection minimum chlorine dioxidedrinking waterrequirement>= 0.05 mg / Lthere is at least a... chlorine dioxide residual of 0.05 mg / Lat all times and at all locations within the distribution system, where there is a daily flowhigh
#P042chemicaloperationalmandatorySecondary disinfection minimum combined chlorinedrinking waterrequirement>= 0.25 mg / Lwhere monochloramine is used, a combined chlorine residual of 0.25 mg / Lat all times and at all locations within the distribution system, where there is a daily flowhigh
#P043chemicalhealthmandatorySecondary disinfection maximum chlorine dioxidedrinking waterrequirement<= 0.8 mg / Lshould not exceed... 0.8 mg / L when measured as chlorine dioxideat any time and at any location within the distribution systemhigh
#P044chemicalhealthmandatorySecondary disinfection maximum combined chlorinedrinking waterrequirement<= 3.0 mg / Lshould not exceed... 3.0 mg / L when measured as combined chlorineat any time and at any location within the distribution systemhigh
#P045physicaloperationalmandatoryMembrane filtration treated turbiditydrinking waterrequirement<= 0.1 NTUmeet the performance criterion for filtered water turbidity of less than or equal to 0.1 NTUin 99% of the measurements each monthhigh
#P046physicaloperationalmandatorySlow sand filtration treated turbiditydrinking waterrequirement<= 1.0 NTUmeet the performance criterion for filtered water turbidity of less than or equal to 1.0 NTUin 95% of the measurements each monthhigh
#P047physicaloperationalrecommendedCartridge and bag filtration treated turbiditydrinking waterrequirement<= 0.2 NTUNormally, the filter should meet the performance criterion for filtered water turbidity of less than or equal to 0.2 NTUin 95% of the measurements each monthhigh
#P048designtreatmentmandatoryUV dose for surface water and GUDIdrinking waterrequirement>= 20 mJ / cm2two stage primary disinfection process consisting of UV light (UV reactor’s 254 nm-equivalent UV pass through dose of at least 20 mJ / cm2) combined with chemical disinfectionsurface water or GUDI where disinfection alone is approved by the Directorhigh
#P049operationalreportingmandatoryFree chlorine residual analyzer calibration limitdrinking waterrequirement0.05 mg / Lcalibrated at a frequency necessary to ensure appropriate operation of the analyzer within a quality control band of plus/minus 0.05 mg / Lat a chlorine concentration up to and including 1.0 mg / Lhigh
#P050physicalaestheticrecommendedAesthetic turbidity limit after filtrationdrinking waterrequirement< 5.0 NTUFor aesthetic reasons, however, it is recommended that turbidity levels be maintained below 5.0 NTUwhere turbidity is solely due to oxidation or chemical precipitation downstream of filtrationhigh
#P051designoperationalmandatoryGUDI watertight casing depthdrinking waterrequirement>= 6 metresA drinking-water system that obtains water from a well... that does not have a watertight casing that extends to a depth of at least 6 metres below ground level.Deeming a system as GUDI (Ground water under direct influence of surface water)high
#P052operationaloperationalmandatoryGUDI flow rate thresholddrinking waterrequirement0.58 litres per secondA drinking-water system that is not capable of producing water at a rate greater than 0.58 litres per second and that obtains water from a well, any part of which is within 15 metres of surface water.Determining GUDI status based on well proximity and flow capacityhigh
#P053chemicaltreatmentmandatoryMinimum free chlorine percentage of total chlorinedrinking waterrequirement> 80 %In this case... the application of chlorine should be such that the resulting free chlorine residual, at the end of the primary disinfection process, comprises more than 80% of the total chlorine residualWhere ammonia and other nitrogenous substances are present in the influent water and secondary disinfection is requiredhigh
#P054physicaltreatmentguidelineGeneral treated water turbidity goaldrinking watertreatment_goal< 0.1 NTUWhere possible, the filtration system should be designed and operated to reduce turbidity levels as low as possible, with a goal of treated water turbidity of less than 0.1 NTU at all times.Applicable to all filtration technologieshigh
#P055physicaloperationalguidelineSlow sand filtration raw water turbidity limitdrinking waterrequirement< 10 NTUGenerally, the use of a slow sand filtration process is limited to raw water supply sources (or influent water after pretreatment) having turbidity of less than 10 NTUDesign limitation for slow sand filtrationhigh
#P056chemicaloperationalguidelineDistribution system free chlorine residual targetdrinking watertreatment_goal0.2 mg / LThe recommended optimum target for free chlorine residual concentration in a water distribution system is 0.2 mg ⁄ L at a pH 8.5 or less.Secondary disinfection targethigh
#P057chemicaloperationalguidelineDistribution system combined chlorine residual targetdrinking watertreatment_goal1.0 mg / LThe recommended optimum target for combined chlorine residual for systems designed to operate with chloramination is 1.0 mg ⁄ L at all locations within the distribution systemSecondary disinfection target for chloramination systemshigh

D Definitions (11)

Req ID Category Name Context Confidence
#D001directA point source that discharges pollutants to waters of the United States, such as streams, lakes, or oceans.high
#D002indirectA facility that discharges pollutants to a publicly owned treatment works (municipal sewage treatment plant).high
#D003LEDslight emitting diodeshigh
#D004TTOTotal Toxic Organicshigh
#D005NAICSNorth American Industrial Classification Systemhigh
#D006E&ECElectrical and Electronic Componentshigh
#D007Electronic crystalscrystals made from quartz, ceramics and other materialshigh
#D008Luminescent materialsmaterials used as coatings in fluorescent lampshigh
#D009Cutting and slicingCrystals are cut or sliced using diamond blade saws or slurry saws. Water can be used for cooling and lubrication and to carry away removed material.high
#D010Lapping or polishingMechanical grinders and chemical etchants are used to remove surface oxides and to provide a smooth surface. Water can be used for cooling and lubrication and to carry away removed material.high
#D011Cleaning, rinsing and degreasingRemoval of etchants, photoresist material, stripping solutions and acid and alkaline solutions from materials after various processing and production steps.high