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Document ID ca-dgsmmccsi-2022-12-16 Title Draft guidance on sampling and mitigation measures for controlling corrosion: Supporting information URL https://www.canada.ca/en/health-canada/programs/consultation-draft-guidance-sampling-mitigation-measures-controlling-corrosion/supporting-information.html Jurisdiction /ca Subdomain(s) Drinking water, Water treatment, Distribution and infrastructure Language en Status completed Analyzed at 2026-03-19 09:55:51.087098+00:00 Relevance Draft technical guidance on sampling and mitigation for water system corrosion.

68 Qualitative 41 Quantitative 50 Definitions

Q Qualitative Requirements (68)

Req ID	Category	Intent	Legal Status	Name	Subdomain(s)	Context	Conditions	Confidence
#Q001	monitoring	health	guidance	Assess Contaminant Exceedances	drinking water	It is important to assess whether these contaminants will be present at concentrations that exceed those considered safe for human consumption.	When evaluating corrosion in distribution systems	high
#Q002	prohibition	health	recommended	Discoloured Water Assessment	drinking water	Discoloured water should not be considered safe to consume or treated as only an aesthetic issue.	During discoloured water (red water) events	high
#Q003	monitoring	health	recommended	Discoloured Water Sampling and Maintenance	drinking water	Instead, the occurrence of discoloured water should trigger sampling for metals and potentially additional distribution system maintenance (Friedman et al., 2016).	Occurrence of discoloured water	high
#Q004	administrative	health	mandatory	Potable Water Components Compliance	drinking water	Under the NPC, components (i.e., fittings) used for potable water applications must comply with the relevant standards for plumbing fittings (NRCC, 2015).	When selecting components for potable water applications	high
#Q005	administrative	health	mandatory	Plastic Pipe Compliance	drinking water	Under the NPC, all plastic pipes must comply with the CSA B137 series of standards for plastic pipe, which require that pipes and the associated fittings comply with the NSF/ANSI/CAN Standard 61 (NSF International, 2020a) requirements for leaching of contaminants.	When using plastic pipes in distribution or premise plumbing	high
#Q006	monitoring	operational	recommended	Monitoring During Treatment Process Changes	drinking water	Changes made to the treatment process, particularly those that affect water quality parameters such as pH, alkalinity and oxidation-reduction potential (ORP); blending; and change of water supply should be accompanied by close monitoring in the distributed water (Schock, 2005).	When treatment processes are changed	high
#Q007	prohibition	operational	recommended	Prohibition of Corrosion Indices for Control Assessment	drinking water	Corrosion indices should not be used to assess the effectiveness of corrosion control programs, as they provide only an indication of the tendency of calcium carbonate to dissolve or precipitate.	When assessing effectiveness of corrosion control	high
#Q008	monitoring	unknown	mandatory	Appropriateness of Materials in Simulators	drinking water	The use of new plumbing material in simulators (e.g., pipe rigs) must be deemed to be appropriate for the corrosion of concern.	When using simulators or pipe rigs to evaluate corrosion	high
#Q009	monitoring	operational	mandatory	Duration of Coupon Insert Tests	drinking water	The duration of the test must allow for the development of corrosion scales, which may vary from 3 to 24 months, depending on the type of metal examined (Reiber et al., 1996).	When conducting coupon insertion testing	high
#Q010	monitoring	operational	mandatory	Conditioning Period for Pipe Rig Systems	drinking water	The conditioning period must allow for the development of corrosion scales, which may vary from 3 to 24 months, depending on the type of metal examined.	When using pipe rig systems	high
#Q011	operational	treatment	recommended	Caution for Treatment Adjustments	drinking water	Adjustments of the pH or alkalinity or the use of corrosion inhibitors to control lead, copper or iron levels in drinking water should be done with caution.	When adjusting pH, alkalinity, or using corrosion inhibitors	high
#Q012	operational	treatment	recommended	Corrosion Control Pilot Studies	drinking water	Pilot studies should be conducted to determine the effectiveness of the corrosion control method chosen for the particular conditions prevailing in the distribution system.	Prior to implementing a new corrosion control method	high
#Q013	monitoring	operational	recommended	Rigorous Full-Scale Monitoring for Corrosion Programs	drinking water	Thus, rigorous full-scale monitoring should also be conducted before, during and following the initiation or optimization of a system’s corrosion control program.	During initiation or optimization of a system’s corrosion control program	high
#Q014	administrative	health	recommended	Encouragement of Full Lead Service Line Replacement	drinking water	Generally, utilities should strongly encourage consumers to replace their portion of the lead service line when they are undertaking to replace the public portion.	When utilities are replacing the public portion of a lead service line	high
#Q015	treatment	treatment	recommended	Identify Effective Treatments for LSL Replacements	drinking water	Utilities should, therefore, identify the corrosion control treatment which would be effective for all lead service line configurations.	When dealing with lead service line replacements	high
#Q016	operational	health	recommended	Flushing After LSL Replacement	drinking water	When undertaking lead service line replacement, appropriate flushing should be conducted after the replacement, and debris should subsequently be cleaned from the screens or aerators of outlets (Health Canada, 2019a).	After lead service line replacement	high
#Q017	operational	health	recommended	Initial Mitigation Following LSL Replacement	drinking water	Extensive initial flushing by the consumer should be encouraged and other mitigation measures, such as point-of-use filtration, public education and/or weekly or biweekly sampling until lead levels stabilize, should be considered by the utility.	Following a lead service line replacement event	high
#Q018	monitoring	health	recommended	Water Quality Monitoring Post-LSL Replacement	drinking water	The water quality at the consumer’s tap should be monitored closely following both full and partial lead service line replacement for several months after replacement.	For several months following full or partial lead service line replacement	high
#Q019	reporting	health	recommended	Communication on Aerator Maintenance	drinking water	The importance of regularly cleaning outlet aerators should be communicated to consumers to ensure that any lead-containing particles are removed as part of ongoing maintenance (Health Canada, 2019a).	Ongoing consumer communications	high
#Q020	design	operational	recommended	Dielectric Fitting Use	drinking water	When connecting two dissimilar metals, a dielectric fitting should be used to prevent galvanic corrosion (Wang et al., 2012; Clark et al., 2014; AWWA, 2017b).	When connecting two dissimilar metals in partial replacement scenarios	high
#Q021	operational	operational	recommended	Copper Pitting Mitigation Tools	drinking water	Given the variety of water quality, microbiological and flow condition factors that can cause copper pitting, utilities should consider using tools such as those found in Sarver et al. (2011).	To avoid or mitigate copper pitting	high
#Q022	design	health	recommended	Use of Certified Drinking Water Materials	drinking water	Health Canada recommends that, where possible, water utilities and consumers use drinking water materials that have been certified as conforming to the applicable NSF/ANSI health-based performance and lead content standards (NSF International, 2020a,b)	When selecting materials for distribution and plumbing	high
#Q023	corrective_action	health	recommended	Response to Discoloured Water Events	drinking water	Therefore, discoloured water events should trigger distribution system maintenance actions, such as systematic unidirectional flushing of the distribution system, to ensure that all particles are flushed out before the water reaches the consumer (Vreeburg, 2010; Friedman et al., 2016).	Discoloured water episodes	high
#Q024	operational	operational	recommended	Disturbance Minimization Strategy	drinking water	Strategies to minimize physical and hydraulic disturbances should also be developed.	General distribution system maintenance	high
#Q025	treatment	treatment	recommended	Orthophosphate Application Locations	drinking water	For systems using orthophosphate for corrosion control, the inhibitor should be applied at all entry points and a consistent residual concentration should be maintained throughout the distribution system to promote the stability of phosphate-based scales (Friedman et al., 2010).	For systems using orthophosphate for corrosion control	high
#Q026	treatment	operational	mandatory	pH Adjustment for Reverse Osmosis Water	drinking water	Therefore, the product water pH must be adjusted to avoid corrosion issues in the distribution system such as the leaching of lead and copper (Schock and Lytle, 2011; U.S. EPA, 2012).	When using reverse osmosis (RO) treatment processes	high
#Q027	treatment	health	recommended	Use of Certified Additives and Inhibitors	drinking water	Health Canada recommends that, where possible, water utilities and consumers choose drinking water additives, such as corrosion inhibitors, that have been certified as conforming to the applicable NSF/ANSI health-based performance standard or equivalent.	When choosing drinking water additives and inhibitors	high
#Q028	operational	health	recommended	Best Practices for System Flushing	drinking water	Extensive initial flushing by the consumer should be encouraged and utilities should follow best practices for flushing (AWWA, 2017b).	Following a lead service line replacement or construction disturbance	high
#Q029	monitoring	health	recommended	Monitoring Before Recommending Flushing	drinking water	Therefore, utilities should conduct the appropriate monitoring to ensure that flushing is an appropriate measure before recommending it to consumers.	Before recommending flushing to consumers	high
#Q030	reporting	health	recommended	Communicate Flushing Limitations	drinking water	They should also ensure appropriate flushing and communicate its practical limitations (Katner et al., 2018).	When communicating flushing measures	high
#Q031	monitoring	health	recommended	Retain Aerator During Sampling	drinking water	It is important to ensure that sampling is done with the aerator or screen in place so that potential particulate lead contributions may be detected.	When collecting samples at the tap	high
#Q032	operational	operational	recommended	Regular Flushing of Larger Systems	drinking water	Best practice also calls for the flushing of larger distribution systems on a regular basis, especially in dead ends, to get rid of loose corrosion by-products and any attached microorganisms.	Regular maintenance for larger distribution systems	high
#Q033	administrative	health	recommended	Certification of Point-of-Use Filtration	drinking water	Health Canada does not recommend specific brands of drinking water treatment devices, but strongly recommends that consumers look for a mark or label indicating that the device or component has been certified by an accredited certification body as meeting the appropriate NSF/ANSI drinking water treatment standards.	When consumers seek point-of-use or drinking water treatment devices	high
#Q034	monitoring	health	mandatory	Monitor Pipe Coatings Use	drinking water	The use of coatings must be carefully monitored, because they can be the source of several water quality problems (Schock and Lytle, 2011).	When utilizing pipe linings or coatings	high
#Q035	design	health	recommended	Compliance Standard for Coatings	drinking water	Coatings should meet the requirements of ANSI/NSF/CAN Standard 61 and the relevant AWWA standards.	When utilizing pipe linings or coatings	high
#Q036	operational	health	recommended	Rehabilitation Alternative Caution	drinking water	Caution should be exercised when considering this rehabilitation option as any failure may unknowingly put the consumer at risk of lead exposure.	When considering in-situ lining or epoxy coatings	high
#Q037	monitoring	unknown	mandatory	Controls in Monitoring Programs	drinking water	Monitoring programs must, therefore, include controls for the causes of variability in order to obtain results that are representative and reproducible (Schock, 1990a; AwwaRF, 2004; European Commission, 1999).	In residential monitoring programs	high
#Q038	monitoring	unknown	recommended	Tap Selection and Flow Rate for Residential Sampling	drinking water	For residential monitoring programs, sampling considerations should include ensuring that sampling is done at the kitchen tap, with the aerator or screen on and at flow rates typically used (approximately 4 to 5 L/min) by consumers (van den Hoven and Slaats, 2006).	For residential monitoring programs	high
#Q039	corrective_action	health	recommended	Domestic Sampling Failure Investigation	drinking water	When the failure is in a sample from a tap in domestic premises or other premises which are not a public building, no further samples are required but a comprehensive investigation should be undertaken to establish if lead is present in the pipe work belonging to the homeowner.	When a failure occurs in a domestic/non-public premise	high
#Q040	monitoring	unknown	recommended	Seasonal Sampling Consideration	drinking water	Sampling programs should be conducted throughout the year to take into account seasonal effects on lead variability.	General sampling program requirements	high
#Q041	monitoring	unknown	recommended	Cold Water Tap Sampling Requirement	drinking water	Sampling should be conducted at the cold water tap in the kitchen or other appropriate location where water is used for drinking or food preparation.	Locating proper sampling tap	high
#Q042	monitoring	unknown	recommended	Sampling Bottle and Aerator Protocol	drinking water	Regardless of the protocol used, all samples should be collected in wide-mouth sample bottles and without removing the aerator.	During sample collection	high
#Q043	monitoring	unknown	recommended	Tier 1 RDT Sampling Method	drinking water	Samples should be collected directly from the consumer’s tap without prior flushing; no stagnation period is prescribed to better reflect consumer use (without removing the aerator or screen).	For Tier 1 RDT sampling	high
#Q044	corrective_action	health	recommended	Action Following Tier 1 Exceedance	drinking water	When more than 10% of the sites (defined as the 90th percentile) have a lead concentration greater than 0.005 mg/L (MAC/goal), it is recommended that utilities take corrective measures, including conducting additional sampling following the Tier 2 sampling protocol.	When greater than 10% of sites exceed 0.005 mg/L lead	high
#Q045	monitoring	unknown	recommended	Tier 1 30 MS Flow Rate Application	drinking water	In consideration of this, 30 MS sampling should be conducted at medium to high flow rates (> 5 L/min) to capture particulate lead release for the sampling protocol.	For Tier 1 30 MS sampling	high
#Q046	reporting	health	recommended	Reporting Exceedance Avoidance Information	drinking water	If fewer than 10% of sites (defined as the 90th percentile) have lead concentrations above 0.005 mg/L, utilities should provide customers in residences with information on methods to reduce their exposure to lead.	When fewer than 10% of sites exceed 0.005 mg/L	high
#Q047	monitoring	unknown	recommended	Follow-Up Sampling of Consumer Measures	drinking water	It is also recommended that utilities conduct follow-up sampling for these sites to assess the effectiveness of the corrective measures undertaken by the consumer.	Following consumer corrective measures for lead exposure	high
#Q048	monitoring	unknown	mandatory	Tier 2 Sampling Obligation	drinking water	Tier 2 sampling is required only when the first-tier sampling identified more than 10% of sites (defined as the 90th percentile) with lead concentrations above 0.005 mg/L (SG).	When >10% of sites in Tier 1 have lead > 0.005 mg/L	high
#Q049	monitoring	unknown	recommended	Tier 2 Minimum Sampling Sites for Small Systems	drinking water	For smaller systems (i.e., serving 500 or fewer people), a minimum of 2 sites should be sampled to provide sufficient lead profile data for the system.	For systems serving 500 or fewer people under Tier 2	high
#Q050	monitoring	unknown	recommended	Characterization of High-Risk Sites	drinking water	Since the volume of sample needed to obtain water that has been stagnant in the lead service line will depend on the plumbing configuration at each site, utilities should conduct a broad characterization of the types of high-risk sites to estimate if collection of 4 1-L samples will be sufficient.	Before conducting profiling sampling	high
#Q051	monitoring	unknown	recommended	Retain Aerator for Non-Residential Tier 1	drinking water	To ensure that representative samples are collected, the aerator or screen on the outlet should not be removed prior to sampling.	Non-residential sampling protocol	high
#Q052	corrective_action	health	recommended	Non-Residential Exceedance Corrective Actions	drinking water	If the lead concentration exceeds 0.005 mg/L (MAC) at any of the monitoring locations, corrective measures should be taken.	If lead exceeds 0.005 mg/L in non-residential buildings	high
#Q053	monitoring	unknown	recommended	Non-Residential Stagnation Period	drinking water	Therefore, first-flush samples should be collected following a minimum period of stagnation of 8 h, but not greater than 24 h, so that they are representative of the longer periods in which outlets are not used for drinking during most days of the week in a non-residential building.	For non-residential building sampling	high
#Q054	corrective_action	health	recommended	Non-Residential Interim Protective Measures	drinking water	When the SG of 0.005 mg/L is exceeded, interim corrective measures should be taken to protect the health of sensitive populations in situations with exposure patterns, such as those found in non-residential buildings.	When SG of 0.005 mg/L is exceeded in non-residential buildings	high
#Q055	reporting	health	recommended	Notification of Building Occupants	drinking water	Occupants of the building and other interested parties such as parents should be informed of the results of any sampling conducted in the building.	Following sampling in non-residential buildings	high
#Q056	monitoring	health	mandatory	Resampling of Exceeding Outlets	drinking water	Water fountains and cold water outlets exceeding the Tier 1 system goal are resampled in the same year and in the same season.	For outlets exceeding Tier 1 goal	high
#Q057	corrective_action	health	recommended	Tier 2 Exceedance Actions	drinking water	When the Tier 2 lead concentrations exceeds 0.005 mg/L, immediate corrective measures should be taken, the lead sources should be determined and remediation measures should be implemented.	When Tier 2 samples exceed 0.005 mg/L	high
#Q058	corrective_action	unknown	recommended	Interpretation of Results Against Plumbing Profile	drinking water	The results of Tier 1 and Tier 2 sampling should be interpreted in the context of the plumbing profile so that an assessment of the lead contributions can be made and the appropriate interim and long-term corrective measures can be taken.	When interpreting Tier 1 and Tier 2 non-residential results	high
#Q059	monitoring	unknown	recommended	Entry Point Sampling in Non-Residential Buildings	drinking water	It is recommended that at each monitoring event, samples be taken from an outlet close to the point where the water enters the non-residential building.	At each monitoring event for non-residential building	high
#Q060	monitoring	unknown	recommended	Flushing Prior to Entry Point Sample	drinking water	Ideally, samples should be collected after an appropriate period of flushing so that they are representative of water from the service line and from the water main.	When collecting entry point samples for a building	high
#Q061	administrative	reporting	recommended	Development of Non-Residential Sampling Plan	drinking water	The number of monitoring sites that should be sampled in a non-residential building should be based on the development of a sampling plan.	Before conducting non-residential monitoring	high
#Q062	monitoring	unknown	recommended	Creation of Building Plumbing Profile	drinking water	A plumbing profile of the building should be completed to assess the potential for lead contamination at each drinking water fountain or cold drinking water or cooking outlet.	As part of non-residential sampling plan	high
#Q063	monitoring	health	recommended	Prioritization of Fountains and Outlets	drinking water	The sampling plan should prioritize drinking water fountains and cold water outlets used for drinking or cooking based on information obtained in the plumbing profile, including, but not limited to, areas containing lead pipe, solder or brass fittings and fixtures, areas of stagnation and areas that provide water to consumers, including infants, children and pregnant people.	When finalizing building sampling plans	high
#Q064	monitoring	health	mandatory	Extensive Outlet Sampling Duty	drinking water	Authorities that are responsible for maintaining water quality within non-residential buildings will need to do more extensive sampling at individual outlets based on the sampling plan developed for the building.	For authorities responsible for maintaining water quality in non-residential buildings	high
#Q065	monitoring	unknown	recommended	Aerator Handling and Flow Rate for Kitchen Taps	drinking water	When sampling at kitchen taps in non-residential buildings, the aerators and screens should be left in place, and typical flow rates should be used (approximately 4 to 5 L/min).	Sampling at kitchen taps in non-residential buildings	high
#Q066	monitoring	unknown	recommended	Flow Rate for Water Fountains	drinking water	However, for other types of outlets, such as water fountains, lower flow rates are typical and should be used when sampling.	Sampling at water fountains	high
#Q067	monitoring	unknown	recommended	Flushing After Valve Operation	drinking water	After opening a shut-off valve, outlets should be completely flushed and then allowed to stagnate for the appropriate period of time.	If a shut-off valve is opened prior to sampling	high
#Q068	monitoring	health	recommended	Exposure Assessment Variations	drinking water	Sampling methods used to assess exposure should ideally take these variations into account.	When developing exposure sampling methods	high

P Quantitative Requirements (41)

Req ID	Category	Intent	Legal Status	Name	Subdomain(s)	Limit Type	Limit Value	Context	Conditions	Confidence
#P001	design	health	mandatory	Lead content of solder	drinking water	requirement	<= 0.2 %	The relevant standards, namely ASME A112.18.1/CSA B125.1 and CSA B125.3, limit the lead content of solder to 0.2%	Applicable to components (i.e., fittings) used for potable water applications under the National Plumbing Code.	high
#P002	design	health	mandatory	Lead content of plumbing fittings and materials	drinking water	requirement	<= 0.25 %	To comply with NSF/ANSI/CAN Standard 372... the lead content of components such as plumbing fittings and materials must not contain more than 0.25% lead as a weighted average.	Weighted average limit for compliance with NSF/ANSI/CAN Standard 372.	high
#P003	chemical	health	guideline	Aluminum	drinking water	requirement	2.9 mg/L	The Canadian guideline for aluminum in drinking water is 2.9 mg/L and is based on neurological effects		high
#P004	chemical	treatment	mandatory	Lead (POU device effluent)	drinking water	requirement	< 5 μg/L	For a drinking water treatment device to be certified for the removal of lead, the device must be capable of reducing an influent lead concentration of 150 μg/L (particulate and dissolved) to a maximum final (effluent) lead concentration of less than 5 μg/L	Required for certification of POU devices to NSF/ANSI standards.	high
#P005	chemical	health	recommended	Lead	drinking water	MAC	> 0.005 mg/L	When more than 10% of the sites (defined as the 90th percentile) have a lead concentration greater than 0.005 mg/L (MAC/goal), it is recommended that utilities take corrective measures...	Applies when >10% of randomly sampled sites exceed this level during residential Tier 1 monitoring.	high
#P006	chemical	health	recommended	Lead (Non-residential Tier 1)	drinking water	MAC	> 0.005 mg/L	If the lead concentration exceeds 0.005 mg/L (MAC) at any of the monitoring locations, corrective measures should be taken.	Applies to monitoring in non-residential and residential buildings such as child care centres, schools, and office buildings.	high
#P007	operational	treatment	guideline	Optimal pH for Lead and Copper Control	drinking water	treatment_goal	7.5 - 9.5 pH	Experience has shown that the optimal pH for lead and copper control falls between 7.5 and 9.5.		high
#P008	operational	treatment	guideline	Optimal Alkalinity for Lead and Copper Control	drinking water	treatment_goal	30 - 75 mg/L as CaCO3	The literature appears to indicate that the optimal alkalinity for lead and copper control falls between 30 and 75 mg/L as CaCO3.		high
#P009	operational	treatment	recommended	Orthophosphate Residual Concentration	drinking water	OG	0.5 - 3.0 mg/L (as phosphoric acid)	Typical orthophosphate residuals are between 0.5 and 3.0 mg/L (as phosphoric acid).	Maintained throughout the distribution system through the premise plumbing.	high
#P010	design	treatment	mandatory	POU Filter Influent Lead Challenge	drinking water	requirement	150 μg/L	For a drinking water treatment device to be certified for the removal of lead, the device must be capable of reducing an influent lead concentration of 150 μg/L (particulate and dissolved)...	Standard test condition for NSF/ANSI certification.	high
#P011	operational	aesthetic	recommended	Preferred Alkalinity for Iron Control	drinking water	treatment_goal	> 60 mg/L as CaCO3	Higher alkalinity (> 60 mg/L as CaCO3) is also preferable for the control of iron corrosion, iron level and red water occurrences.		high
#P012	chemical	health	recommended	Lead (Residential Tier 1 Monitoring)	drinking water	MAC	0.005 mg/L	When more than 10% of the sites (90th percentile) have a lead concentration greater than 0.005 mg/L (MAC/goal), it is recommended that utilities take corrective measures.	Applies to system-wide Tier 1 residential sampling.	high
#P013	chemical	health	mandatory	Lead (Non-residential Monitoring)	drinking water	MAC	0.005 mg/L	If the lead concentration exceeds 0.005 mg/L (MAC) at any of the monitoring locations, corrective measures should be taken.	Applies to schools, child care centres, and office buildings.	high
#P014	operational	treatment	guideline	Optimal pH for orthophosphate film formation (Lead)	drinking water	treatment_goal	7 - 8 pH	Solubility models for lead and copper indicate that the optimal pH for orthophosphate film formation is... between 7 and 8 on lead surfaces.	Applies when using orthophosphate for lead corrosion control.	high
#P015	operational	treatment	guideline	Optimal pH for orthophosphate film formation (Copper)	drinking water	treatment_goal	6.5 - 7.5 pH	Solubility models for lead and copper indicate that the optimal pH for orthophosphate film formation is between 6.5 and 7.5 on copper surfaces.	Applies when using orthophosphate for copper corrosion control.	high
#P016	chemical	health	recommended	U.S. EPA Lead Action Level	drinking water	requirement	0.015 mg/L	Utilities had an 80% likelihood of exceeding the U.S. EPA Lead and Copper Rule Action level for lead of 0.015 mg/L.	Benchmark used for evaluating corrosion control effectiveness in utility data surveys.	high
#P017	chemical	health	recommended	U.S. EPA Copper Action Level	drinking water	requirement	1.3 mg/L	No utilities with a pH above 7.8 exceeded the U.S. EPA’s action level for copper of 1.3 mg/L.	Benchmark used for evaluating copper solubility and corrosion control results.	high
#P018	design	health	guideline	Current Brass Lead Content	drinking water	requirement	< 4 %	Historically, most brasses contained between 2% and 8% lead but currently contain less than 4% lead.	Typical content of modern brass alloys used in potable water systems.	high
#P019	operational	treatment	guidance	City of Ottawa pH Selection	drinking water	treatment_goal	9.2 pH units	The City of Ottawa selected a pH of 9.2... to control corrosion.	Operational target selected based on bench- and pilot-scale experimental results.	high
#P020	operational	treatment	guidance	City of Ottawa Minimum Alkalinity Target	drinking water	treatment_goal	35 mg/L as CaCO3	The City of Ottawa selected... a minimum alkalinity target of 35 mg/L as CaCO3... to control corrosion.	Minimum target used in conjunction with pH adjustment.	high
#P021	chemical	health	guideline	EC Directive Aluminum Limit	drinking water	requirement	0.2 mg/L	Aluminum concentrations above the European Community (EC) Directive of 0.2 mg/L were found following installation in very low alkalinity water.	Benchmark cited during field trials of cement mortar-lined pipes.	high
#P022	physical	reporting	recommended	Residential Monitoring Flow Rate	drinking water	requirement	4 - 5 L/min	Sampling considerations should include ensuring that sampling is done... at flow rates typically used (approximately 4 to 5 L/min) by consumers.	Standard flow rate to ensure representative lead concentration samples.	high
#P023	chemical	treatment	guideline	Chloride to Sulphate Mass Ratio (CSMR) Threshold	drinking water	requirement	< 0.58 ratio	A review of lead levels reported by 365 water utilities revealed that higher chloride to sulphate mass ratios (CSMRs) were associated with higher 90th-percentile lead levels. 100% of the utilities with a CSMR below 0.58 met the U.S. EPA’s action level for lead.	Used to assess the risk of lead leaching from plumbing systems.	high
#P024	physical	operational	guidance	Dissolved Oxygen Boundary for Copper Release	drinking water	requirement	< 1 mg/L	Copper levels will initially increase upon stagnation, but only until dissolved oxygen fell below 1 mg/L, after which they dropped significantly.	Stagnant water conditions in copper plumbing.	high
#P025	chemical	aesthetic	guidance	Minimum Alkalinity for Cement Stability	drinking water	treatment_goal	> 55 mg/L as CaCO3	When the alkalinity was greater than 55 mg/L as CaCO3, no water quality problems (pH increases or aluminum leaching) were observed with cement mortar linings.	Applicable to distribution systems using cement-based materials or linings.	high
#P026	operational	treatment	guideline	Optimal Alkalinity for Lead Control (Laboratory)	drinking water	treatment_goal	30 - 45 mg/L as CaCO3	Laboratory experiments also revealed that, at pH 7 to 9.5, optimal alkalinity for lead control is between 30 and 45 mg/L as CaCO3.	Laboratory-determined range for minimizing lead solubility.	high
#P027	operational	reporting	mandatory	Non-residential Tier 1 Stagnation Time	drinking water	requirement	8 - 24 hours	A first-draw 250 mL sample is taken at locations identified... after the water has been stagnant for a minimum of 8 h, but generally not more than 24 h.	Required stagnation period for Tier 1 monitoring in non-residential buildings (schools, daycares).	high
#P028	operational	treatment	guidance	Theoretical minimum lead solubility pH	drinking water	treatment_goal	9.8 pH units	Solubility models based on Pb(II) chemistry show that the lowest lead levels occur when pH is around 9.8.	Theoretical model based on divalent lead solids.	high
#P029	operational	treatment	guidance	Theoretical minimum lead solubility alkalinity	drinking water	treatment_goal	30 - 50 mg/L as CaCO3	According to thermodynamic models, the minimum lead solubility occurs at relatively high pH (9.8) and low alkalinity (30 to 50 mg/L as CaCO3).	Theoretical model for uniform scales of lead minerals.	high
#P030	physical	reporting	mandatory	Residential Tier 1 RDT sample volume	drinking water	requirement	1 L	A 1 L sample is collected randomly during the day from a drinking water tap in each of the residences.	Tier 1 residential monitoring (Option 1).	high
#P031	physical	reporting	mandatory	Non-residential monitoring sample volume	drinking water	requirement	250 mL	A first-draw 250 mL sample is taken at the locations identified in the sampling plan.	Monitoring in schools, child care centres, and office buildings.	high
#P032	physical	reporting	mandatory	Residential Tier 2 sample volume	drinking water	requirement	4 consecutive 1 L samples	Four consecutive 1 L samples are taken at the consumer’s cold drinking water tap... Each 1 L sample is analyzed individually to obtain a profile of lead contributions.	Tier 2 residential monitoring (Option 1 and 2).	high
#P033	operational	reporting	mandatory	Residential Tier 2 stagnation time	drinking water	requirement	>= 6 hours	Four consecutive 1 L samples are taken... after the water has been stagnant for a minimum of 6 h.	Required for Tier 2 b residential monitoring to capture lead service line contributions.	high
#P034	physical	reporting	recommended	Residential 30 MS monitoring flow rate	drinking water	requirement	> 5 L/min	30 MS sampling should be conducted at medium to high flow rates (> 5 L/min) to capture particulate lead release.	Applicable to Tier 1 30 MS (Option 2) monitoring at sentinel sites.	high
#P035	operational	reporting	mandatory	Stagnation duration (30 MS protocol)	drinking water	requirement	30 min	For the 30 MS protocol, samples are collected after the water has been left to stagnate for a fixed period of 30 min.	Fixed period for residential Option 2 or Tier 2a monitoring.	high
#P036	operational	reporting	mandatory	Flushing duration (prior to 30 MS stagnation)	drinking water	requirement	5 min	4 consecutive 1 L samples are taken... after the water has been fully flushed for 5 min and the water has then been left to stagnate for 30 min.	Pre-sampling flush required for 30 MS protocol and Tier 2a residential profiling.	high
#P037	operational	reporting	mandatory	Flushing duration (Tier 2 non-residential)	drinking water	requirement	30 s	A second 250 mL sample is taken after a period of stagnation... followed by a 30-s flush.	Follow-up sample to identify source of lead at specific outlets in schools or daycare centers.	high
#P038	physical	reporting	recommended	Sampling flow rate (non-residential kitchen taps)	drinking water	requirement	4 - 5 L/min	When sampling at kitchen taps in non-residential buildings... typical flow rates should be used (approximately 4 to 5 L/min).	Used for non-residential monitoring to ensure representative samples.	high
#P039	operational	operational	guideline	pH threshold for Zinc corrosion	drinking water	requirement	7.5 pH units	Below pH 7.5, zinc levels increased in drinking water (DIC concentration of 50 mg C/L).	Applicable to systems with galvanized steel pipes.	high
#P040	operational	operational	guideline	pH threshold for Zinc coating removal	drinking water	requirement	10.4 pH units	Waters at pH > 10.4 can be aggressive to zinc and will often remove galvanized coatings.	Waters where zinc hydroxides predominate.	high
#P041	design	treatment	recommended	Minimum study duration for pipe rig systems	drinking water	requirement	6 months	6 months is recommended as the minimum study duration for pipe rig systems to allow for development of corrosion scales.	Applicable when using simulators/simulated systems to evaluate corrosion control strategies.	high

D Definitions (50)

Req ID	Name	Context	Confidence
#D001	corrosion of metallic materials	destruction of a metal by electron transfer reactions	high
#D002	polyvinyl chloride	PVC	high
#D003	National Plumbing Code of Canada	NPC	high
#D004	oxidation-reduction potential	ORP	high
#D005	dissolved inorganic carbon	DIC	high
#D006	chloride to sulphate mass ratios	CSMRs	high
#D007	natural organic matter	NOM	high
#D008	bed volumes	BVs	high
#D009	reverse osmosis	RO	high
#D010	point-of-use	POU	high
#D011	random daytime	RDT	high
#D012	fully flushed	FF	high
#D013	fixed (30-min) stagnation time	30 MS	high
#D014	Bronzes	alloys of copper, tin and zinc, with or without lead	high
#D015	European Community	EC	high
#D016	coefficient of variation	CV	high
#D017	system goal	SG	high
#D018	Stannous chloride	tin chloride	high
#D019	Brasses	alloys of copper and zinc with other minor constituents, such as lead	high
#D020	microbiologically influenced corrosion	results from a reaction between the pipe material and organisms, their metabolic by-products or both	high
#D021	A-C	asbestos-cement	high
#D022	90th percentile	more than 10% of the sites	high
#D023	lead dioxide	PbO2	high
#D024	red brass	Bronzes	high
#D025	Larson Index	ratio of the sum of chloride and sulphate to bicarbonate	high
#D026	tubercles	iron corrosion by-products formed during the corrosion process	high
#D027	red water	discoloured water	high
#D028	full replacement of a lead service line	utility and homeowner portions	high
#D029	partial lead service line replacement	replacing only the utility or consumer’s portion	high
#D030	composite proportional sampling	sampling achieved with a consumer-operated device fitted to the drinking water tap that splits off a small, constant proportion of every volume of water drawn	high
#D031	zone	discretely supplied area	high
#D032	in-situ lining products	consisting of collapsed tubing inserted through small-diameter pipes and then expanded with heat and pressure to seal the pipe interior surface against water contact	high
#D033	passivation	results from the formation of a surface film composed of a Pb(II) hydroxycarbonate or orthophosphate solids	high
#D034	cuprous	Cu(I)	high
#D035	cupric	Cu(II)	high
#D036	ferrous solid scales	FeCO3	high
#D037	tetravalent lead	lead dioxide	high
#D038	electrolyte	solution that will conduct ions between the anode and the cathode	high
#D039	oxidation	anodic dissolution of the metal to produce metal ions and electrons	high
#D040	protective scales	usually created when the metal cation combines with a hydroxide, oxide, carbonate, phosphate or silicate to form a precipitate	high
#D041	MAC	maximum acceptable concentration	high
#D042	cerussite	PbCO3	high
#D043	hydrocerussite	Pb3(CO3)2(OH)2	high
#D044	lead hydroxide	Pb(OH)2	high
#D045	cuprous hydroxide	Cu(OH)2	high
#D046	bronchantite	Cu4(SO4)(OH)6	high
#D047	cupric phosphate	Cu3(PO4)2	high
#D048	tenorite	CuO	high
#D049	malachite	Cu2(OH)3	high
#D050	hydrozincite	the most stable corrosion by-product	high