Lead is a heavy metal that can be found naturally in the environment and has many industrial uses including use in water pipes, solder, and metal fixtures.
No level of lead exposure is considered safe, and Health Canada advises to strive to achieve levels of lead in drinking water that are as low as reasonably possible.
In March 2019, Health Canada lowered the national drinking water guideline for lead to 0.005 mg/L, which is half of the previous guideline, in recognition of its linkage to many adverse health effects in both adults and children.
Water supplied by Alberta’s public and semi-public water systems is virtually lead-free at source prior to distribution, but lead can be introduced downstream through lead-containing pipes or fixtures. Lead pipes were largely phased out in Canada in the 1950s, but were still allowed in the National Plumbing Code until 1975, and tin-lead solder was allowed until 1986. Higher levels of lead in drinking water are more likely to be found in older buildings and neighbourhoods.
Bottles and submission forms for testing lead in drinking water canbe obtained at the laboratory from 8:00 am to 4:30 pm.
In addition to reducing the drinking water lead guideline, Health Canada changed the point for compliance measurement to be at the customer’s tap, rather than within the upstream drinking water distribution system. Moving forward, Alberta Environment and Parks (AEP) requires Alberta waterworks providers to consider impacts of household plumbing for their provision of safe drinking water. AEP expects waterworks facilities to develop and implement a lead management program starting January 1, 2020, which includes testing of representative customer water supply lead concentrations (at tap), identification and removal of lead sources (such as lead service lines), and communication to customers of techniques to reduce lead exposure.
AEP requires all testing for lead in drinking waters to be conducted by approved laboratories. The ALS laboratories in Edmonton and Calgary hold ISO 17025 accreditation for the analysis of lead in water and are approved by AEP for this testing program.
Health Canada has provided sampling protocols that are to be used when testing for the following:
- Home Owners and Home Based Child Care Providers
- Large Buildings*, Schools, and Child Care Centers
Sampling Supplies:
- 1x 1L Wide-mouth Plastic Bottle
- 2 x 125-mL Wide-mouth Plastic Bottles (from each tap, fountain, or other fixture used for drinking or cooking)
Sampling Instructions for Random Daytime Sampling:
- Sample at the cold water tap used most often for drinking and food preparation, usually the kitchen tap. Other taps, fountains, or fixtures used for drinking or cooking water may also be investigated. Prioritize testing of older fixtures and fixtures commonly used for infants or children.
- If the kitchen faucet has a point of use (POU) filter, collect from another non-filtered fixture also used for drinking water, or remove the POU filter.
- Collect samples without intentional prior flushing; no stagnation period is prescribed (random stagnation or flushed conditions reflect typical usage).
- Do not remove or clean the aerator before sampling.
- Collect samples using an uninterrupted moderate flow rate (4 to 6 L/minute, where possible).
- Fill all sample bottles completely.
- Record Sampling Location (e.g. building, fixture), Date, and Time collected on each sample bottle and sampling form. If two sample bottles are collected, fill one immediately after the other and label as bottles #1 and #2.
- Return to lab as soon as possible for testing.
Sampling for Elevated Values
Health Canada has recommended using the 30-minute Stagnation Method (30MS-2L) when sampling to investigate elevated lead levels
- Sampling Supplies: 2 x 1L wide-mouth plastic bottle per fixture.
- Flush the cold water tap for 2-5 minutes at moderate flow.
- Turn off the water tap and stop all water use for 30 minutes. Ensure no water is used in the residence (including flushing toilets) during that time.
- Collect two 1-litre samples, one immediately after the other, at moderate flow rate (4 to 6 L/minute) from each fixture being investigated. Label the bottles as first and second sampling for the sampling location.
- Instruct the lab whether to test each bottle separately or using a composite sample to obtain an average result (if composite sampling is done, follow-up testing of the individual samples should be done if the average lead result is > 5 ug/L).
