Health Canada published revised guidelines concerning lead in Canadian drinking water on March 8, 2019. The most significant change is the reduction of the maximum allowable concentration (MAC) of lead in drinking water, from 0.01 mg/L (set in 1992) to 0.005 mg/L.
According to Health Canada, since the phase-out of leaded gasoline and the reduction of airborne lead pollution, food and drinking water are the primary sources of lead exposure to adults. However, even at low concentrations, lead causes negative health effects, with infants and children the most sensitive to its harmful effects.
Health Canada’s lower MAC of lead is based on recent research that indicates that lead can have harmful effects at extremely low levels, said the Canadian Water and Wastewater Association (CWWA). At 0.005 mg/L, Canada now has one of the lowest targets for lead in the world.
In a communique, the CWWA said it fully supports the revised drinking water guidelines and the goal of eventually eliminating all lead from drinking water. To help municipal water professionals speak to the new drinking water guidelines, the CWWA has put together a fact sheet and speaking notes containing helpful information about lead in drinking water.
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However, Health Canada’s guidelines are not regulations, so it is up to Canadian provinces and territories to determine how, and if, they will adopt the lower levels for lead.
How does lead get in drinking water?
According to the CWWA, water that is treated and distributed in municipal systems is generally lead-free. However, drinking water can come into contact with lead in the “service lines”, which are the pipes that connect each property to the water main. Lead can also be found in household plumbing materials, such as lead pipes, brass fixtures, and lead soldering.
While Canadian municipalities began phasing out the use of lead in “service lines” to properties in the 1960s, the National Plumbing Code permitted the use of lead until 1975 and lead solder until 1986. Restrictions on lead content in brass fittings are much more recent, with the newest definitions set in 2013.
Removing lead from drinking water
According to the CWWA, the first goal is to eliminate lead from water systems by removing and replacing lead service lines. Communities across Canada have endeavoured to strategically replace lead service lines at appropriate opportunities, such as during road reconstruction.
While this replacement process can be expensive and take many years, the CWWA said that communities are making great progress through these efforts and continue to identify and remove any remaining lead service lines from their municipal systems.
A less expensive, but still effective alternative to replacement, is to line the interior of service lines with a material that blocks lead from entering the water supply.
Health Canada has published a list of simple actions to reduce exposure to lead from drinking water. These include:
- Flush out your pipes before consuming the water
- If water has been sitting in your pipes for several hours, run the tap until it’s cold (about one minute) before drinking or cooking with it.
- Only use cold tap water for drinking or cooking, since hot water increases the leaching of lead and other metals from your plumbing.
- Clean your taps monthly
- Every month, inspect the aerators or screens at the tap.
- Clean out any debris, as this will remove any particles that may contain lead, and inspect more frequently.
- Even if you do not find debris, continue to inspect monthly.
- Replace brass fittings
- Brass faucets and valves can contain some lead. These can be replaced with fittings that are certified to the standard on low lead content.
- As a temporary solution, a household water filter at the tap can effectively remove lead from your water.
- The filter must be installed and maintained properly, or it could become ineffective.
- Test your water for lead before installation and during use to confirm the filter is working.
- Make sure that any device you purchase is certified to the NSF International standard for removal of lead.