Health Canada sets new guideline for lead in drinking water

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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.

graph of dietary lead intake canada
The average dietary intake of lead (µg/kg body weight/day) by Canadians of all ages has decreased approximately eight-fold between 1981 and 2000. The graph also illustrates that since the 2000, the average dietary intake of lead by Canadians of all ages has remained stable at about 0.1 µg/kg body weight per day. Graphic Credit: Health Canada

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.

lead-in-drinking-water-infographic
Click to enlarge. Infographic credit: Health Canada

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.

For more information on lead in drinking water, visit these information pages set up by the Canadian Water and Wastewater Association and Health Canada.

2 COMMENTS

  1. More that 15 years ago I contacted CWWA because Drinking Water Guidelines were treated anorganic constituents of surface water or groundwater as contaminants. Simply, CWWA put the anorganic constituents in the same “bag” as biological and organic constituents. I agree that those biological and organic constituents are contaminants and they naturally do not belong to drinking water. But anorganic constituents should be treated as natural part of water. Water is not just H2O and from its origin, flow and accumulation it is picking gases as oxygen and CO2 and dissolving soil/rock minerals. Natural water has some mineralization (or dissolved solids) and they are not harmful. They give water a taste and humans need them.
    Current treatment of the anorganic constituents is resulting into a false assumption that the best drinking water is the one with zero content of all constituents. Only pH should be between 6.5 and 7.5. Please, check labels on bottled water (for an example).
    DWG should clearly state, that anorganic matter is a natural part of water and those anorganic constituent belong there. And what is necessary it to add “Recommended Concentration Range” for the anorganic constituents or at least for TDS.

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