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Editorial: Lead guideline update

June 19, 2017  By Colleen Cross

Canada’s Federal-Provincial-Territorial Committee on Drinking Water recently released a report on lead in drinking water with an eye to updating the Guidelines for Canadian Drinking Water Quality. Comments were taken from the public until March 15.

The report, entitled “Lead in Drinking Water,” proposes lowering the maximum acceptable concentration (MAC) for total lead in drinking water to 0.005 mg/L (5 µg/L) from the current guideline of 0.010 mg/L (10 µg/L) “based on a sample of water taken at the tap and using the appropriate protocol for the type of building being sampled. Every effort should be made to maintain lead levels in drinking water as low as reasonably achievable (or ALARA).”

The report provides updated data and information related to exposure to lead in Canada, to analytical methods and to treatment approaches available at the municipal and residential scales, the government said in a news release.


What is the current status of the proposed guideline? The Water and Air Quality Bureau, which is part of Health Canada, told Ground Water Canada in an email that the guideline document still needs to be revised to take comments into consideration, approved through two federal-provincial-territorial committees and then published.

After that, the bureau said, it will be up to provinces and territories to decide whether or not to adopt the guideline, incorporate it into regulations, enforce it and set a timeline for doing so.

It’s reassuring to see the federal government take action to limit lead in our drinking water supply. The current summary table lists the reasons behind the MAC as effects on the intellectual development and behaviour of infants and children under six years, along with anemia, central nervous system issues and ill effects in pregnant women on their unborn babies.

These and other damaging effects came to the forefront in Flint, Mich., in January 2016, when, due to insufficient water treatment, more than 100,000 residents were potentially exposed to high levels of lead in their drinking water. A federal state of emergency was declared in January 2016 and Flint residents were instructed to use only bottled or filtered water for drinking, cooking, cleaning, and bathing. A year-and-a-half and a nearly $100-million EPA settlement later, water quality has returned to acceptable levels but residents are still using filtered and bottled water and likely will be until 2020.

Nevertheless, a new Canadian guideline will likely mean changes for the water well drilling and related industries.

According to the “Lead in Drinking Water” report, there may be an economic effect on the testing side. For private wells, it says – and this is based on historical water quality data – a changed MAC will result in an exceedance of the limit that could raise the costs associated with analytical testing and treatment.

Interestingly, the committee report says that although most often found through testing at the tap, lead has also occasionally been found in drinking water as a result of the weathering of certain rock formations into the ground water. In 2006, a public health advisory was issued to rural City of Hamilton residents located above the Niagara Escarpment whose drinking water supply was obtained from a drilled well. Residents were advised that there was a potential for high lead levels in some wells due to naturally occurring lead in the bedrock.

Well regulations and infrastructure policy also may change. Finally, we’ll need to pay attention to the new analytical and treatment protocols outlined in the report.

While we applaud the tighter guideline, it’s important the industry stay informed and ready for its ripple effects.

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