Testing the waters: Do Regina's asbestos-cement water mains pose a risk?

Snaking beneath Regina's streets are 600 kilometres of water mains built with asbestos-cement.

That's about 60 per cent of some 1,000 kilometres of the mains that deliver water to homes around the city.

Increasingly, some scientists and communities are questioning the wisdom in having drinking water flowing through pipes constructed from asbestos fibres.

At one end of that debate is experts like U.S. public health researcher Dr. Arthur Frank, who advocates stringent testing because of the potential risk he believes asbestos, a cancer-causing fibre, poses generally, and quite possibly in those pipes. Frank thinks federal and municipal governments in Canada need to better "protect the health and well-being of Canadians."

On the other side of the debate Health Canada says there's no risk, stating in its guidelines there's "no evidence of adverse health effects from exposure through drinking water."

It's that advice on which Regina and other Canadian cities rely.

Testing drinking water

The Leader-Post dug into the issue looking at what, if anything, western Canadian cities do about their asbestos-cement water mains.

Regina is one of only two cities — along with Edmonton — among 13 in western Canada that tests drinking water samples for asbestos fibres. Regina's asbestos-cement mains are under older areas of the city, dating back to the 1940s and built under subdivisions developed through to the 1980s.

City workers test for asbestos fibres once per year, always at the same location — 1109 14th Ave., three blocks east of the General Hospital and directly south of Maple Leaf Park.

The results, posted on Regina's website, show the presence of asbestos fibres in 2016, 2017 and 2018 samples. Each sample contains less than 0.18 mg per litre. The 2019 sample, which measures fibres by the millions in one litre of water, shows zero fibres present.

The webpage where those results are posted says Regina's drinking water is safe, as does Kurtis Doney, the city's director of water, waste and environment.

"We've done a fair bit of testing regarding asbestos concrete pipe to ensure that it continues to provide safe drinking water to residents," he said. "Our objective is to follow the provincial and federal guidelines."

Asked why the city started testing for asbestos in 2016, Doney said it "decided to test all water parameters as per Health Canada guidelines to meet best practice. So we do it every year since 2016. We will be doing it in 2020 and beyond."

'If we don't test, we can't find it'

Meanwhile, EPCOR, Edmonton's power and water operator, last tested for asbestos fibres in 2018, taking samples from 14 different testing sites in the city.

"Our testing found no chrysotile or amphibole asbestos fibres in Edmonton's drinking water. We plan to repeat this monitoring again in 2023," the company said in an email to the Leader-Post. The company said it "provides clean, safe drinking water to customers in Edmonton and surrounding areas."

Dr. Frank, the U.S.-based public health researcher, contends both cities' sparse testing methods amount to irresponsible government leadership.

"It reminds me of my current (United States) president, heaven help us, who says 'the problem is we're doing too much testing. If we didn't test we wouldn't have such a high rate of (COVID-19).'

"This is the same thing: 'If we don't test, we can't find it.' And one test a year in one location doesn't answer it," he said.

Frank has been studying asbestos and its effects on people for the past 50 years at New York's Mount Sinai Medical School and at Philadelphia's Drexel University. Over the past 40 years, he has testified in U.S.-based legal cases, representing workers injured by asbestos.

"I'm an occupational physician … I've seen hundreds, if not thousands, of X-rays of asbestos-exposed individuals over my career," he said.

Engineering doctoral candidate Brett Snider says there's no disputing the fact asbestos fibres are leaching into North America's drinking water supplies.

He's nearly finished his PhD dissertation at the University of Guelph, studying water mains' degradation in Canadian and American cities.

"Over the last 40 years, (asbestos-cement pipes are) leaching the calcium hydroxide which also frees up some of these asbestos fibres, so it's leaching into the water," he said.

His research has found "increased pipe failures for these asbestos-cement pipes," particularly in the western U.S. and in British Columbia.

Health impacts need further research: Snider

Snider is not comfortable saying what the health impacts of that leaching may or may not be. "That's the kind the question that still needs to be further researched."

Of the cities contacted by the Leader-Post, nine — Regina, Saskatoon, Prince Albert, Moose Jaw, Weyburn, Swift Current, Medicine Hat, Calgary and Edmonton — cited Health Canada regulations that don't require municipalities to test for asbestos fibres in drinking water. Estevan didn't provide data to the Leader-Post.

Four cities — Winnipeg, Brandon, Lethbridge and Red Deer — confirmed they too don't test water samples for asbestos, either referencing provincial guidelines or none at all.

There's plenty of media coverage about the cancers caused by inhaling asbestos fibres; there's relatively little about potential harms from ingesting them in drinking water.

Federal policy on regulating asbestos

Health Canada says a guideline value for asbestos in drinking water is "not necessary," since there's no "adverse" health impact. The statement appears in a multi-chart document called Guidelines for Drinking Water Quality on the federal department's website.

Different sections of the guidelines have been published and updated over the last 41 years, starting in 1979 with chloride. The most recent updates in 2019 were for chemical elements like copper, lead and manganese.

Asbestos was first listed in the document in 1989 and reaffirmed in 2005. The guideline says a common source of asbestos in water is "decay of asbestos-cement pipes."

Compared to the U.S, Canada's federal policy falls behind in regulating asbestos fibres in citizens' drinking water.

In 1992, 28 years ago, the U.S. Environmental Protection Agency (EPA) enacted enforceable regulation requiring public drinking water systems be at or below a maximum level of asbestos contamination: Seven million asbestos fibres per litre (MFL) in a given water sample.

The EPA's National Primary Drinking Water Regulations say the potential effect from long-term exposure to asbestos fibres is "increased risk of developing benign intestinal polyps (growths)." The fibres can contaminate drinking water by "decay of asbestos cement in water mains."

The sources Health Canada uses in its drinking water guidelines are — like asbestos-cement water mains — old. All sources were published before the 1990s; 26 of 27 were published in the 1970s or 1980s; one was published in the 1960s.

Health Canada response

Health Canada spokesman Andre Gagnon says his department has studied "new scientific data on asbestos in 2009, 2013 and 2018, including studies evaluated by … U.S. EPA."

Despite citing the newer data, not part of the federal department's publicly-posted guidelines, Gagnon said Health Canada still thinks "there is little evidence suggesting a causal relationship between asbestos ingestion and cancer."

He declined the Leader-Post's ask for an interview with a member of Health Canada and could not account for the divergent guidelines reached by Health Canada and the U.S. EPA.

There is little evidence suggesting a causal relationship between asbestos ingestion and cancer.- 

Citizens and governments outside of Canada have opted for more proactive approaches.

In 2019, concerned citizens and local councillors in Cranleigh, U.K. lobbied their privately-owned water supplier to replace all asbestos-cement mains, according to the Financial Times. The town of approximately 12,000 people south of London had 14.2 km (29 per cent) of asbestos-cement mains.

Unlike Health Canada, the Texas state government isn't so quick to draw conclusions about ingesting asbestos.

On the Frequently Asked Questions webpage for its asbestos program, Texas' Department of State Health Services writes, "The health effects from oral asbestos exposures are unclear. In some areas where the residents are exposed to asbestos fibres in the drinking water, cancers of the esophagus, stomach, and intestine may be a greater concern. After reviewing the scientific evidence from human experience and animal testing; however, health authorities are still unsure of asbestos links to cancer in the digestive system."

It says humans' digestive systems "can be exposed to asbestos fibres from drinking water and mucous cleared from the lungs."

Gagnon says Texas' health department reviewed the same 2009, 2013 and 2018 studies that Health Canada did for its own conclusions about ingesting asbestos.

The City of Regina says its drinking water is "treated with relatively high hardness and alkalinity, which forms a barrier on the interior surface of (asbestos-cement) water pipes and thus protects pipe from degradation and prevents the leaching of asbestos fibres into potable water."

Swift Current, with 72.73 per cent of its water mains made of asbestos-cement, had a similar response: "(The city) actively controls the pH (acidity or alkalinity) in our source water, which, in turn, creates a natural barrier inside our pipe system that helps prevent lead and other elements from leaching off of pipes and into the water supply."

Snider, the Engineering PhD candidate, agrees such practices reduce water's aggressiveness, "thus less leaching/degradation of (asbestos-cement) pipe."

But he says "a better indicator would be to look at the trend in pipe breaks. Are the number of (asbestos-cement) pipe breaks per year increasing, especially longitudinal (length-wise) breaks (which tend to occur due to weakened pipes)? If so this likely suggests these pipes are continuing to degrade."

Pipe replacement program

For now Regina is continuing with its pipe replacement program. City workers go underground to replace asbestos-cement pipes that are intact but have a high-break history with PVC pipes, Doney confirmed.

He said the program will "proactively replace pipes that have broken in the past to reduce the number of water main breaks we will see in the future."

As of Aug. 25, the city has replaced 22 km, or 3.67 per cent, of its asbestos-cement mains since 2015.

Frank doesn't expect to see high rates of cancer in locales with exposure to asbestos fibres in drinking water. "But there is a risk. If you get lots and lots of people drinking asbestos-contaminated water, somebody is going to get a cancer, and in most cancers, colon cancer is very common," he said.

He also warned of a latency period, between exposure to asbestos and the development of cancer, anywhere from 10 to 40 years later.

Snider underscored the need for more research on links between ingesting asbestos and digestive tract cancers.

"I don't think we can kind of just say that one way or another that it's totally safe. It's something that needs further research for sure."

By the numbers:

14: Cities contacted by the Leader-Post for their data about asbestos-cement water mains: Winnipeg, Brandon, Regina, Weyburn, Estevan, Moose Jaw, Swift Current, Saskatoon, Prince Albert, Medicine Hat, Lethbridge, Calgary, Red Deer, Edmonton.

75.77: Highest percentage of asbestos-cement water mains, in Weyburn: 59.1 km of 78 km are made with asbestos-cement; Swift Current is close with 72.73 per cent (152 km of 200 km).

1.25: Lowest percentage of asbestos-cement water mains, in Calgary: 66.623 km of 5,309.22 km of mains are made with asbestos-cement; Brandon's water main system has 2.87 per cent of asbestos-cement (8.4 km out of 293 km).

29.93: Percentage of Saskatoon's water main system with asbestos-cement (352 km out of 1,176 km).

10: Maximum length in micrometers (also called microns) an asbestos fibre can be while present in U.S. drinking water, determined by the EPA.

1,000,000,000: Number of micrometres in one kilometre.

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