Underground water pipes have changed a lot over the past 120 years.
This evolution includes wooden staves, then asbestos cement, then ductile iron, and now it’s high density polyethylene.
Across the U.S., there are more than 600,000 miles of asbestos-cement pipe. Public Works Director Tom Wetor said Wrangell has about two and a half miles of that distance. That’s approximately 9% of all water mains. As these old pipes deteriorate, the asbestos can get into drinking water, which causes health problems.
Wetor said the AC pipe isn’t in one continuous line. It’s scattered around town and one of the mains will be replaced next year on McKinnon Street.
“We’ve got a handful of them still left in the ground,” he said. “There’s a portion along Zimovia Highway, from basically Alpine Mini Mart to over by the Public Works office, and down to Case Avenue is one that I know of.”
Wetor said the AC pipe in Wrangell was likely installed between 1955 to 1980. He said it actually holds up better than ductile iron, which was introduced after AC. For example, St. Michaels Street has ductile iron, and it had six water main breaks in five years, which led to recurring potholes. The city replaced those pipes and rebuilt the street this year.
Wetor said some AC lines have broken over the five years he’s been director. The ones under McKinnon Street haven’t had issues yet, though the city is planning to replace them next year when they rebuild the road.
“McKinnon Street’s just old and anything that is AC is generally going to predate the ductile iron water mains and so my guess is that was installed pre-1980,” he said.
Asbestos cement greater than 50 years old is pushing it
Dr. Arthur Frank, a Clinical Professor of Public Health and Professor of Medicine at Drexel University in Philadelphia who has studied the health effects of asbestos for over 50 years, said that’s pushing it.
“The lifespan of asbestos cement pipes is generally about 50 years,” he said. “I wouldn’t be surprised if they start breaking on you one of these days, and that’s going to put more stuff into the water supply.”
“More stuff” meaning asbestos fibers. Inhaling asbestos poses the highest cancer risk, but ingesting it can potentially cause health problems, too, including some gastrointestinal cancers.
“If you could get monies to replace those with non-asbestos pipes, you’d be doing everybody a great service,” Frank said.
Still, he said Wrangell’s risk is relatively low, since AC piping here is only about 10% of the system.
Municipality does not test for asbestos in drinking water on regular basis
The U.S. Environmental Protection Agency does set limits on asbestos in drinking water. However, Wetor said the municipality doesn’t regularly test for the microscopic fibers.
He said, “I think if we had reasons to test for, if we were suspicious that for some reason it was breaking loose, then yes, we would definitely test for that.”
Frank said asbestos can leach into water over time, even without a pipe break.
He said, “For what it’s worth, if there’s anybody that’s particularly concerned, the usual water filtration systems that people have in their homes, either a home system or a Brita filter, will take most of them out.”
Wetor said Wrangell wants to replace the AC pipes, but cost is a major barrier.
“It’s definitely on our radar,” he said. “Sometimes it’s kind of a challenge of where we are seeing the biggest blowouts versus what can we get funding for versus what do we want to pay for out of pocket.”
The St. Michaels Street pipe replacement and rebuild cost $1.3 million for just 300 feet of road.
“It would bankrupt the city multiple times over again”
City officials expect McKinnon Street, at 280 feet, to cost even more because of asbestos disposal, a dense network of fiber-optic cables crews will have to navigate and the street is wider.
“For us to do the miles and miles of roads that we have here in town, it would bankrupt the city multiple times over again to address that kind of stuff,” Wetor said. “So it’s something that we’re chipping away at, and that’s part of the reason why we’ve gone with the approach that we did here this year and last year (by working on one street per year).”
Wetor said the McKinnon Street project is expected to be completed at the end of next summer.
