Common 'Wet Sock' Pipe Repair Method Releases Dangerous Chemicals

Aug 8, 2017

About a year ago, Purdue engineering professor Andy Whelton started a Kickstarter campaign to fund his research on what's known as cured in place pipe, or CIPP, in part because he’d had to use some of his own cash to keep it going.

"So literally what happens is when they cure the materials, they drag this basically a damp, wet, chemical-filled sock into the pipe. They cap it, and then they heat it,” Whelton says.

That sock expands to fill the pipe, and after a few hours, all the interior cracks are covered by a new layer of material. Half of all water pipe repair in the U.S. is now done this way. Whelton opens a red picnic cooler that has what looks like pieces of concrete inside it, each encased on their own heavy plastic bag.

“I mean, you can feel it. It can’t get any harder than that," Whelton says as he pounds on the hardened material. "And it’s fiberglass with resin inside it. And one of the main chemicals that they use in the process is called styrene – which is a known human carcinogen.”

Whelton had begun investigating CIPP after receiving several calls from people who lived or worked near sites where it was being installed. That styrene creates a strong odor, which is one of the telltale signs so-called “trenchless pipe repair” is going on nearby.

In fact, news reports from across the U.S. and Canada include tales of the smell.

The companies installing CIPP say the odor comes from styrene, and dissipates quickly. But Whelton says there was little data to show that’s all it was.

“We’re caring about when they’re pumping in that steam," Whelton says.  "And the odor gets really, really strong when they’re pumping that in around the workspace, or there’s this white stuff floating around in the air, What is that? What are the exposures?”

That white plume also became a focus of the research. Whelton and his team visited several sites and placed air quality monitors in and around the chemical clouds to capture samples of emissions that the professor now definitively says are “not steam.”

Video his team took at a site on the Purdue University campus shows workers in orange vests, but no other safety equipment, as they walk in and around a plume flowing from an open manhole.

Whelton also submitted public records requests to several American cities he knew had used CIPP. Some, such as St. Louis and Los Angeles, sent back the data he requested. Others, such as Chicago, said they couldn’t comply because a private firm handles repairs for the city and isn’t subject to public records laws.

All that was months ago. When we caught up with Whelton on the eve of his findings being published, he was less equivocal about what his tests showed.

“Based on what we’ve seen, the steam-cured CIPP should not continue to be used as it’s being used today," Whelton says. "Changes have to be made.”

The paper, published in the journal Environmental Science and Technology Letters, shows more than a dozen chemicals are present in the chemical plumes, which Whelton says includes other known carcinogens besides styrene.

But Gerry Muenchmeyer, who’s now a CIPP consultant and has previously been on the board of the National Association of Sewer Service Companies, or NASSCO (the trade group that advocates for trenchless repair technology) says he has his doubts.

“You know, I’ve seen a lot of reports quite frankly, and many of them have been faulty,” Muenchmeyer says. “I mean the industry tests this all the time and we know exactly what the concentrations are and whatnot. And the information was totally impossible – it couldn’t happen."

Ironically, both Muenchmeyer and Whelton use the same rationale for their arguments – that their data is better.

“I have no problem with looking at issues like this, but the data has to be accurate; the data has to be correct," Muenchmeyer says. "Otherwise, you’re putting stuff out there that is just another scare tactic that has no basis. If it has basis, then something should be done about it, I agree with you.”

“There have been two studies that I’ve been made aware of that’ve been made public by industry, but they have narrowly focused on certain chemicals," Whelton says. "They have ignored other issues and they actually didn’t declare most of their methods about how they did the study, so you can’t actually determine if the data is even valid or representative of anything.”

Whelton says his team has perhaps the first reliable information about what’s emitted from steam-cured CIPP sites. Both from what he’s measured, and what he’s personally seen.

“On a work site that we visited, and we were collecting a sample of the uncured resin, one of the students was helping me and I was handling the uncured resin fabric, my nitrile gloves, plastic gloves, dissolved away in about 30 seconds to a minute,” he says.

Whelton says he’s expecting pushback from the industry. But he’s hopeful the National Institute for Occupational Safety and Health, or NIOSH, will issue a notice about CIPP upon seeing his findings. That would give him a powerful ally in his push to reform a system that’ll be very busy in the coming years as most states grapple with the fact they’ve let their roads, bridges and pipes rot.

“One of the reasons I got into civil/environmental engineering was because I wanted to help people," Whelton says. "And that’s how I’ve kind of tried to lead my professional career – can I help people? Because the workers out there are well-meaning individuals that are rebuilding the infrastructure for us. And the least we can do is make sure that their health is protected.”

Whelton hopes his research leads industry leaders to seek him out so they can work on solutions together – solutions he’s already developing in his lab.

Until then, he sees a Wild West-style landscape lacking regulations – a problem he hopes to fix. And, as he says, the first cowboy through the door usually takes the most arrows.