Water pipe repair method not as safe as previously thought, researchers say

West Lafayette, IN – A common procedure used to repair water pipes can release hazardous chemicals into the air and should be re-evaluated for its risks to workers, the public and the environment, according to researchers from Purdue University.

Cured-in-place pipe repair method involves inserting a resin-impregnated fabric tube into a damaged pipe and curing it with hot water, pressurized steam or ultraviolet light to create a new plastic pipe.

As part of a study, researchers completed air test studies at seven steam-cured CIPP locations in Indiana and California – two sanitary sewer-pipe installations and five storm-water pipe installations. Tests determined that chemical plumes once considered to be steam actually contained organic vapors and compounds – some of them known carcinogens and endocrine disruptors. The results contradict longstanding assumptions about the technology’s safety.

“This technology is being used in 50 percent of all water pipe repairs in the United States,” Andrew Whelton, assistant professor of engineering at Purdue, said in a video. “We need to immediately understand the short- and long-term impacts of these exposures to the workers and possibly to John Public. If there are these types of impacts, we need to institute operational changes or technology changes to protect the workers and protect the public from these exposures.”

The researchers recommend additional research into the CIPP method.

“The CIPP process is actually a brilliant technology,” John Howarter, co-author and assistant professor of engineering at Purdue, said in a July 27 press release. “Health and safety concerns, though, need to be addressed. We are not aware of any study that has determined what exposure limit to the chemical mixture is safe. We are not aware of any study that indicates that skin exposure or inhaling the multi-phase mixture is safe. We also are not aware of any study that has examined the persistence of this multi-phase mixture in the environment.”

In the release, Whelton said that CIPP workers should wear “appropriately thick chemically resistant gloves” while handling chemicals and tubes. Further, workers should notify health officials, not only contractors and engineers, of any odors near CIPP sites as well as related illnesses.

“We have seen evidence that companies and utilities do not understand what materials are created and emitted by CIPP processes or the consequences of exposure,” Whelton said in the release.

The study was published online July 26 in the journal Environmental Science & Technology Letters.