For more than twenty years, when Columbia’s pipes need to be replaced, the city has often rehabilitated them instead through a method scientists say could put workers in danger.
The city is planning a $9.2 million project starting in 2025 to rehabilitate aging pipes in central and western of Columbia. Rather than replacing the pipes, the city is using a cheaper method called cured-in-place (CIPP) pipe relining.
It’s a method that doesn't require digging up old pipe and replacing it. Instead, the insides of pipes are coated with a resin, which is then heated with steam to create a hard lining.
But the coating, often styrene-based polyester and vinyl ester resin, holds chemicals that evaporate along with the steam.
Those chemicals, including styrene, can be carcinogenic, Purdue Engineering Professor Andy Whelton said.
He wrote a study observing how CIPP relining practices in Indiana and California led to noxious fumes with the potential to harm workers.
“When you are exposed to the chemical plume, you could potentially experience ear, nose and throat chemical exposure symptoms,” Whelton said. “Dizziness, nausea... It’s an acute chemical exposure, what you’re generally most concerned about.”
The Centers for Disease Control and Prevention, on its website, says CIPP relining can lead to workers developing respiratory diseases, suffering headaches and tiredness among other ailments.
Whelton said that using steam to rehabilitate sewer lines, it is “inevitable” that chemicals enter the environment, which can cause people to get sick.
Jason West, Communications and Outreach supervisor for the City of Columbia Utilities, said CIPP’s effects had never been an issue that’s been brought up to them.
“The biggest complaint, if you will, that we’ve gotten is just the smell that is associated with the process, that it smells like burnt coffee,” West said.
Whelton said the smell could be an indication of health risk exposure, but it can’t be determined without testing.
West said the city works with third party contractors that meet federal work safety requirements. However, after being presented with new science, he said it’s something the city will take into consideration for future projects.