The U.S. Army’s Cold Regions Research and Engineering Laboratory, or CRREL, sits on soil in Hanover, N.H. that's been contaminated by a toxic chemical no longer in use. Trichloroethylene, or TCE, was used for years as a coolant at the facility and has leaked into the soil. If it migrates into water and air it can cause serious health problems. So the Army Corps of Engineers has come up with a way to treat it – and, they hope, eventually to remove it.
An air filter whirs in one of CRREL’s many low, sprawling buildings on this tightly guarded complex as three environmental experts share ideas about how to keep TCE from polluting the air workers breathe here.
Lawrence Cain, a health risk assessor for the Army Corps of Engineers, says TCE has been associated with increased risk for some cancers and immune diseases. Pregnant woman are especially vulnerable to the non-cancer effects.
“It’s virtually anybody coming to work here that is exposed to vapors,” he explains. “There are some places in the building that people are exposed; you can measure vapor levels, and there are other areas in the building where you get non-detects. You can’t detect anything,” he says.
Using advanced technology, the Army Corps says it has been able to pinpoint where TCE could be entering buildings. They have installed an exhaust system similar to fans used to remove radon. But the environmental engineers don’t want to merely treat or re-route this chemical. They would like to remove it. So Daniel Groher, remediation engineer, has been piloting a method that sucks TCE out of the soil, before it can do any harm indoors.
“It’s been an interesting test,” Groher says. “We’re actually still in the middle of it because we got part way into it and the concentrations were so high that we didn’t have enough material to treat the TCE that we were pulling out of the ground. So we had to stop it, and then the winter came. We'll start it up again probably in a month or so.”
The treatment method involved carbon filters. But treating it that way is costly, so Groher hopes another system will work even better.
“Cool it. You chill the air to really low temperatures and you condense all the TCE and you end up with liquid that you put in a barrel and take it away,” Groher says.
Army Corps spokesman Darrell Moore insists workers are safe from TCE contamination, and that neighboring buildings, including a day care center and middle school, have also, to date, passed environmental tests.
Chilling the stuff, he says, is ideal at the Cold Regions Lab, which has the technology in-house. Whatever removal method wins out, Army Corps spokesman Darrell Moore insists workers are safe, and that neighboring buildings, including a day care center and middle school, have also, to date, passed environmental tests.
“Yes, there is an issue; yes, there is a concern. However, we are managing it, and we are monitoring on a daily basis. [A] very intense monitoring program, probably one of the most intense in the country,” Moore says.
Moore leads a tour into rarely seen underground rooms where big blowers send TCE through carbon filters and then outdoors.
“This is one of our systems right here, this one here is a more conventional system,” Moore says, pointing to large orange tanks.
"Carbon — they’re filled with carbon,” Groher adds.
Given all this effort to remove this chemical from the labs, you might guess that TCE is now banned by federal regulators. Not so. It’s also used as a de-greaser that can still be found in products on hardware store shelves. But these engineers say it’s not something they’d put in their shopping carts.
