Hill Air Force Base testing indoor air for contaminants from groundwater vapor
As summer gives way to the fall/winter heating season, Hill Air Force Base will resume its testing of indoor air from homes and businesses in communities where historical practices at the base resulted in the chemical contamination of shallow groundwater.
While that groundwater is not used for drinking, residents in pocket areas of Weber and Davis counties potentially could be exposed to chemicals like trichloroethylene, or TCE, via vapor intrusion.
Vapor intrusion occurs when vapor-forming chemicals migrate from a subsurface source into an overlying building. Shallow plumes — groundwater bodies containing contaminants — exist in specific areas of Sunset, Clinton, Layton, Riverdale, Roy and South Weber.
Since 2001, the air has been tested in some 3,220 homes both inside and outside of the affected areas via Hill’s Indoor Air Sampling Program, or IAP. Additional testing was conducted prior to the IAP’s official launch.
Contaminant vapors were found in just 10% of locations tested. However, Mark Roginske — IAP manager at Hill — told the Standard-Examiner that there are still 358 locations where the air has never been sampled/tested.
And while he understands resident concerns about privacy, he says steps have been taken to make the sampling process as noninvasive as possible.
“Some people don’t want a stranger — even if they’re from the Air Force, or maybe because they’re from the Air Force — into their homes. So, we now have a process where they would prepare the sampling device there on the doorstep, tell the resident a good place to locate it and then the resident would take that and hang it in their houses,” Roginske said.
“They’re about the size of a pencil, and we put them in the lowest occupied space in the building. … We hang these in the basement and we leave them in there for 24 to 26 days. They just kind of passively sample the air over that time, and people can just go about living their lives. They’re out of the way.”
He added that the Air Force pays for all of the indoor air sampling, as well as mitigation systems.
TCE is used as a metal degreaser and also to make refrigerants. It also was used as a surgical anesthetic and inhaled analgesic before the Food and Drug Administration banned its use in 1977.
Exposure to the chemical has been linked to an increased risk of kidney cancer, non-Hodgkin’s lymphoma and other health conditions.
The Air Force has established risk-based action levels, or RBALs — contaminant levels at which taking action to prevent groundwater vapors from entering homes/businesses is recommended — for TCE and other chemical contaminants.
“If we have a detection within 24 to 26 days above (the RBALs), and that risk would be a health risk, then we would recommend that the owner of the building allow us to put in what we call a vapor intrusion mitigation system, which acts very similar to a radon mitigation system,” Roginske said.
Roginske describes the mitigation system as a PVC pipe, connected to a fan, that travels underneath a foundation and “sucks the TCE vapors out.”
For more detailed information on the IAP, groundwater contamination and maps of affected/sampling areas, go to https://www.hill.af.mil/IAP/.
People living or operating businesses in areas eligible for testing also have or will receive IAP information packets in the mail.