US Air Force,
San Antonio: Air Force officials plan to use an innovative technology to clean up contamination at a former plating shop at the former Kelly Air Force Base in Texas. Speeding up the cleanup process at former bases fulfills an Air Force-wide goal of accelerated environmental resolution, and allows Air Force officials to more quickly turn over ownership of the former base to the Port Authority of San Antonio for redevelopment.
Officials will be using electric resistive heat, or ERH, that sends electric currents 30 feet below the ground surface to heat soil and groundwater and accelerate cleanup. The heat then creates steam and vaporizes the contaminants so they can be captured and treated. The vapors are collected and treated underground before reaching the surface, which eliminates risk of possible exposure to the contaminants.
“The technology heats the soil to about 90 degrees to speed up the vaporization process,” said Luis Medina, the technical program manager. “The chemicals underground cannot vaporize with hot, summer temperatures alone. Temperatures underground are considerably lower than above ground. Additionally, the contaminants are shielded by 6 inches of asphalt.”
The Air Force will install the new system under a parking lot constructed after the demolition of Bldg. 301 to extract volatile organic compounds. The former plating shop was demolished after the installation closed. A permeable reactive barrier was put in place to prevent the contamination from migrating off base.
ERH is similar to soil vapor extraction, which is currently used at the former Kelly AFB to clean up similar affected areas. Air Force officials discovered ERH works as effectively as SVE, but at a faster rate.
“We chose this method of cleanup over more traditional methods because we wanted to minimize disruptions to the tenant and finish up as quickly as possible,” said Bill Hall, Air Force Real Property Agency environmental program manager.
To date, Air Force officials have successfully cleaned up and closed 76 percent of the environmental sites using approved regulatory processes and standards. Electric resistive heat will be the latest technology the Air Force has implemented in the environmental restoration program at the former Kelly AFB.
