Tanapag PCB remediation project resumes

The U.S. Army Corps of Engineers’ Tanapag PCB Remediation Project has resumed work following a break for the holiday season.

The most recent phase of the project being done in Tanapag Village began in August. Since then, more than 12,000 cubic yards of soil contaminated by polychlorinated biphenyl, commonly referred to as PCBs, has been removed from Cemetery No. 2 and other Tanapag village sites and stockpiled in nearby containment cells.

Environmental Chemical Corporation of Aiea, Hawaii, a leading company in the PCB-remediation field, is doing the work under contract with the Corps.

Although a conclusive link to the Department of Defense has not been established, the Corps’ Honolulu Engineer District is overseeing the project as part of the Department of Defense’s Formerly Used Defense Sites program.

The contamination resulted when PCB fluid leaked from capacitors that were moved to various sites in Tanapag Village by unknown individuals decades ago.

The Department of Environmental Quality reported the presence of the capacitors to the U.S. Environmental Protection Agency in 1988.

The U.S.-EPA asked the Army whether it could use U.S. Department of Defense funds to remove the PCBs from the soil since the capacitors had apparently been used at the U.S. Army’s Kwajalein Atoll military installation in the 1960s.

The Army agreed to fund the removal of the PCBs and the Corps began the soil cleanup project in 1991. The current project is the third phase of the cleanup.

The quantity of contaminated soil being removed in this phase of the cleanup has proven to be much larger than the originally estimated 4,000 cubic yards.

Excavation and stockpiling of the soil is expected to continue for at least two more months. All work is being done with U.S.-EPA oversight under the provisions of a U.S.-EPA administrative order issued in accordance with the Resource Conservation and Recovery Act.

Meanwhile, Environmental Chemical Corporation is constructing equipment to treat the contaminated soil when the excavation and stockpiling is completed.

The treatment that the Corps proposes to use is a thermal desorption process that has been successful at other PCB-contaminated soil cleanup projects undertaken through the U.S.-EPA’s Superfund program.

Unlike furnace-type equipment, the system heats and cleanses the material without combustion. This prevents the formation of potentially dangerous chemical wastes that sometimes result when PCBs are burned in an ordinary incineration process.

The remediation equipment will be shipped to, and assembled and tested in, Tanapag. The current schedule calls for the soil cleanup to begin in May. The soil-treatment process is expected to take about six months.