Air Force plans changes to Johnston Atoll cleanup
By Jan TenBruggencate
Advertiser Science Writer
The Air Force has proposed a series of changes to its toxic materials cleanup program at Johnston Atoll, the former chemical weapons storage and disposal site that lies about 700 miles southwest of Honolulu.
The atoll is a national wildlife refuge, but has been used for a range of military activities, including nuclear explosion tests, storage of Agent Orange and the storage and disposal of chemical munitions such as nerve gas and blister agents.
The chemical weapons disposal plant has been closed and dismantled, but the island continues to be plagued by a range of contamination issues associated with half a century of military use, including one area of radioactive soil from two nuclear-rocket mishaps in the 1960s, petroleum products in the soil at various locations, PCB compounds, dioxin, and copper and lead residue.
The military has placed a coral debris cap on the low-level radioactive soils at Johnston Island, one of four islands within the atoll. The EPA has expressed concern about eventual erosion of the coral fill cap material, but the agency has no direct control over the military's handling of the radioactive site. More highly radioactive soils have been excavated and removed.
Among the proposed remedies for other toxic compounds are the excavation of PCB-contaminated soils, which would be shipped to the Mainland for disposal. The soils containing dioxin are being heat-treated. Soils with unacceptably high levels of lead and copper would be excavated and shipped off-island.
Some petroleum contamination will be addressed by digging up contaminated soil, some of which is 4 to 7 feet deep, and spreading it out in a layer 12 inches deep. The soil would be fertilized and irrigated to promote the activity of bacteria that naturally break down oil products.
Additionally, there are requirements for a program that tests soils, lagoon sediment and fish for toxic materials.
The Environmental Protection Agency, which issues permits for the cleanup, has opened a public comment period through May 7.
"These proposed modifications will allow the Air Force to clean up contamination on the island and close the base safely for people and wildlife living on and around Johnston Atoll," said Arlene Kabei, the EPA's associate director for hazardous waste management in the Pacific Southwest.
For information on the proposals, call the EPA's Honolulu office at 541-2710. Send comments to: EPA Region 9, ATTN: Vern Christianson, 75 Hawthorne St., San Francisco, CA 94105, or e-mail christianson.vern@epa.gov.
An EPA public meeting on the changes is scheduled for 6:30 p.m. April 13 at the Washington Middle School auditorium.
Reach Jan TenBruggencate at jant@honoluluadvertiser.com or (808) 245-3074.
