Monday, May 23, 2005	Sioux City, Iowa	WEB EDITION

RAPID CITY, S.D. (AP) -- The Department of Defense says it will continue an environmental cleanup of jet fuel, solvents and other contaminants at Ellsworth Air Force Base, even if the base is closed as the department has recommended.

Ellsworth is a Superfund site. Over the past 10 years, the cleanup ordered by the Environmental Protection Agency has cost the Air Force $61 million.

"The Air Force and the Department of Defense are liable," Pentagon spokesman Glenn Flood told the Rapid City Journal.

There is a long list of contaminants, most of them released into the environment decades ago.

Low-level nuclear waste left over from atomic weapons and small amounts of mustard agent already have been removed. The most prevalent pollutants are petroleum products, including jet fuel and lubricants, and chlorine-based solvents such as trichloroethylene, or TCE, which can cause cancer.

The rest of the cleanup likely will take decades and could cost additional tens of millions of dollars, according to Air Force documents.

The EPA put Ellsworth on its "National Priorities List" in 1990. The Superfund designation included groundwater and soil contamination at 20 sites throughout the base.

The contamination also extends to private land southwest and east of the base.

Ellsworth was on the Defense Department's base-closure list released May 13. Now the future of the base is up the Base Realignment and Closure Commission, the White House and Congress.

In September, Ellsworth will undergo its second five-year EPA review. Remedies are already in place at all 20 of the hazardous sites.

"That's a major milestone," EPA project manager Jeff Mashburn said in a telephone interview from Denver.

Ellsworth is exclusively a B-1B Lancer bomber base, but it opened in 1942 as an Army Air Corps training base for B-17 bomber crews.

The based closed briefly after the war, then reopened as a Cold War base, hosting a succession of missiles, heavy bombers and air tankers.

Almost all of the contamination happened between 1942 and the early 1970s, said Del Petersen, chief of environmental restoration at Ellsworth.

The Air Force began its environmental investigation in 1984, with soil and water sampling and an archive search that included historic photos.

Pictures of gas trucks refueling B-17s revealed the sites of old fuel spills.

Atomic Energy Commission records led investigators to low-level radioactive waste, such as rags used to clean parts for nuclear weapons.

Written records even documented how the Army Air Corps had buried radium-painted, glow-in-the-dark instrument dials.