BASE TO DIG INTO ITS PAST CLEANUP OF TOXIC TRENCHES TO BEGIN.

Byline: Jim Skeen Staff Writer

EDWARDS AIR FORCE BASE - Excavation work is expected to begin next week on four filled-in trenches that were part of a World War II chemical warfare storage yard.

In a $4.5 million cleanup effort, work crews will dig up an estimated 4,000 cubic yards of soil and debris buried in the trenches, located next to a dormitory and near heavily traveled Rosamond Boulevard.

Base officials do not know what is buried in the trenches, but they suspect the trenches were used to dispose of empty containers and unusable or unneeded chemicals.

``It's not acceptable not knowing what's in the trenches,'' said Rebecca Hobbs, the project manager.

The 1.6-acre site was used as part of a chemical warfare material storage yard that was operated in the 1940s.

If procedures of the time were followed, any empty containers would have been doused in kerosene, crushed and set on fire prior to being buried.

``Hopefully, that (crushed containers) is what we'll find,'' said Gary Hatch, spokesman for the base Environment Management Office.

The trenches were 150 to 160 feet long, 15 feet wide and 10 feet deep, and are spaced about 35 feet apart.

One end of the trenches is within a few feet of a $10.6 million, 136-person dormitory that opened in 1998. The trenches are also within walking distance of where 800 airmen live, officials said.

Desert Citizens Against Pollution leader Lyle Talbot, at one time a member of an Edwards citizen advisory board, lobbied in the late 1990s for the excavation.

``The chemicals were 'buried and forgotten' over 50 years ago and it came back to haunt them,'' Talbot said.

A key element of the excavation project is an 80-foot by 50-foot containment building that will be moved on rails along the path of the excavation work. The building will be moved a total of about 11 times during the project.

Using fans and an air filtration system, the containment building will be kept under negative pressure to keep any possible contaminants from escaping.

Crews using a backhoe will dig up 15-foot by 15-foot square areas during the day and backfill with clean dirt at night.

The Air Force is planning to haul the debris to a disposal site inside the base's precision impact range area, a range used for weapons testing. The proposed disposal site was used for disposing of targets.

If any intact chemical containers are found, they will be turned over to the U.S. Army Technical Escort Unit. The unit handles chemical and biological warfare materials for the Defense Department.

The unit would first transfer the material to a secured interim facility on base. The material would later be sent to the appropriate disposal facility, officials said.

A mobile office trailer at the site will serve as an information center featuring a video monitoring system that will be available for base workers wanting to see the work in progress. Hobbs dubs the video system ``all trench TV, all the time.''

The storage yard was closed in September 1946. There are no records of materials being removed from the site. A memo issued by the commanding officer at the time indicated that the chemical warfare section was short-handed in the effort to destroy all excess chemicals on hand.

``This lack of personnel at the end of the war suggests that proper procedures may not always have been followed in destroying the chemicals,'' according to an engineering evaluation and cost analysis prepared for the excavation project.

Military records show that mustard gas, a chemical agent called lewisite and tear gas were sent to Edwards during the years the yard was in operation.