EDWARDS TO CLEAN TRENCHES STRUCTURE TO CONTAIN TOXINS.

Byline: Jim Skeen Staff Writer

EDWARDS AIR FORCE BASE - In one of Edwards Air Force Base's most elaborate and visible environmental cleanup efforts, a temporary containment structure on moveable rails will be erected near a dormitory in preparation for excavation of trenches containing unknown debris.

Preparations are expected to begin this month for excavation work of four filled-in trenches that were part of a World War II chemical warfare storage yard.

``Having debris trenches that close to a dorm is unacceptable, and not knowing what is in those trenches is unacceptable,'' said base spokesman Gary Hatch.

The project is expected to cost between $6.3 million and $8.4 million.

Base officials do not known what is buried in the trenches. It is suspected they were used to dispose of empty containers and unusable or unneeded chemicals.

The site preparation is expected to take about 45 days and the excavation work will take 60 to 90 days.

The trenches were 150 to 160 feet long, 15 feet wide and 10 feet deep. They 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.

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.

A mobile office trailer will be located at the site to serve as an information center. The information center will have a video monitoring system that will be used by the contractor conducting the cleanup and will be available for base workers wanting to see the work in progress.

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

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. 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.

As much as 2,000 cubic yards of soil and debris will be removed from the trenches.