CLEANUP YIELDING NO CONTAMINATION.

Byline: Jim Skeen Staff Writer

EDWARDS AIR FORCE BASE - Excavations in a World War II-era chemical warfare storage yard are turning up concrete and metal debris, but no hazardous materials, officials said Monday.

In a $4.5 million cleanup effort, work crews are digging up an estimated 4,000 cubic yards of soil and debris from four filled-in trenches next to a dormitory and near heavily traveled Rosamond Boulevard.

``We haven't found any contamination,'' said Gary Hatch, spokesman for the base's environmental management office. ``We've found cement and small metal debris not related to chemical-warfare materials.''

The trenches were 150 to 160 feet long, 15 feet wide and 10 feet deep, and are spaced about 35 feet apart. They were covered over decades ago after the storage yard was closed, and base facilities have been built around them.

The cleanup crews have found long concrete slabs, about 6 feet wide and 11 inches thick, that run the length of the trenches. On either side of the slabs are keyways, grooves that run most of the length of the slabs.

``It's likely they were used to move materials - whatever was in the yard,'' Hatch said.

The first two trenches had the concrete slabs. Work recently started on the third trench, and it appears that a similar slab is also in that trench. Providing that no hazardous materials are found, the excavation project could be completed by October.

The 1.6-acre site was used as part of a chemical warfare material storage yard that was operated in the 1940s. Military records show that mustard gas, a chemical agent called lewisite and tear gas were sent to Edwards - then known as Muroc - during the years the yard was in operation.

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.

Debris from the trenches is being hauled to a disposal site inside the base's precision impact range area, a range used for weapons testing.

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.