Tainted Sand Disposal Halts Oil Field Cleanup

Cleanup at the Guadalupe oil field has been halted for as long as 2 1/2 years while Unocal Corp. and government officials try to find a new way to dispose of huge amounts of contaminated sand.

Unocal has discovered that its system of bioremediation, in which the contamination is allowed to naturally decompose to safe levels, is not working fast enough to allow the oil-tainted sand to be safely placed back into the ground.

The oil company has a pile of 360,000 cubic yards of contaminated sand dug up from various locations in the oil field that is still too polluted to be used as backfill.