Deeper Burial Ordered at Planned Radioactive Dump

American Ecology, an Agoura Hills waste-management company that is preparing to build a low-level radioactive-waste dump in the Mojave Desert, will have to bury the waste deeper than planned, according to a state Department of Health Services ruling announced Monday.

Although “shallow” burial of the waste, as practiced in other arid states, “is adequate to protect the public health and the environment,” the state decided on a deeper burial “to increase the margin of safety,” State Health Director Kenneth W. Kizer said in a statement.

“Deeper burial provides extra protection against invasion of the waste by animals and deep-rooted plants, water and wind erosion, and the inadvertent intruder,” Kizer said.

But deeper burial will not increase the threat that the wastes will contaminate nearby ground water, because ground water is relatively deep and rainfall relatively low in that area of the desert, the agency said.

$30-Million Plant

U.S. Ecology, a unit of American Ecology, has been designated by the department to build and operate the $30-million plant west of Needles in the Ward Valley. U.S. Ecology has been working with the agency to draw up construction plans that will allow the company to receive a formal operating license.

U.S. Ecology hopes to open the plant in late 1991 or early 1992. The company doesn’t expect this change to add significantly to its costs for the project.

The deeper-burial rules mean waste buried at U.S. Ecology’s site will have to be at least 16 1/2 feet underground, the department said. U.S. Ecology also will have to provide separate trenches for class B and C wastes, which take up to 500 years to decay to harmless levels of radioactivity. Class A wastes take about 100 years to reach safe levels.

As originally planned, U.S. Ecology’s dump site would have been as shallow as 6 1/2 feet, and as deep as 16 1/2 feet.

Low-level radioactive wastes include clothing, tools, machinery, papers, cleaning wastes and filter materials that have been contaminated with radioactivity.

The Department of Health Services based its decision on a study conducted by Envirosphere Co., a consulting firm whose services were paid for by American Ecology, said Nicki Hobson, company spokeswoman. She said the state routinely asks consulting firms to evaluate waste-site proposals made by designated site operators such as American Ecology.