U.S. Proposes Flooding to Clean Refuge

The U.S. Bureau of Reclamation on Thursday proposed a $1.1-million plan to clean up the selenium-contaminated Kesterson wildlife refuge by continually flooding the refuge reservoir with fresh water.

The proposal, the least expensive of a number of approaches outlined in a draft environmental impact statement made public Thursday, was greeted skeptically by environmentalists. However, bureau officials said at a news conference that they have prepared a “phased approach” that includes more elaborate and expensive alternatives if the flooding does not work.

Under the most costly plan, the bureau would have to spend an estimated $143 million to remove vegetation from the 5,900-acre refuge, dry the wetlands and haul away the selenium-contaminated sludge, regional director David G. Houston told reporters.

Kesterson, located near Los Banos, is the nesting place for millions of waterfowl along the Pacific flyway. In 1983, scientists began discovering deformities and deaths in the wildlife population. The problems eventually were traced to selenium that has accumulated in the refuge from agricultural drain water.

Minute Amounts

Selenium is an element naturally occurring in the soil. It is necessary for human and animal nutrition in minute quantities but can be toxic in larger amounts.

Fearful that selenium could contaminate underground aquifers serving nearby communities, the state Water Resources Control Board last February gave the Reclamation Bureau three years to clean up Kesterson. A month later, Interior Secretary Donald P. Hodel closed Kesterson, forcing the surrounding Westlands Water District to begin plugging agricultural drains that lead into the San Luis Drain, thus halting the flow of selenium-contaminated water.

The bureau hopes that by flooding 9,000 acre-feet of fresh, selenium-free water into the 1,285-acre reservoir on the Kesterson refuge, it can contain the selenium in mud layers on the reservoir bottom, “locking up” the toxic material so that it neither is taken up into the food chain by vegetation nor percolates into underground water supplies.

Houston told reporters this method is based on Lawrence Berkeley Laboratory studies currently under way that show the mud sediments at Kesterson appear to trap the selenium and offer a cheap and promising solution to cleanup problems. The fresh water would be pumped from underground sources or delivered from the Central Valley Project at bureau expense and would ultimately be repaid by water users.

However, environmentalists remain unconvinced. They say the flooding approach is based on preliminary results from Lawrence Laboratory studies that will not be completed for a year or more.

“There are some critical questions that still have not been answered,” said Tom Graff, a spokesman for the Environmental Defense Fund. Natural Resources Defense Fund lawyer Hamilton Candee suggested that the flooding plan would do little to prevent selenium that already is present at the site from contaminating new vegetation or underground water supplies.

Houston acknowledged that the Lawrence lab studies were far from complete.

“That’s why we’ve taken a phased approach to cleaning up Kesterson,” he said. “If this option doesn’t lock up the contamination, we will have to try the next expensive option.” The bureau will ask Congress for $27 million to cover cleanup costs in case the more expensive options are necessary, he said.

If the simple flooding of the ponds does not keep the selenium from being taken up by plants, the next alternative is to haul the vegetation away or burn it on site at a cost of about $13 million. If these options fail, then a $51-million “soil cap” could be layed down on the old reservoir bed or the mud could be scraped up and hauled away to a waste dump at a cost of $143 million.

The public has 60 days to comment on the draft environmental impact statement before it is put into final form. The bureau will hold public hearings in Los Banos, Fresno and Gustine on June 17-19. The final impact statement and cleanup plan will be presented to the Water Resources Control Board by Dec. 1, and the bureau has until Feb. 5, 1988, to complete the work.