Team to try to plug Lapindo?s mud flow with concrete balls

An Indonesian official hit back at critics of a plan to control a gushing mud flow by dropping concrete balls into its crater, saying something must be done to stop a nine-month-long eruption that has displaced 11,000 people.

A team of geologists and engineers hope the plan, believed to have never been tried before, will reduce the amount of mud flowing from the geyser at a gas exploration site on Java island by up to 70 percent.

Engineers will release five of the chained cement balls, each weighing up to 250 kilograms (550 pounds), and monitor the effect before gradually releasing more balls into the hole, Novrianto was quoted by AP as saying.

"Those experts can say what they want, but we have to do something," said Rudi Novrianto, a spokesman for a government task force handling the disaster. "There is no time to debate and sit around."

The team had planned to begin releasing the balls on Friday, but were forced to postpone the operation until a later date -- possibly as soon as Saturday -- due to technical problems, he said.

He said laboratory tests by geologists at Indonesia's most respected university had indicated the plan will work. (*)