Plugging the mudflow

Plugging the mudflow After struggling for nine months with hot torrents of mud, Indonesian officials are now experimenting with a new strategy to contain the noxious matter. In the last week of February, they dropped 300-400 kg concrete balls into the crater of the mud volcano. Over the next few weeks, they plan to drop nearly 1,500 balls into the crater. Critics, however, voice concern, as cutting the flow might just force the pent-up mud to seek some other outlets.

The mudflow disaster began on May 29, 2006, in a gas-drilling field in the village of Porong, near Sidoarjo, East Java. Spewing at a rate equivalent to about 1 million oil drums per day, the mudflow has so far covered 450 hectares of land, submerged four villages and displaced more than 13,000 people. The Indonesian government has been working to contain it with a network of embankments and by channelling some of it into the sea, but with little success.

The ball-dropping scheme to plug the crater was suggested by three geophysicists at the Bandung Institute of Technology, who believe the initiative could cut the flow by 75 per cent. With the help of a cable, stretched between a crane and a tower on either side of the volcano, four concrete balls are tied with 1.5 metre-long metal chain and then dropped into the crater. The team initially planned to drop five to 10 chains a day, but the process slowed down after the cable snapped on the very first day. Nylon-measuring lines attached to the first chain of balls indicate that the balls had gone down 700 metres, which means the conduit is much deeper than expected. It might take more than a month before the geologists notice any major change in the mudflow. As of now, they remain worried as little is known about the process. However, it might give the disaster team more time to channel the watery mud to a nearby river or come up with other solutions. Meanwhile, the affected villagers are protesting against the government and the oil company.