U.S. firm mulls building geothermal power plant from Sidoarjo mudflow

They are probably just going for the whole heat exchange bit, since the mud flows on it's own you don't need to pump it, but question that begs asking is where is that mud gonna go after they're done with it?

Doesn't look like a very permanent solution to stick a power plant on top of it if said power plant just dumps the mud right back out.