The cost of last week’s rig accident, fire and eventual sinking in the Gulf of Mexico is continuing to rise. BP is responsible for the cleanup – a problem that, for now, at least, is continuing to grow. The UK oil company does not have insurance for oil spills, so will have to cover those costs itself. And it has yet to stem the leak.

Indeed, it became apparent today that it could take – in a worst case scenerio – several months to stop the leak. BP is attacking the problem on several fronts. The easiest and fastest is to activate the blow-out preventer, a system of valves designed to shut off an unexpected surge of oil or gas. If it can do that, the cleanup should be accomplished pretty quickly.

But, as a backup, BP already is bringing in two rigs to drill relief wells – a process that could take two to three months – to intersect the pipe and pump down a heavy fluid to stop the unrestrained flow. These rigs have to be taken away from work they were doing to drill other wells, which means a loss of time and money from those other operations. The process itself has its own costs, and it is time-consuming and delicate.