More than four months after the Prestige oil tanker sank off the coast of Spain, a new plan is underway for permanently cleaning up what proved to be the worst environmental disaster in the nation’s history. About half of the ship’s load of 77,000 tons of fuel oil has already leaked out and devastated the local environment; now a Spanish company will attempt to extract and capture the remaining oil from the wreckage more than two miles beneath the surface of the Atlantic. In work expected to start this summer, the company will first attempt to affix a valve to the sunken ship and capture its oil in giant bags. If that fails, next it will try to construct a canopy over the wreck to stop oil that’s headed for the surface. As a last resort, it will try the tricky maneuver of pumping the oil out of the wreck. “Never before in history has an operation of this kind been performed,” said Spanish Deputy Prime Minister Mariano Rajoy. Meanwhile, neighboring France is working to ward off such a disaster in its own waters with tough new rules governing ship traffic within 90 miles of its Mediterranean coast.