U.S. Tentatively Approves Shell Spill Plan for New Arctic Drilling In an important step toward ultimate approval of new oil drilling off the North Slope of Alaska, the Interior Department on Friday tentatively approved Shell's plans for responding to a potential spill in the frigid Arctic waters. Shell still needs to cross several additional regulatory barriers before it will be permitted to begin drilling as many as six exploratory wells in the Chukchi Sea starting in July. But the green light from the Interior Department on its oil spill response plan is a clear sign that the Obama administration is disposed to allow the drilling when it believes adequate safeguards are in place. "Alaska's energy resources - onshore and offshore, conventional and renewable - hold great promise and economic opportunity for the people of Alaska and across the nation," Ken Salazar, the interior secretary, said in a statement. In the Arctic frontier, cautious exploration - under the strongest oversight, safety requirements, and emergency response plans ever established - can help us expand our understanding of the area and its resources, and support our goal of continuing to increase safe and responsible domestic oil and gas production. "We are taking a cautious approach, one that will help inform the wise decisions of tomorrow," Mr. Salazar said. Shell has spent more than $4 billion over five years in its quest to exploit the vast oil and natural gas resources believed to lie beneath the Beaufort and Chukchi Seas off the north coast of Alaska. It has faced opposition from environmental groups and Alaska Natives who worry that extensive petroleum activities will foul the pristine seas and harm wildlife, including bowhead whales, ice seals, polar bears and walruses. Those groups are likely to try to block any drilling in court if final federal approval is granted in the coming months. Shell has proposed drilling up to six wells in the Chukchi Sea during the next two summer ice-free seasons within the Burger Prospect, about 70 miles off the coast in approximately 140 feet of water. Shell welcomed the decision, describing it as a "major milestone" in its path to drilling off the Alaska shoreline. "We recognize that industry's license to operate in the offshore is predicated on being able to operate in a safe, environmentally sound manner," said Pete Slaiby, Shell's top executive in Alaska. Shell's commitment to those basic principles is unwavering. Shell still must obtain permits from the Environmental Protection Agency for wastewater discharge and will need approval of specific well-drilling permits from the Department of Interior's Bureau of Safety and Environmental Enforcement. The company must also demonstrate that its well-capping technology can work in the harsh conditions of the Arctic and survive any court challenges to its drilling program. Opponents said that Shell and the Obama administration had not fully absorbed the lessons of the 2010 Deepwater Horizon blowout and oil spill in the Gulf of Mexico, which killed 11 rig workers and spilled millions of gallons of crude into the gulf. "They're just starting to look at issues we should have looked at three or four years ago," said Marilyn Heiman, director of the Arctic program at the Pew Environment Group. We need an additional two or three years of study to get the science right, to ensure proper monitoring and to protect wildlife. Ms. Heiman added, "They still don't have standards for the Arctic, which is very different from the temperate waters of the gulf - the ice, the wind, the darkness. We think there are major gaps in this plan and they need to take more time. Interior Department officials insisted that they had conducted an extensive scientific inquiry before moving ahead with the spill response plan. They also said that this work would continue before and after Shell is allowed out on the water and that officials would conduct several spill response drills before any drilling begins. They have also shortened the season that Shell will be allowed to operate offshore to ensure that it has shut down operations and has time to take any remedial actions before ice forms in the Chukchi. "This decision has been based on our new standards and our commitment to ensure the highest standard of safety and environmental preparedness in the world and our commitment to bringing science to all our activities in the Arctic," said David J. Hayes, the deputy secretary of Interior and coordinator of Arctic offshore drilling policy. Shell's response plan is designed to ensure that in case of a blowout or spill, the well could be shut down and any oil discharged contained speedily. If necessary, and with approval, spilled oil could also be burned off. The company promises to have personnel and equipment near the rigs at all time specifically dedicated to spill control. Boats, skimmers, booms, helicopters and barges will be on hand or at most an hour away from drilling rigs in case of an emergency. The equipment will all be specifically designed for harsh Arctic conditions, with reinforced hulls and materials designed for sub-freezing weather. One skimmer, the 300-foot Nanuq, will have a 12,000-barrel hold capacity. An additional tanker will have 513,000-barrel storage capacity. A rig would be available to come from nearby waters in case there was a need to drill a relief well designed to intercept and seal the original leaking well. The company says the blowout preventers it plans to use are designed to close a well within seconds. Learning from the BP disaster in the Gulf of Mexico, the blowout preventer design has been enhanced with an additional set of shear rams. Tests will be done on the equipment every seven days. In case the blowout preventer fails, Shell will keep a remotely operated vehicle, a submarinelike tool, on site to attempt to activate a paralyzed preventer underwater. Shell also promises to have an underwater capping system designed to quickly close in a leaking wellhead. A separate containment system would siphon oil from a leaking well. It will be designed to route the escaping oil to a floating processing facility. The company says in case of a spill, it will have aircraft on hand as well as prepared wind and current modeling charts to predict where flows might hit shore. John M. Broder reported from Milwaukee and Clifford Krauss from Houston. Correction: February 17, 2012 A previous version of this article misstated the amount of money that Shell has spent in its quest to exploit potential oil and gas resources off the north coast of Alaska. It is $4 billion, not $2 billion.