In what’s been called a “major blow” to Shell’s Arctic drilling plans, the Obama administration released a new permitting decision Tuesday which found that, due to wildlife protections, the company can’t simultaneously bore two wells into the Chukchi Sea. The oil company appears undeterred, saying it still intends to drill. The Department of Interior’s Fish and Wildlife Service sent what’s called a Letter of Authorization to Shell, saying the company’s two drilling rigs must maintain a buffer of at least 15 miles between them in order to minimize the number of Pacific walruses and polar bears that could be harmed by exploratory drilling activities. Right now, the rigs are proposed to operate simultaneously only nine miles apart. The new requirement aligns with existing regulations under the Marine Mammal Protection Act to protect marine species from harassment and displacement by industrial noise, but poses a significant restriction to Shell because the well sites identified in the company’s drilling plan lie well within 15 miles of each other. As a result, Shell must reassess its plan for simultaneous operations of its two contracted drilling rigs, since only one of its wells can be drilled at a time. Shell had planned for simultaneous well drilling this summer because such operations can only proceed before sea ice begins to form during the Arctic autumn. Tuesday’s action by FWS halves the rate at which Shell will be allowed to drill its exploratory wells this summer, should it secure its remaining outstanding federal permit for drilling operations from the Bureau of Safety and Environmental Enforcement. The decision from FWS comes shortly after lawyers with the public interest organization Earthjustice last week uncovered the regulatory discrepancy in Shell’s proposed exploration plan. In a letter delivered to the White House Tuesday morning that highlighted the finding, five Democratic Senators said Shell’s Arctic drilling proposal represented a “clear violation” of wildlife protection rules, one that “will negatively impact the resting, feeding, and breeding grounds of walruses.” Walrus, a species already affected by the impacts of climate change in the Arctic, are an important subsistence resource for Alaska Native coastal communities. In their letter, the Senators urged President Obama to “follow [his] own agencies’ guidelines to protect wildlife, indigenous peoples, and limit greenhouse gas emissions” and “to rescind Shell’s conditional Exploration Permit in the Chukchi Sea.” Drilling for oil in the Arctic is strongly opposed by environmentalists and some Alaska Native tribal groups who maintain that there is no proven safe method of drilling in the Arctic’s harsh climate, or of cleaning up an oil spill in an area with little to no infrastructure to support spill response. Asked during a twitter chat why his Administration is allowing Arctic drilling while trying to combat climate change, President Obama said the administration “can’t prevent oil exploration completely” in the Arctic, and is “setting the highest possible standards” for safety. The legal oversight highlighted in the Senators’ letter is the latest in a string of mistakes by Shell in its pursuit of Arctic oil. The company’s last attempt at exploratory drilling in the Arctic in 2012 included failures of key oil spill response equipment during testing and numerous felony safety and environmental law violations by a subcontractor resulting in more than $12 million in fines. Finally, when Shell sought to haul its massive Kulluk drilling vessel out of Alaskan waters in December that year to avoid state tax liability, the rig ran aground after severe weather caused it to snap its tow line. U.S. Coast Guard aviators evacuated Shell’s crew from the rig before it washed up on an uninhabited island. As of last weekend, Shell had already begun positioning its drilling vessels in Alaskan harbors in expectation of receiving its remaining federal permits. Elise Shulman is a communications associate for the Oceans Program at the Center for American Progress. Shiva Polefka, also of the Center, is a Policy Analyst for the Oceans Program. The post Obama Administration Deals Blow To Shell’s Arctic Drilling Plans appeared first on ThinkProgress.