At 9:30 a.m. on a warm day in March, eight men and two women stepped off Pennsylvania Avenue and into the northwest gate of the White House. They were top-level refining executives from the world's largest oil companies escorted by Jack Gerard, the brash president of the American Petroleum Institute, the oil industry's top lobby. Ushered into the West Wing, they met Valerie Jarrett, a longtime confidante of President Obama and White House power player. In the weeks before the meeting, EPA was advancing toward the White House new restrictions on the amount of sulfur in gasoline. But since that meeting with Jarrett, best known as Obama's "first friend," the sulfur rules have stalled in bureaucratic limbo while environmentalists have stewed.

For more than two years, the Environmental Defense Fund has been seeking to line up state regulators and energy companies behind a model regulatory framework for shale gas and oil development that protects underground drinking water supplies and public health. But EDF's search for regulatory consensus has pulled it into scarred political terrain, where some environmental groups oppose hydraulic fracturing outright and many industry and state officials challenge any moves to standardize regulation and oversight of a game-changing energy frontier.