This April 2017 photo provided by the U.S. Environmental Protection Agency shows an oil well that was misting natural gas on Alaska's frozen North Slope. Workers from the Alaska Department of Conservation and the Environmental Protection Agency on Saturday, April 15, 2017, were able to connect hoses to valves that allow pressure in the well to be reduced, according to a statement from the state conservation department. The Environmental Protection Agency says a crack in the BP wellhead near Deadhorse sent up mist of crude oil Friday before it froze over and an initial leak stopped. (U.S. Environmental Protection Agency via AP)
This April 2017 photo provided by the U.S. Environmental Protection Agency shows an oil well that was misting natural gas on Alaska's frozen North Slope. Workers from the Alaska Department of Conservation and the Environmental Protection Agency on Saturday, April 15, 2017, were able to connect hoses to valves that allow pressure in the well to be reduced, according to a statement from the state conservation department. The Environmental Protection Agency says a crack in the BP wellhead near Deadhorse sent up mist of crude oil Friday before it froze over and an initial leak stopped. (U.S. Environmental Protection Agency via AP)
U.S. Environmental Protection Agency administrator Gina McCarthy makes remarks during a news conference Wednesday, May 21, 2014, in Salt Lake City. The head of the EPA was in Salt Lake City Tuesday to talk about the agency's efforts to reduce carbon pollution. The Utah appearance by EPA administrator McCarthy is her first stop in a three-city tour that also includes Seattle and Portland. She is meeting with politicians, local leaders and business people as the EPA tries to implement President Barack Obama's climate-change plan. (AP Photo/Rick Bowmer)
U.S. Environmental Protection Agency administrator Gina McCarthy makes remarks during a news conference Wednesday, May 21, 2014, in Salt Lake City. The head of the EPA was in Salt Lake City Tuesday to talk about the agency's efforts to reduce carbon pollution. The Utah appearance by EPA administrator McCarthy is her first stop in a three-city tour that also includes Seattle and Portland. She is meeting with politicians, local leaders and business people as the EPA tries to implement President Barack Obama's climate-change plan. (AP Photo/Rick Bowmer)
U.S. Environmental Protection Agency administrator Gina McCarthy makes remarks during a news conference Wednesday, May 21, 2014, in Salt Lake City. The head of the EPA was in Salt Lake City Tuesday to talk about the agency's efforts to reduce carbon pollution. The Utah appearance by EPA administrator McCarthy is her first stop in a three-city tour that also includes Seattle and Portland. She is meeting with politicians, local leaders and business people as the EPA tries to implement President Barack Obama's climate-change plan. (AP Photo/Rick Bowmer)
U.S. Environmental Protection Agency administrator Gina McCarthy makes remarks during a news conference Wednesday, May 21, 2014, in Salt Lake City. The head of the EPA was in Salt Lake City Tuesday to talk about the agency's efforts to reduce carbon pollution. The Utah appearance by EPA administrator McCarthy is her first stop in a three-city tour that also includes Seattle and Portland. She is meeting with politicians, local leaders and business people as the EPA tries to implement President Barack Obama's climate-change plan. (AP Photo/Rick Bowmer)
** FILE ** U.S. Environmental Protection Agency administrator Gina McCarthy makes remarks during a news conference Wednesday, May 21, 2014, in Salt Lake City. (AP Photo/Rick Bowmer)