President Joe Biden’s administration on Wednesday recommended a scaled-down version of a major oil drilling project in the North Slope of Alaska, taking a step toward approving the $8 billion Willow plan that climate groups have long condemned.

The Interior Department’s Bureau of Land Management released an environmental analysis that proposes lowering the number of drilling sites from five to three under the project, which is led by ConocoPhillips, Alaska’s largest crude oil producer.

The Biden administration has 30 days to issue a final decision on whether to approve the Willow project in the northernmost part of the state. The Interior emphasized it could select a different option, including taking no action or postponing a ruling about permits to more than one drill site.

The Willow project would produce about 600 million barrels of oil over 30 years and would generate around 278 million metric tons of carbon emissions, according to Interior estimates. Environmental advocates argue the plan would undermine the Biden administration’s agenda to curb fossil fuel production and say the project’s emissions would be roughly equivalent to what 66 new coal-fired power plants produce in a year.