The Obama administration announced Monday that it is no longer fast-tracking offshore drilling projects in deep water by exempting them from detailed environmental review. Specifically, that means projects that use either a subsurface blowout preventer or a blowout preventer on a floating rig will need significantly more environmental review before drilling is allowed.

The exemptions, as ProPublica has noted, are exclusions to the National Environmental Policy Act, and they’ve long been used [1] to speed the permit process for oil companies and to lighten the paperwork for regulators. These exclusions were expansive [1], covering the entire central and western part of the Gulf of Mexico -- including BP’s plan to drill its “nightmare well” in the Gulf.

Since the Gulf spill, the Obama administration has been revisiting the way drilling projects like BP’s got fast-tracked under these exclusions, which were originally meant to avoid detailed environmental reviews for activities that were sure to have no significant environmental impact.

“In light of the increasing levels of complexity and risk -- and the consequent potential environmental impacts – associated with deepwater drilling, we are taking a fresh look at the NEPA process and the types of environmental reviews that should be required for offshore activity,” Interior Secretary Ken Salazar said in a statement [2].

We’ve reported on the use of categorical exclusions during the BP disaster [3] as well as the unanswered questions [1] about how the near-blanket use of exclusions in the western and central Gulf of Mexico came to be. The White House Council on Environmental Quality had earlier told us [1] that it no longer retains the documents about why the Gulf exclusions were created, but in a report released Monday [4], it said they were established in 1981 and 1986, “before deepwater drilling became widespread.”

The exclusions were established with the rationale that previous reviews had found that oil spills were unlikely to have significant environmental impacts. From the report:

The agency did not deem a catastrophic spill, comparable to the BP Oil spill, to be a reasonably foreseeable impact, based on historical information on spills in U.S. [Outer Continental Shelf] waters. Since April 20, 2010, that assumption will be revised, and [the Bureau of Ocean Energy] will take steps to incorporate catastrophic risk analysis going forward.

Regulators never conducted a site-specific review of BP’s Macondo well. The agency said in its report that “a site-specific review should also be undertaken in most cases,” and that the process for granting such exemption “was not transparent.” (Read the full report in our document viewer [4].)

The administration currently has placed a moratorium on deepwater drilling, but after the moratorium is lifted, regulators will require an environmental assessment [5].