The Environmental Protection Agency (EPA) wants to reconsider an air permit it awarded last July to the 1,500-MW coal-fired Desert Rock Energy Facility project proposed for construction by Sithe Global Power, LLC on the Navajo Nation tribal reservation in New Mexico.

The agency’s Region 9 on Monday filed a motion (PDF) with the Environmental Appeals Board (EAB) for a “complete remand” of the Final Prevention of Significant Deterioration (PSD) permit to more efficiently review sections appealed by the State of New Mexico.

These include reconsideration of the permit’s requirements for particulate matter of less than 2.5 micrometers (PM 2.5) and consideration of integrated gasification combined cycle (IGCC) as the best available control technology. The EPA will also review New Mexico’s assertion that the final permit decision was issued before Region 9 completed consultation under the Endangered Species Act, or before completing an analysis of Desert Rock’s emissions of hazardous air pollutants like mercury.

Region 9 had in early January—during the Bush administration—withdrawn a portion of its permitting decision regarding limitations on carbon dioxide to seek further comment on the issue. After the Obama administration took office, the agency had asked the EAB for an extension to more closely examine the issues. On Monday, the deadline for the EPA to file its final legal brief on the Desert Rock permit, Region 9 instead filed a motion for a voluntary remand.

“Given the number of the issues in the appeal that Region 9 seeks to reconsider and the prior withdrawal of a portion of the permitting record by Region 9, a complete remand of the Final PSD Permit and administrative record will promote efficiency in the Agency’s decision making and potentially enable Region 9 to resolve several disputed issues,” the motion said.

The remand means more delays for the $3 billion Desert Rock project. First proposed in 2004, it has been embroiled in legal battles and experienced several permitting roadblocks.

But the company intends to challenge the EPA’s decision to question the permit, according to the Durango Herald. The Desert Rock Energy Co. has notified the EPA that it could ask for documents related to the agency’s decision to reconsider the permit.

Sources: EPA, AG New Mexico, Durango Herald