D.C. Mayor Vince Gray said he's "leaning in the direction" of petitioning the Environmental Protection Agency to shut down an Alexandria power plant much despised by environmental groups.

The comment came after a report released Tuesday that concludes the District could keep its lights on if the Potomac River Generating Station were closed.

The report, written by an energy consultant and sponsored by the American Clean Skies Foundation, says new transmission and substation upgrades due to be completed in 2012 would make it possible for the Genon-owned plant to close without taking D.C.'s power with it.

The Sierra Club and other environmental groups have been pushing hard lately to put the plant on the fast track to closure, sponsoring a community meeting and paying for advertisements in the Farragut North Metro station that link the plant with asthma in the District.

The groups want Gray to file a special downwind complaint about the plant with the EPA, so that the federal agency could make new rules for the plant that would force it to clean up or shut down.

Gray's office said previously that he would need to make sure such a move would not hurt the District's power supply before filing with the EPA.

The new report says that Pepco and regional transmission operator PJM have made enough upgrades since 2005 to be able to provide power without the help of the Alexandria plant. In 2005 Virginia environmental officials came close to shutting the plant down, but were stopped by the U.S. Department of Energy, which was concerned D.C. and federal government buildings would lose power.

"There's plenty of other power plants in the area that could make up for the lost energy," said Paul Hibbard, a consultant for Analysis Group and the lead author of the report.

Genon has already promised to invest million in pollution controls for the plant and has reduced sulfur dioxide emissions by 80 percent since 2000, a Genon spokeswoman said Tuesday.

Gray said he has not yet made a final decision about the petition.