The U.S. Environmental Protection Agency (EPA) last week sent its final so-called “Tailoring Rule” to the White House Office of Management and Budget (OMB) for review. The move signals that the rule, which could require power plants and other entities to obtain operating permits to emit greenhouse gases, is close to finalization.

Proposed in September 2009, the Tailoring Rule would phase in the application of the Clean Air Act’s Prevention of Significant Deterioration (PSD) and Title V permitting requirements to greenhouse gas (GHG) emissions from stationary sources. According to the EPA’s website, the final rule is expected to be published in the Federal Register this May.

EPA Administrator Lisa Jackson told Sen. John Rockefeller (D-W.Va.) and seven other senators from coal states earlier this year that only those facilities—fewer than 400—that already must apply for Clean Air Act permits as a result of their non-greenhouse gas emissions would need to address GHG emissions in their permit applications.

GHG emissions from other large sources would be phased in starting in the latter half of 2011. Jackson also said that between the latter half of 2011 and 2013, the threshold for permitting would be substantially higher than the 25,000-ton limit that the EPA originally proposed.

Sources: EPA, POWERnews