Tailoring Rule & Prevention of Significant Deterioration

In addition to the 'Endangerment Finding' announced by EPA today, the agency indicated it would soon finalize a new "Tailoring Rule" that will set a greenhouse-gas-emissions threshold for regulators at 25,000 tons a year. This is designed to target the largest emitters in the country. The EPA says that would mean around 13,600 coal-burning power stations, crude refineries, metal smelters and other industrial facilities would come under existing regulations. Specifically, for any new construction or modification that would affect greenhouse-gas emissions, companies would be required to apply for permits that include the "best available technology." The EPA is seen finalizing what is considered the best available technology in 2011.

The rule proposes new thresholds for greenhouse gas emissions (GHG) that define when Clean Air Act (CAA) permits under the New Source Review (NSR) and title V operating permits programs would be required for new or existing industrial facilities. The proposed thresholds would “tailor” the permit programs to limit which facilities would be required to obtain NSR and title V permits and would cover nearly 70 percent of the national GHG emissions that come from stationary sources, including those from the nation’s largest emitters—including power plants, refineries, and cement production facilities. Small farms, restaurants and many other types of small facilities would not be subject to these permitting programs.

Under the Prevention of Significant Deterioration (PSD) portion of NSR—which is a permit program designed to minimize emissions from new sources and existing sources making major modifications—EPA is proposing a:

1. Major stationary source threshold of 25,000 tpy CO2e. This threshold level would be used to determine if a new facility or a major modification at an existing facility would trigger PSD permitting requirements.

2. Significance level between 10,000 and 25,000 tpy CO2e. Existing major sources making modifications that result in an increase of emissions above the significance level would be required to obtain a PSD permit. EPA is requesting comment on a range of values in this proposal, with the intent of selecting a single value for the GHG significance level.

(EPA, WSJ, 12/7/09)