The agency on Wednesday backed off of two major air initiatives of the Bush Administration, citing a White House order against "midnight regulations" in the final 48 days of the presidency. The first was a change to NSR for power plants that would have calculated pollution using an hourly test rather than the current total measurement. The change met with complications after a court struck down the agency's Clean Air Interstate Rule (CAIR). The NSR changes would have worked in concert with CAIR requirements.

The second was an attempt to make it easier for coal-fired power plants, refineries and factories to be built near national parks. The rule change would have calculated releases over a one-year period, rather than the current 3-hour and 24-hour periods.

EPA spokesman Jonathan Shradar indicated recently that both changes were close to becoming law, but noted Wednesday that the agency essentially ran out of time to get it done.

Affected industries include electric services, petroleum refining, industrial chemical products, and pulp and paper mills.