The Pennsylvania Supreme Court handed a victory this week to coal-fired electric generating facilities when it invalidated Pennsylvania's regulations limiting their emission of mercury. In its December 23, 2009 decision, the Court found that the Pa. regulations could not stand after the legal basis for the rule - a federal EPA decision which provided for state regulation of mercury emissions from oil and coal-fired electric generating units - was invalidated by the U.S. Court of Appeals for the D.C. Circuit.Background. In 2005, the U.S. Environmental Protection Agency (“EPA”) issued a final "Delisting Rule" which removed oil- and coal-fired electric generating units (EGUs) from the list of mercury pollution sources regulated under the hazardous air pollutants provisions of section 112 of the Clean Air Act. (70 Fed. Reg. 15994-01 (03/29/2005)). However, the EPA did not abolish regulation of mercury emissions from oil- and coal-fired EGUs. Rather, it shifted the responsibility for the mechanics of the regulation to the states. To accomplish this shifting to the states, the EPA promulgated the Clean Air Mercury Rule (“CAMR”). 70 Fed. Reg. 28606 (5/18/2005). CAMR was predicated on the Delisting Rule and it established a mercury emission budget for each state and required each state to develop a program to regulate the mercury emissions from oil- and coal-fired EGUs. Pennsylvania opted to develop a mercury regulation program that would keep emissions within the mercury budget set by the EPA and developed the PA Mercury Rule as the Pa. state response to CAMR. The PA Mercury Rule required, among other things, coal fired power plants to reduce their mercury emissions by 80% by January 2010.
EPA's decision to delist coal-fired electric generating stations from section 112's list of mercury sources was challenged in federal court. The D.C. Circuit Court of Appeals ultimately invalidated that delisting decision because EPA failed to follow the required delisting procedures. New Jersey v. Environmental Protection Agency, 517 F.3d 574 (D.C. Cir. 2008). The effect of that D.C. Circuit Court of Appeals decision was that EGUs remained listed as mercury sources under federal law, Section 112. The court also found that once the Delisting Rule was declared invalid, CAMR no longer had a legal basis and it vacated CAMR as well.
Because under the Pa. Air Pollution Control Act, DEP generally cannot regulate hazardous air pollutants which are federally regulated under Section 112 of the Clean Air Act, and the very basis for the Pa. Mercury Rule was EPA's delisting decision, the Pa. Supreme Court held that once the EPA delisting decision was invalidated by the D.C. Circuit Court of Appeals, the Pennsylvania state rule could not stand.
Case: PPL Generation, LLC, et al., v. Commonwealth of Pennsylvania, No, 7 MAP 2009 (Pa. Supreme Court, December 23, 2009