Following a federal court decision overturning the federal Clean Air Mercury Rule, on Jan. 30, 2009, the Commonwealth Court of Pennsylvania declared the Pennsylvania Mercury Rule unlawful, invalid and unenforceable and enjoined the Commonwealth from continued implementation/enforcement of the Rule. A copy of the Court's Opinion and Order can be downloaded.

The Pennsylvania Mercury Rule was published on Feb. 17, 2007, and regulated mercury emissions from coal-fired power plants. The rule required the plants to meet both annual allocations for mercury and comply with either an emission standard or a percent removal standard. The regulation followed the passage of the federal Clean Air Mercury Rule, which was vacated in New Jersey v. EPA, 517 F.3d 574 (D.C. Cir. 2008).

The Commonwealth Court found that the Pennsylvania Mercury rule violated the Pennsylvania Air Pollution Control Act in that the state is prohibited from establishing emission or performance standards for sources which are already listed as source categories under Section 112 of the Clean Air Act. As part of the rulemaking by EPA under the Clean Air Mercury Rule, EPA attempted to remove coal-fired power plants from the Section 112 list. The New Jersey court found that this removal attempt was illegal and vacated the rule removing power plants from the 112 list. The New Jersey's court ruling resulted in coal-fired power plants once again being on the 112 list, and since the Pennsylvania rule was valid only if the plants were not on the 112 list, the Commonwealth Court found the Pennsylvania Mercury Rule to be unlawful.

Reed Smith participated in the Pennsylvania case through the filing of an Amicus Brief on behalf of two utility clients.

On February 5, the state appealed the Commonwealth Court ruling to the Pennsylvania Supreme Court. The appeal operates as an automatic supersedeas of the Commonwealth Court's Order. We will provide updated information as this case progresses.