On April 25, 2022, a group of coal-fired power plant owners, a coal industry group, and coal-related labor unions filed a petition for review and application for preliminary injunction in the Commonwealth Court of Pennsylvania seeking to block regulations that went into effect April 23, 2022, the implementation of which would result in Pennsylvania’s participation in the Regional Greenhouse Gas Initiative (RGGI). Petitioners requested the court hold the rulemaking invalid and enjoin implementation and enforcement of the regulations. The respondents, the Pennsylvania Department of Environmental Protection (DEP) and the Environmental Quality Board, must file an answer by May 3, 2022.

Petitioners raise three main arguments in their brief supporting the application for preliminary injunction:

1. As we previously reported, petitioners allege the regulations impose a tax on the regulated entities without authorization by the state legislature, in violation of the Pennsylvania Constitution;
2. Petitioners allege the regulations are without statutory authority, as the state's Air Pollution Control Act (APCA) does not authorize the promulgation of regulations addressing CO2 emissions or a cap and trade program contemplated by RGGI; and
3. Petitioners argue that the rulemaking process contained procedural deficiencies in the process mandated by the APCA, as public hearings were held virtually instead of in-person hearings in regions affected by the regulations.

Meanwhile, a related lawsuit initially filed by the DEP to force the Legislative Reference Bureau to publish the regulation in the Pennsylvania Bulletin continues.  A status conference is scheduled for May 5, 2022 to discuss the impact of the April 23, 2022 publication of the RGGI regulations on a pending application for preliminary injunction filed by state Senators who intervened in the case. The application raises questions regarding the legitimacy of the RGGI regulations. Additionally, some electricity generation industry participants with hydroelectric and nuclear generating operations and environmental groups have sought to participate in defense of the regulations.

In recent years, the Commonwealth Court has shown a willingness to enjoin the enforcement of regulations pending a determination of their legality.