Legal Battles Begin on Trump Administration's Key Environmental Deregulatory Actions

Since taking office, President Donald Trump has launched an ambitious deregulatory effort targeting several federal environmental rulemakings completed during the Obama administration. Two of the most noteworthy deregulatory actions involve the scope of the federal government's authority to regulate greenhouse gas (GHG) emissions from existing sources under the Clean Air Act and discharges to surface water under the Clean Water Act. Lawsuits over these rules are pending or promised, with federal courts, and potentially the U.S. Supreme Court, poised to rule on whether the Trump administration's actions are appropriate course corrections or themselves illegal.

Clean Air Act

In 2015, the Obama administration promulgated the first-ever requirements for GHG emissions from power plants under the Clean Air Act. Known as the Clean Power Plan (CPP), this rule aimed to reduce GHG emissions from electricity generating units to approximately 32% less than 2005 levels by 2030. The CPP was challenged by numerous states and industry groups in the U.S. Court of Appeals for the District of Columbia Circuit. Challengers asserted that the Clean Air Act requirement to establish the "best system of emissions reduction" (BSER) prohibited the U.S. Environmental Protection Agency (EPA) from forcing fossil fuel plants to offset their emissions by constructing renewable energy sources or purchasing credits from such sources. In February 2016, the Supreme Court took the unprecedented step of staying the CPP before the D.C. Circuit ruled on the merits of the challenge. In September 2016, the entire D.C. Circuit heard oral arguments on the CPP, but effectively stayed the CPP lawsuit while the EPA moved forward with preparing a replacement.

On June 19, the EPA issued a final Affordable Clean Energy (ACE) rule establishing a much different set of requirements for BSER at existing power plants and formally repealing the CPP. Finalized after formal notice-and-comment rulemaking, the ACE rule adopts a series of thermal efficiency or heat rate improvements as BSER, but unlike the CPP, it does not set a formal limit on GHG emissions from existing coal-fired power plants. Effectively, the ACE rule requires coal-fired electricity generating units to reduce GHG emissions by employing operation and maintenance practices, using one of six listed "candidate technologies" each with its own pre-determined GHG emissions reductions, and evaluating other factors such as the source's remaining useful life. Under the ACE rule, states are required to submit plans to the EPA describing how each affected power generation unit within their jurisdiction meets the required "standards of performance."