The core of the lawsuit is a disagreement about the Clean Air Act, a bedrock environmental law in the US that lays out the EPA’s responsibility to protect the nation’s air quality by regulating pollution. Since 1970, EPA action under the Clean Air Act has led to a significant drop in major pollutants like particulate matter and nitrogen oxides.
Democrats have been trying to pass legislation that would push utilities to use more clean energy, but it’s been tied up in a congressional stalemate for months. [...] The court could limit a federal agency’s ability to expand its powers beyond anything explicitly written out in law by Congress.
Considering that the last congressional update on this law is from 1970, and with congress in perpetual deadlock for far longer than the mentioned months, I guess the plaintiffs are seeking to return to 50 year old environmental standards.
According to West Virginia, since standards of performance must be established “for any existing source,” they are case-specific, which makes it hard to interpret the term “best system” without taking a particular source into account. Since outside-the-fenceline measures do not connect to a specific source, West Virginia argues that they are excluded. West Virginia also emphasizes that any standard of performance must apply to the “stationary source,” which is the building itself, rather than to its “owner or operator,” [...]
The North American Coal Corporation (“NACC”), in support of West Virginia, argues that the D.C. Circuit’s interpretation of the case grants the EPA power to restructure all carbon-emitting industries with a huge level of control over economic activity across the country. The NACC goes further, contending that the EPA has been given “carte-blanche” to decide the entire climate change policy of the country.
I'd argue that it should be the EPA's job to regulate environmental protection across the entire country. Pollution doesn't stop at state borders. It also doesn't limit itself to specific industries. There's no point in creating individual rules for each and every powerplant - except perhaps making such regulation too much effort for the EPA's limited manpower.