CSAPR Reinstated, But Some Upwind States May Be Able To Bring As-Applied Challenges

The U.S. Supreme Court today upheld the U.S. Environmental Protection Agency's Cross State Air Pollution Rule, otherwise known as CSAPR or the "Transport Rule," reversing a lower court decision that had vacated that rule.  The decision means that large sources of nitrogen oxide and sulfur dioxide emissions in upwind states – especially coal-fired power plants – will be subject to more stringent air pollution control requirements going forward.

Today's decision is an important victory for EPA and for the downwind states and other entities that supported the Transport Rule.  Indeed, the decision not only reinstates the Transport Rule, but also holds that EPA did not act prematurely in issuing federal implementation plans (FIPs) for that rule.