What was CSAPR really driving?

The article discusses the implications of Cross State Air Pollution Rule (CSAPR) issued by the U.S. Environmental Protection Agency (EPA) after a DC District Court decision on August 21, 2012 that EPA erred in its implementation. EPA proposed a system where U.S. states would be required to clean up pollution in excess of significant contribution to downwind states' non-attainment. Throwing out CSAPR does not notably relieve EPA of their responsibility to address interstate pollution.