Reasonable further progress
(t) Reasonable further progress (RFP) means both the emissions reductions required under CAA section 172(c)(2) which EPA interprets to be an average 3 percent per year emissions reductions of either VOC or NOX and CAA sections 182(c)(2)(B) and (c)(2)(C) and the 15 percent reductions over the first six years of the plan and the following three percent per year average under 51.1110.