The grandfathering provisions apply equally to facilities inside and outside the RFS program area. Facilities that commenced construction (as defined in §80.1403(a)(4)) prior to December 19, 2007, and which satisfy the timely construction requirements of §80.1403(c)(1) and (2) are included in the exemption specified in §80.1403(c).

For facilities which commenced construction between December 19, 2007 and December 31, 2009, the provisions of §80.1403(d) apply, which, in addition to specifying timely construction requirements also restrict the exemption to 1) only ethanol produced, and 2) only that produced from facilities which are fired exclusively with natural gas, biomass, or a combination of these fuels.