On January 17, 2017, the U.S. Environmental Protection Agency (EPA) wrote to the American Petrochemical and Fuel Manufacturers (AFPM) denying its petition for partial supplemental waiver of the 2016 cellulosic biofuel standard under the Renewable Fuel Standard (RFS).  The letter was sent in response to AFPM’s December 28, 2016, petition for a supplemental waiver on the basis of an inadequate domestic supply of cellulosic biofuel, as reported in the blog post Petition for Waiver of 2016 Cellulosic Biofuel Volumetric Requirements.  In its response, EPA stated that the actual number of cellulosic biofuel Renewable Identification Numbers (RIN) or waiver credits that will need to be retired for compliance will not be known until the compliance deadline, since the compliance obligation is calculated on a percentage basis.  EPA anticipates that an additional 19 million 2016 cellulosic biofuel RINs will be generated in 2017, resulting in 197 million 2016 cellulosic RINs overall.  When combined with the 39 million carryover RINs from cellulosic biofuel produced in 2015, EPA estimates the total number of cellulosic biofuels RINs to be 236 million, which is greater than the 227 million RINs expected to be necessary for compliance.