Notwithstanding litigation, Congressional probes, and simmering farm-state fury, the cascade of EPA “waivers” exempting so-called “small refineries” from Renewable Volume Obligation (RVO) compliance under the federal Renewable Fuel Standard (RFS) has accelerated.  EPA granted nearly 90% of 75 small refinery exemption petitions for compliance years 2017-18, with 21 petitions already pending for compliance year 2019.  Exempted volumes of gasoline and diesel fuel that otherwise would have been required to blend renewable biofuels or purchase covering RINs (Renewable Identification Numbers) soared from 2 billion gallons in 2013 (the first year “waivers” by individual petition were available) to 30 billion gallons in 2017-18, with  related RINs exemptions rising from 190 million to 3.2 billion RINs.

Food waste is composted by a wide range of technologies, from low-tech windrows that require only a front-end-loader to mix and turn piles, to medium-tech aerated static piles and windrow turning machines, to high-tech in-vessel containers with aeration and agitation systems. The guiding principle of higher tech equipment design is to maximize the presentation of surface area of the food waste to microbes within optimal oxygen and moisture concentrations, thus accelerating degradation.