US expected to approve expanded biofuel waivers as early as Monday, sources say

The decision puts President Donald Trump in the middle of a longstanding fight between the oil refining and biofuel industries over the nation's Renewable Fuel Standard, which requires refiners to blend increasing amounts of ethanol and other renewable fuels into gasoline and diesel.

Farm-state lawmakers have warned that broad exemptions could depress demand for crops and undermine the biofuel industry, while refiners argue that the mandates can impose steep costs when compliance credits are expensive.

The Renewable Fuel Standard, established by Congress, requires refiners and fuel importers to blend specified volumes of renewable fuels into the nation's transportation fuel supply or purchase credits known as renewable identification numbers, or RINs.

Small refineries can seek exemptions from those requirements if complying would cause them disproportionate economic hardship. The EPA, which administers the program, has faced political pressure from both the refining and agricultural industries over how broadly to grant the waivers.