In addition to the definitions found in § 490.2, the following definitions apply to this subpart—

Biodiesel means a diesel fuel substitute produced from nonpetroleum renewable resources that meets the registration requirements for fuels and fuel additives established by the Environmental Protection Agency under section 211 of the Clean Air Act; and

Qualifying volume means—

(1) 450 gallons; or

(2) If DOE determines by rule that the average annual alternative fuel use in light duty vehicles by fleets and covered persons exceeds 450 gallons or gallon equivalents, the amount of such average annual alternative fuel use.