Any special fuel User, Dealer or Supplier whether licensed or unlicensed, who maintains bulk storage of special fuel and who also owns (or controls) a licensed diesel motor vehicle or vehicles, is presumed to be fueling such vehicles from his own bulk storage facilities. If exception to this regulation is claimed by the User/Dealer/Supplier, he must be prepared to produce retail fuel purchase tickets to verify same. Recording of the vehicle odometer readings would also be advised to substantiate fuel used.
2 Del. Admin. Code § 2244-II-2.11