N.D. Cent. Code § 57-51-05.1
On all oil reclaimed from tank bottoms, pit oil, and saltwater, the gross production tax shall be paid by the operator of the reclaiming plant, unless taxes have already been paid thereon. If tank bottom or pit oil material is removed from the lease by the operator of a treatment plant, the gross value of oil reclaimed from the material is the purchase price paid by the operator of the treatment plant for the material from which the oil is reclaimed. If the operator has not paid a cash price for the material, the oil reclaimed has no value at the well. Every person, firm, association, corporation, or limited liability company engaged in the sale, purchasing, and refining of tank bottoms, pit oil, and saltwater shall report to the commissioner, upon forms prescribed by the commissioner, information necessary to the enforcement of this section.
N.D.C.C. § 57-51-05.1