(1) For negotiated and competitive sales the full amount may be paid before removal is begun under the contract or by installment at the discretion of the authorized officer. Installment payments must be based on the estimated removal rate specified in the operating plan and must be, as a minimum, the value of 1 month's removal. The first installment must be paid before removal operations are begun; remaining installments must be paid in advance of removal of the remaining materials as billed by the authorized officer. The total amount of the purchase price must be paid at least 60 days before the expiration date of the contract.

(2) All advance payment contracts must provide for reappraisal of the mineral material at the time of contract renewal or extension.

(3) Minimum annual production must be sufficient to return a payment to the United States equal to the first installment. In lieu of minimum production, there must be an annual payment in the amount of the first installment which will not be credited to future years' production. Payments for or in lieu of minimum annual production must be received by the authorized officer on or before the anniversary of the effective date of the contract.

(4) If the purchaser fails to make payments when due, the contract will be considered breached, the authorized officer will cancel the contract, and all previous payments will be forfeited without prejudice to any other rights and remedies of the United States.

(5) In order to determine payment amount, the purchaser must make a report of operations. The report must include the amount of mineral material removed, which must be verified by the authorized officer.

(1) The purchaser may make payments monthly or quarterly which must be based on the in-place value (volume or weight equivalent) of material removed during the contract period. The units of measurement must correspond to the units used in the appraisal. The purchaser must make all payments before contract renewal.

(2) The purchaser must deliver a bond which conforms to the provisions of § 228.51(a)(2) to the authorized officer before operations are begun under the contract.