(a) Except where the owner or operator has submitted a petition pursuant to § 66.13(a)(2), the first installment of the penalty shall be paid on the date six months after receipt of the notice of noncompliance.

(b) Where the source owner has filed a petition pursuant to § 66.13(a)(2), the first installment consisting of payment of penalties for all quarters “missed” as well as for the upcoming quarter shall be paid on the date six months after a final administrative decision affirming the source owner or operator's liability. Installments shall be paid quarterly thereafter until compliance is achieved. Quarters shall be measured in increments of three calendar months from the date the first payment is due.

(c) A source owner or operator who submits a petition pursuant to § 66.52 shall pay the penalty amount calculated by the owner or operator under § 66.13 or § 66.43 or any penalty calculated by EPA where the owner or operator has failed to calculate such penalty. Within 45 days after EPA has notified the owner or operator of a final administrative action after hearings on such petition, the owner or operator shall submit any necessary modification to the penalty. The revised penalty will be calculated in accordance with the Technical Support Document and the Manual, and a revised schedule, including appropriate adjustments for overpayments or underpayments made, will be established.

Payments in excess of $10,000 under this part shall be made by wire transfer payable to the U.S. Treasury. Payments under this part which are less than $10,000 shall be made by cashier's or certified check made payable to the United States Treasury, sent by registered mail, return receipt requested, and addressed to the Administrator, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460. Payment by check is made on the due date if it is postmarked on or before the due date. Payment by wire transfer is made on the due date if the Treasury's account is credited on or before the due date.

(a) Any source owner or operator who fails to make timely payment under § 66.61 shall pay in addition to the penalty owed a quarterly nonpayment penalty. The nonpayment penalty shall be calculated as of the due date of the noncompliance penalty payment and shall be equal to 20 percent of the aggregate amount of the noncompliance penalties and nonpayment penalties due and owing from the owner or operator on the due date. Partial payments shall be credited first against the nonpayment penalty, then against the noncompliance penalty.

(b) The Administrator shall notify the source owner or operator in writing of the amount of any nonpayment penalty for which the owner or operator is liable. Failure of the Administrator to provide such notice immediately shall not affect the legal obligation of the source owner or operator to pay such penalty. Such nonpayment penalty, as well as the past due noncompliance penalty, shall be payable immediately.