(a) Effectiveness of suspended rate schedules. If a rate suspension proceeding initiated under section 15(7) of the Interstate Commerce Act has not been concluded and an order has not been issued by the Commission at the expiration of the suspension period, the proposed rate, charge, classification, or service shall go into in effect so long as the pipeline company complies with all of the requirements of this section.

(b) Recordkeeping. Any pipeline company whose proposed rates or charges were suspended and have gone into effect pending final order of the Commission pursuant to section 15(7) of the Interstate Commerce Act shall keep accurate accounts in detail of all amounts received by reason of the rates or charges made effective as provided in the Commission's order, for each billing period, including the following information by billing period, and by shipper:

(1) The monthly billing determinants of petroleum or petroleum by-products transported to each consignee under the suspended tariffs;

(2) The revenues which would result from such transportation services if they were computed under the rates in effect immediately prior to the date the proposed change became effective, if applicable;

(3) The revenues resulting from such transportation services as computed under the proposed increased rates or charges that became effective after the suspension period; and

(4) The difference between the revenues computed in paragraphs (b)(2) and (3) of this section, if applicable.

(c) Refunds. (1) Any pipeline company that collects charges pursuant to this section shall refund at such time, in such amounts, and in such manner as may be required by final order of the Commission, the portion of any rates and charges found by the Commission in that proceeding not to be justified, together with interest as required in paragraph (c)(2) of this section.

(2) Interest shall be computed from the date of collection until the date refunds are made as follows:

(i) At an average prime rate for each calendar quarter on amounts held on or after February 11, 1983. The applicable average prime rate for each calendar quarter shall be the arithmetic mean, to the nearest one-hundredth of one percent, of the prime rate values published in the Federal Reserve Bulletin, or in the Federal Reserve's “Selected Interest Rates” (Statistical Release G. 13) for the most recent three months preceding the beginning of the calendar quarter; and

(ii) The interest required to be paid under paragraph (c)(2)(i) of this section shall be compounded quarterly.

(3) Any pipeline company required to make refunds pursuant to this section shall bear all costs of such refunding.

(4) If any rate or charge described in paragraph (a) of this section that is found not to be justified by the Commission is shared between two or more pipeline companies, each pipeline company which shared in the unjustified rates or charges is required to refund to the pipeline company that published the tariff, not less than five days prior to the refund date ordered by the Commission under paragraph (c)(1) of this section,

(i) That portion of the unjustified rates or charges shared, and

(ii) The appropriate interest as required in paragraph (c)(2) of this section for the period during which the refundable amounts were held.