Section 154.403 - Periodic rate adjustments(a) This section applies to the passthrough, on a periodic basis, of a single cost item or revenue item for which passthrough is not regulated under another section of this subpart, and to revisions on a periodic basis of a gas reimbursement percentage.(b) Where a pipeline recovers fuel use and unaccounted-for natural gas in kind, the fuel reimbursement percentage must be stated in the tariff either on the tariff sheet stating the currently effective rate or on a separate tariff sheet or section in such a way that it is clear what amount of natural gas must be tendered in kind for each service rendered.(c) A natural gas company that passes through a cost or revenue item or adjusts its fuel reimbursement percentage under this section, must state within the general terms and conditions of its tariff, the methodology and timing of any adjustments. The following must be included in the general terms and conditions:(1) A statement of the nature of the revenue or costs to be flowed through to the customer;(2) A statement of the manner in which the cost or revenue will be collected or returned, whether through a surcharge, offset, or otherwise;(3) A statement of which customers are recipients of the revenue credit and which rate schedules are subject to the cost or fuel reimbursement percentage;(4) A statement of the frequency of the adjustment and the dates on which the adjustment will become effective;(5) A step-by-step description of the manner in which the amount to be flowed through is calculated and a step-by-step description of the flowthrough mechanism, including how the costs are classified and allocated. Where the adjustment modifies a rate established under subpart D of this part, the methodology must be consistent with the methodology used in the proceeding under subpart D of this part;(6) Where costs or revenue credits are accumulated over a past period for periodic recovery or return, the past period must be defined and the mechanism for the recovery or return must be detailed on a step-by-step basis. Where the natural gas company proposes to use a surcharge to clear an account in which the difference between costs or revenues, recovered through rates, and actual costs and revenues accumulate, a statement must be included detailing, on a step-by-step basis, the mechanism for calculating the entries to the account and for passing through the account balance.(7) Where carrying charges are computed, the calculations must be consistent with the methodology and reporting requirements set forth in § 154.501 using the carrying charge rate required by that section. A natural gas company must normalize all income tax timing differences which are the result of differences between the period in which expense or revenue enters into the determination of taxable income and the period in which the expense or revenue enters into the determination of pre-tax book income. Any balance upon which the natural gas company calculates carrying charges must be adjusted for any recorded deferred income taxes.(8) Where the natural gas company discounts the rate component calculated pursuant to this section, explain on a step-by-step basis how the natural gas company will adjust for rate discounts in its methodology to reflect changes in costs under this section.(9) If the costs passed through under a mechanism approved under this section are billed by an upstream natural gas company, explain how refunds received from upstream natural gas companies will be passed through to the natural gas company's customers, including the allocation and classification of such refunds;(10) A step-by-step explanation of the methodology used to reflect changes in the fuel reimbursement percentage, including the allocation and classification of the fuel use and unaccounted-for natural gas. Where the adjustment modifies a fuel reimbursement percentage established under subpart D of this part, the methodology must be consistent with the methodology used in the proceeding under subpart D of this part;(11) A statement of whether the difference between quantities actually used or lost and the quantities retained from the customers for fuel use and loss will be recovered or returned in a future surcharge. Include a step-by-step explanation of the methodology used to calculate such surcharge. Any period during which these differences accumulate must be defined.(d)Filing requirements.(1) Filings under this section must include: (i) A summary statement showing the rate component added to each rate schedule with workpapers showing all mathematical calculations.(ii) If the filing establishes a new fuel reimbursement percentage or surcharge, include computations for each fuel reimbursement or surcharge calculated, broken out by service, classification, area, zone, or other subcategory.(iii) Workpapers showing the allocation of costs or revenue credits by rate schedule and step-by-step computations supporting the allocation, segregated into reservation and usage amounts, where appropriate.(iv) Where the costs, revenues, rates, quantities, indices, load factors, percentages, or other numbers used in the calculations are publicly available, include references by source.(v) Where a rate or quantity underlying the costs or revenue credits is supported by publicly available data (such as another natural gas company's tariff or EBB), the source must be referenced to allow the Commission and interested parties to review the source. If the rate or quantity does not match the rate or quantity from the source referenced, provide step-by-step instructions to tie the rate in the referenced source to the rate in the filing.(vi) Where a number is derived from another number by applying a load factor, percentage, or other adjusting factor not referenced in paragraph (d)(1)(i) of this section, include workpapers and a narrative to explain the calculation of the adjusting factor.(2) If the natural gas company is adjusting its rates to reflect changes in transportation and compression costs paid to others:(i) The changes in transportation and compression costs must be based on the rate on file with the Commission. If the rate is not on file with the Commission or a discounted rate is paid, the rate reflected in the filing must be the rate the natural gas company is contractually obligated to pay;(ii) The filing must include appropriate credits for capacity released under § 284.243 of this chapter with workpapers showing the quantity released, the revenues received from the release, the time period of the release, and the natural gas pipeline on which the release took place; and,(iii) The filing must include a statement of the refunds received from each upstream natural gas company which are included in the rate adjustment. The statement must conform to the requirements set forth in § 154.501 .(3) If the natural gas company is reflecting changes in its fuel reimbursement percentage, the filing must include: (i) A summary statement of actual gas inflows and outflows for each month used to calculate the fuel reimbursement percentage or surcharge. For purposes of establishing the surcharge, the summary statement must be included for each month of the period over which the differences defined in paragraph (c) of this section accumulate.(ii) Where the fuel reimbursement percentage is calculated based on estimated activity over a future period, the period must be defined and the estimates used in the calculation must be justified. If any of the estimates are publicly available, include a reference to the source.(4) The natural gas company must not recover costs and is not obligated to return revenues which are applicable to the period pre-dating the effectiveness of the tariff language setting forth the periodic rate change mechanism, unless permitted or required to do so by the Commission.Order 582, 60 FR 52996, Oct. 11, 1995, as amended by Order 714, 73 FR 57535 , Oct. 3, 2008