220 ILCS 5/5-104
2021 Illinois Compiled Statutes|Chapter 220 - UTILITIES|220 ILCS 5/ - Public Utilities Act.|Article V - Duties Of Public Utilities - Accounts And Reports

 (from Ch. 111 2/3, par. 5-104)Sec. 5-104. Depreciation accounts.(a) The Commission shall have power, after hearing, to require any or  all public utilities, except electric public utilities, to keep such  accounts as will adequately reflect  depreciation, obsolescence and the progress of the arts. The Commission  may, from time to time, ascertain and determine and by order fix the proper  and adequate rate of depreciation of the several classes of property for  each public utility; and each public utility shall  conform its depreciation  accounts to the rates so ascertained, determined and fixed.(b) The Commission shall have the power, after hearing, to require any or  all electric public utilities to keep such accounts as will adequately reflect  depreciation, obsolescence, and the progress of the arts.  The Commission may,  from time to time, ascertain and determine and by order fix the proper and  adequate rate of depreciation of the several classes of property for each  electric public utility; and each electric public utility shall thereafter,  absent further order of the Commission, conform its depreciation accounts to  the rates so ascertained, determined and fixed until at least the end of the  first full calendar year following the date of such determination.(c) An electric public utility may from time to time alter the  annual rates of depreciation, which for purposes of this  subsection (c) and subsection (d) shall include amortization,  that it applies to its several classes of assets so long as  the rates are consistent with generally accepted accounting  principles.  The electric public utility shall file a statement with  the Commission which shall set forth the new rates of  depreciation and which shall contain a certification by an  independent certified public accountant that the new rates of  depreciation are consistent with generally accepted accounting  principles.  Upon the filing of such statement, the new rates  of depreciation shall be deemed to be approved by the  Commission as the rates of depreciation to be applied  thereafter by the public utility as though an order had been  entered pursuant to subsection (b).(d) In any proceeding conducted pursuant to Section 9-201 or 9-202 to set  an electric  public utility's rates for service,  the Commission may determine not to use, in determining the  depreciation expense component of the public utility's rates  for service, the rates of depreciation established pursuant to  subsection (c), if the Commission in that proceeding finds  based on the record that different rates of depreciation are  required to adequately reflect depreciation, obsolescence and  the progress of the arts, and fixes by order and uses for  purposes of that proceeding new rates of depreciation to be  thereafter employed by the electric public utility until the end of the  first full calendar year following the date of the  determination and thereafter until altered in accordance with  subsection (b) or (c) of this Section.(e) A gas public utility serving more than 1,600,000 customers as of January 1, 2013 may from time to time alter the annual rates of depreciation, which for purposes of this subsection (e) shall include amortization, that the gas public utility applies to its several classes of assets so long as the rates are consistent with generally accepted accounting principles. The gas public utility shall file testimony with the Commission setting forth the new rates of depreciation that shall include: (i) a summary of the causes for the change in depreciation rates; (ii) a certification by an independent certified public accountant that the new rates of depreciation are consistent with generally accepted accounting principles; (iii) the depreciation study; and (iv) the expected impact on depreciation expense from the new depreciation rates.  The gas public utility shall also simultaneously submit to the Commission all work papers that support the filed depreciation study. No later than 120 days after the filing by the gas public utility under this subsection (e), the Commission shall ascertain and determine and, by order, fix the proper and adequate rate of depreciation of the several classes of property for the gas public utility. The gas public utility shall conform its depreciation accounts to the rates so ascertained, determined, and fixed. Rates of depreciation established by the Commission pursuant to this subsection (e) shall become effective upon the date of the gas public utility's filing. (Source: P.A. 98-473, eff. 8-16-13.)