66 Pa.C.S. § 1702: Continuing property records.

The commission may require any public utility to establish, provide, and maintain as a part of its system of accounts, continuing property records, including a list or inventory of all the units of tangible property used or useful in the public service, showing the current location of such property units by definite reference to the specific land parcels upon which such units are located or stored. The commission may require any public utility to keep accounts and records in such manner as to show, currently, the original cost of such property when first devoted to the public service, and the reserve accumulated to provide for the depreciation thereof.