66 Pa.C.S. § 1506: Copies of service contracts, etc., to be filed with commission.

Any public utility shall, when required by the commission, file with the commission verified copies of any and all contracts, writings, agreements, leases, arrangements, or other engagements, in relation to its public service, entered into by such public utility with any person, corporation, State Government, or the Federal Government, or any branch or subdivision thereof, or any other public utility.