72 Pa. Stat. § 308
In order to reimburse the General Fund for the costs incurred by the Treasury Department in making disbursements for departments, boards, or commissions out of special operating funds in the State Treasury, such departments, boards, or commissions, to which special operating funds are appropriated for this purpose, shall be billed at least quarterly by the Treasury Department, upon a cost basis, at such amount as the Treasury Department, with the approval of the Executive Board, shall determine. Amounts payable hereunder for reimbursing the General Fund for the cost of disbursement shall be paid out of such special operating funds to the Department of the Auditor General, and shall be by it paid into the General Fund of the State Treasury through the Department of Revenue.
72 P.S. § 308