35 Pa. Stat. § 1680.206
All moneys of the agency from whatever source derived shall be paid to the treasurer of the agency and deposited in the first instance in one or more banks or trust companies, in one or more special accounts, each continuously secured by pledge of direct obligations of the United States of America or of the Commonwealth, or bonds of the agency, having an aggregate market value, exclusive of accrued interest, at all times, at least equal to the balance on deposit in the account. The security shall be either deposited with the treasurer or held by a trustee or agent satisfactory to the agency. All banks and trust companies are authorized to give the security required. The moneys of the agency shall be paid out on the warrant or other order of the treasurer of the agency or of another person authorized by the agency to execute warrants or orders. Notwithstanding the provisions of this section, the agency shall have power to contract with the holders of any of its bonds or notes as to the custody, security and payment of any moneys of the agency or any moneys held in trust or otherwise to secure the payment of bonds or notes. Deposits of moneys held in trust or otherwise to secure the payment of bonds or notes may be secured in the same manner as moneys of the agency and all banks and trust companies are authorized to give security for such deposits.
35 P.S. § 1680.206