(a) Revenue bonds issued under § 1061.204 must be payable from and secured by liens on and pledges of all or any part of the revenue and income, other than ad valorem taxes, derived by the district from the operation of district facilities, the ownership of district facilities, or both. The board may pledge to the payment of revenue bonds all or any part of a grant, donation, or income received or to be received from the United States or any other public or private source under an agreement or otherwise.
(b) The bonds may be additionally secured by a mortgage or deed of trust on any real property on which a district hospital facility is or will be located and any real or personal property incident or appurtenant to the facility. The board may authorize the execution and delivery of a trust indenture, mortgage, deed of trust, or other form of encumbrance to evidence the security interest.