(a) The bonds may be additionally secured by:
(1) an encumbrance on any real property relating to a facility described by Section 1508.152(a) owned or to be acquired by the municipality; or
(2) an encumbrance on any personal property appurtenant to that real property.
(b) The governing body of the municipality may authorize the execution of a trust indenture, mortgage, deed of trust, or other form of encumbrance as evidence of the debt.
(c) The municipality may also pledge to the payment of the bonds all or part of any grant, donation, revenue, or income received or to be received from the United States or any other public or private source.