Neither the solid waste management authority nor any local unit shall have power to mortgage, pledge, encumber or otherwise dispose of any part of the garbage and solid wastes disposal system, except that the solid waste management authority may dispose of such part or parts thereof as may be not longer necessary for the purposes of the solid waste management authority. The provisions of this section shall be deemed to constitute a part of the contract with the holder of any bonds. All property of a solid waste management authority shall be exempt from levy and sale by virtue of an execution and no execution or other judicial process shall issue against the same nor shall any judgment against a solid waste management authority be a charge or lien upon its property; provided, that nothing herein contained shall apply to or limit the rights of the holder of any bonds to pursue any remedy for the enforcement of any pledge or lien given by a solid waste management authority on its system revenues.
N.J.S. § 40:66A-55