N.J. Stat. § 40:66A-27
After the creation of an incinerator or environmental services authority as provided herein, no municipality within the district shall have power to engage in, grant any license or permit for, or enter into any contract for, the collection, treatment and disposal of garbage and refuse; and no such municipality, or any person, firm, corporation or association shall engage in any activities within such municipality which would be competitive with the purposes of the incinerator or environmental services authority as provided in this act.
It is hereby determined and declared that it is necessary for the health and welfare of the inhabitants of every district within which an incinerator or environmental services authority is created that the facilities and services of such incinerator or environmental services authority shall be used by the owners or occupants of all lands, buildings and premises within such district, and the incinerator or environmental services authority may by resolution require the owners or occupants of all lands, buildings and premises therein to use the services and facilities of the incinerator or environmental services authority under such rules and regulations as the incinerator or environmental services authority shall fix and establish.
The provisions of this section shall not be construed, however, to affect or impair any contracts entered into prior to the creation of an incinerator or environmental services authority.
N.J.S. § 40:66A-27