N.J. Stat. § 40:34A-6
Every municipality which shall make any contract, covenant or agreement with a county or pledge to a county pursuant to this act is hereby authorized and directed to do and perform any and all acts or things necessary, convenient or desirable to carry out and perform the same and to provide for the payment or discharge of any obligation thereunder in the same manner as other obligations of such municipality. Any such contract, covenant, agreement or pledge which may be made with or without consideration and for an unspecified or unlimited period of time and on any terms or conditions therein set forth shall be valid and binding on the parties thereto, and any instrument making or evidencing the same, may be pledged or assigned by the county to secure its bonds or notes and thereafter may not be modified except as provided by the terms of such instrument or by the terms of such pledge or assignment.
N.J.S. § 40:34A-6