N.J. Stat. § 40:56-34
In all cases where any assessments for benefits incident to any improvement shall be set aside by a court of competent jurisdiction and the improvement shall have been actually made in the manner provided by law the officer or board charged with the duty of making assessments for benefits for local improvements, or in case of an assessment made by commissioners specially appointed then by such commissioners, shall make a new assessment of benefits upon the property benefited by the improvement, in the manner and by the proceeding herein provided. All such new assessments shall become a lien upon the property so assessed in the same manner and with like effect and be enforceable in the same way as an original assessment for like improvements.
When any court of competent jurisdiction shall decide that an assessment for a local improvement has been illegally made and no new assessment can be made the municipality shall refund the amount thereof, if the same has been paid, and if a new assessment of a less amount is made then the difference between the new assessment and the amount paid shall be refunded.
N.J.S. § 40:56-34