N.J. Stat. § 40:56-52
When a main sewer or drain, or a sewage disposal plant, or an outlet or connecting sewer, either within or without the municipality, or any improvement or addition to a sewerage system has been or shall hereafter be constructed in a municipality, and the benefits thereof shall be extended to real estate in the municipality by the subsequent construction of any lateral sewer or sewers, drain or drains, and the municipality has paid or is obligated to pay for such main sewer or drain, or sewage disposal plant, or outlet or connecting sewer, or any improvement or addition to the sewerage system or any part of the cost thereof, out of general funds, either because such work has been done at the general expense, or because the assessments therefor did not equal the total cost thereof, such real estate to which the benefits thereof shall have been extended, may be assessed therefor to an amount not exceeding the amount of the benefits actually received by such real estate notwithstanding that the municipality shall have paid such indebtedness or part thereof either in whole or in part. Such assessment may be made in connection with and as a part of the assessment for such lateral sewer or drain, or as an independent assessment, and shall be made and collected in accordance with the provisions of this chapter. Such assessment with interest thereon as collected from time to time shall be placed in the surplus revenue account of the municipality and controlled by the provisions of chapter 2 of this title (s. 40:2-1 et seq.).
N.J.S. § 40:56-52