N.J. Stat. Ann. § 40:14A-44

7. The cost of the installation of improvements for the purposes of section 3 of P.L.1999, c.11 (C.40:14A-40) shall be estimated by the sewerage authority engineer or by the applicant's engineer based on documented construction costs for public improvements prevailing in the general area of the sewerage authority. Any estimate prepared by the applicant's engineer shall be subject to approval by the sewerage authority engineer. The developer may appeal the sewerage authority engineer's estimate or decision to the county construction board of appeals established under section 9 of P.L.1975, c.217 (C.52:27D-127).