N.J. Stat. Ann. § 40:37-13

In counties wherein the legal voters have heretofore adopted the provisions of an act entitled "A supplement to the act entitled "An act in relation to county expenditures,' approved April second, one thousand eight hundred and seventy-eight," approved March twenty-eighth, one thousand nine hundred and two, the board of chosen freeholders shall be governed by the provisions of sections 40:37-14 and 40:37-15 of this title.