N.J. Stat. Ann. § 40:33-9

Upon the adoption of the provisions of this article, the board of chosen freeholders shall determine a sum sufficient for the establishment and, annually thereafter, for the maintenance of the library. The sum so to be raised shall be certified by the board of chosen freeholders to the county board of taxation, which shall apportion such amount among the municipalities receiving the benefits of this article in accordance with the provisions of section 54:4-49 of the Revised Statutes. The sum so raised shall be not less than 1/15 of a mill per dollar on the "apportionment valuation," as defined in section 54:4-49 of the Revised Statutes, of the municipalities receiving the benefits of this article. The amount thus apportioned to each municipality shall be assessed, levied and collected in the same manner and at the same time as other county taxes are assessed, levied and collected therein.