N.J. Stat. § 40:33-13a
Any municipality which is a member of a county library system not exempted as provided hereafter, may withdraw from that system by resolution of the governing body adopted after a public hearing held thereon. Within 30 days of the adoption of such resolution, the municipal governing body shall provide the county governing body with notice of its intent to withdraw from the county library system. Such notice shall not become effective until January 1 of the year following the year in which the notice was given and shall provide that the municipality remain a member of the county library system for two years after the effective date of the notice.
Any municipality which withdraws from the county library system and which fails to comply with the provisions of this section shall be required to provide the county library with financial support in the manner provided in chapter 33 of Title 40 of the Revised Statutes for a period of two years from the year of the municipality's withdrawal from the system.
This section shall not apply to any county library system reorganized under the provisions of P.L. 1977, c. 300 (C. 40:33-15 et seq.) or P.L. 1963, c. 46 (C. 40:33-5.1 et seq.).
N.J.S. § 40:33-13a