N.J. Admin. Code § 15:22-1.12
Any member may withdraw from the library cooperative when its board of governance or the appropriate administrative authority determines by resolution or other recorded act to withdraw. Notification of intent to withdraw shall be submitted by the board of governance or the appropriate administrative authority to the executive board of the library cooperative, with a copy to the State Librarian. The notice shall be filed on or before April 1 of any year, and withdrawal shall take place on or before June 30 of the ensuing year. Upon discontinuing membership, the member relinquishes its rights to any funds, supplies, materials, equipment, or property held by or belonging to the library cooperative. Upon receipt of such notification and the satisfaction of all obligations by the withdrawing member, the executive board of the library cooperative shall officially note the withdrawal and shall file notice of this action with the State Library.
N.J. Admin. Code § 15:22-1.12