N.J. Stat. Ann. § 40:23-17

For the purpose of carrying into execution any such contract, any county, as a party thereto, may acquire real estate as tenants in common by purchase, gift or condemnation, erect buildings thereon and equip the same, acquire and hold any property in common, appoint such officers and employees as may be necessary for the joint enterprise and generally enter into any contract which the board of chosen freeholders or any municipality or district with which it may contract is authorized to enter into separately.