N.J. Stat. § 44:1-32

Upon the certificate of the state board that the housing conditions and accommodations are sufficient and adequate for the purpose, and the approval of the state board of health that the sanitary conditions are such as to properly safeguard the health of the poor persons to be maintained therein, the board of chosen freeholders of a county may contract with the board of chosen freeholders of another county to board and care for poor persons requiring permanent relief of such county, excepting municipalities thereof which elect not to participate in the county plan and which maintain their own permanent poor, and such contract authorized by the board and entered into by the directors of the counties concerned shall provide for the permanent maintenance and relief of such poor persons. A county so contracting may maintain its permanent poor in the almshouse or welfare-house in the other contracting county.