N.J. Stat. Ann. § 18A:13-53

3. The county superintendent shall calculate the amount of indebtedness relating to buildings, grounds, furnishings, equipment and additions thereto so to be assumed on the basis of the proportion which the replacement cost of the buildings, grounds, furnishings, equipment, and additions thereto of the regional district situated in the withdrawing district, or in each of the constituent districts in the event of a dissolution, bears to the replacement cost of the buildings, grounds, furnishings, equipment and additions thereto situated in the entire regional district. Said replacement cost shall be determined according to rules prescribed by the commissioner with the approval of the State board and in accordance with recognized accounting practices. The county superintendent shall also calculate the amount of all other indebtedness and unfunded liabilities to be so assumed on an equitable basis.