N.J. Stat. § 43:15A-81
The Public Employees' Retirement System shall certify to each employer the rates of contributions payable by members who are county, municipal or school district employees. The system shall further certify, no later than December 31 each year, the contributions, including the accrued liability contribution similar to the State accrued liability contribution, payable by the county, municipality or school district to the contingent reserve fund on behalf of these members, and a pro rata share of the cost of the administration of the retirement system, based upon the payroll of the members who are employees of the county, municipality or school district. The initial actuarial expense incident to the determination of the accrued liability contribution, payable by the county, municipality or school district, shall be paid by the county, municipality or school district. The amount certified by the system as payable by the county, municipality or school district to the contingent reserve fund shall be included in the next budget subsequent to the certification by the system and levied and collected as any other taxes are levied and collected. The treasurer or corresponding officer of any county, municipality or school district shall pay to the State Treasurer no later than April 1 of the State's fiscal year in which payment is due the amount of the county, municipal or school district charges so certified. If payment of the full amount of such obligation is not made within 30 days after April 1, interest at the rate of 10% per annum shall commence to run against the unpaid balance thereof on the first day after such thirtieth day. The treasurer or corresponding officer shall also pay to the State Treasurer the amount of deductions from the compensation of the members who are employees of the county, municipality or school district. The State Treasurer shall credit these amounts to the appropriate fund or account.
N.J.S. § 43:15A-81