N.J. Stat. Ann. § 40A:31-17

The chief fiscal officer of another government having entered into a contract pursuant to this act, shall cause to be paid to the local unit such amounts of money at such times as shall be stipulated in the contract and certified by the local unit. The power and obligation to make payments in accordance with the terms of the contract shall be unlimited, and the sums necessary therefor shall be included in the annual budget of the other government, which shall be irrevocably and unconditionally obligated to levy ad valorem taxes on all taxable property therein, without limits as to rate or amount, to the extent necessary to make payments in full as due. Any part of a payment that remains unpaid for 30 days following the date payment is due, shall be assessed an interest charge at a rate of interest at least equal to the monthly index for the immediately preceding month for 20 year tax exempt bond yields as compiled by the Bond Buyer or any similar index agreed to by the parties.