N.J. Stat. Ann. § 40:62-105.28

The legal voters of any water district may vote to raise, either at a special meeting called by the water commissioners of said district or at the annual meeting of the voters of said district, a sum for waterworks and appurtenances thereto for water purposes, not exceeding five mills on the dollar of the last assessed valuation of the property in said water district. The sum so appropriated shall be assessed in the manner provided by law, and be expended by said commissioners for such water purposes as in their judgment they may deem expedient.