70 ILCS 3705/10

Any public water district formed hereunder shall have the right to supply water to any municipality, political subdivision, private person or corporation located outside the limits of said district upon such payment, terms and conditions as may be mutually agreed upon, provided the water is delivered by such district to such party or parties at the corporate limits of such district or from such waterworks properties of such district located outside the district that have been constructed or acquired as necessary and incidental to the furnishing of water to the inhabitants of said district.