153.83 Free water and sewer services prohibited.—The same rates, fees and charges shall be fixed and collected from any county, school district or other political subdivision using the services and facilities of the water system or sewer system, or both, as are fixed and collected from other users of such facilities in the same class. No free water or sewer services shall be rendered by the district and no discrimination shall exist in the fees, rates and charges for users of the same class.