Subject to the provisions of K.S.A. 66-104 and 66-131, and amendments thereto, any city operating any waterworks, fuel, power or lighting plant or sewer system may extend its mains, transmission lines or pipelines within or without the city by construction or purchase, when applications have been made and agreements entered into by persons along the proposed extension that will produce a revenue in the judgment of the governing body, sufficient to pay interest on the cost of the extension, and the operating cost of the product or service furnished.
K.S.A. 12-821