Sewer service charges shall be billed monthly, and are due upon receipt and such funds when collected, shall be placed in a separate fund known as the sewer maintenance fund or other appropriate title. Payment of the cost of sewage collection, treatment, maintenance of sewage facilities, repairs and administrative costs related thereto shall be made from said fund; capital expenses may also be paid from said fund. (Ord. 3-1991 § 4(d), 1991.)