All fees and charges in connection with any customer's use of the City's sanitary sewer system, and the City's water facility system are billed in accordance with applicable rates set by the City Board of Trustees. All fees and charges owing for any of these utility services shall be billed on one monthly bill submitted to the customer each month. The utility bills submitted under the terms of this section shall be payable on or before the past due date which is printed on the bill. (1986 Code)