For the purpose of the operation of the combined waterworks and sewage system the calendar year shall be divided into monthly periods, said periods to begin on the first day of each month of the calendar year. The rates or charges for service above provided shall be payable monthly on the first day of each month immediately following the end of the monthly period for which service has been supplied. The owner of the premises, the occupant thereof and the user of the service shall be jointly and severally liable to pay for the service on such premises and the services are furnished to the premises by the city only upon the condition that the owner of the premises, occupant and user of the service are jointly and severally liable to the city. All bills for service shall be rendered monthly on the first day of the month succeeding the monthly period for which the service is billed and shall be payable not later than the close of business on the tenth day of the same month. If payment of the full amount of the bill is not made within said period, then a penalty of ten percent (10%) of the amount of the bill shall be added thereto. Any check issued to the city of Spring Valley for payment of a water bill which is returned by the bank or other depository institution upon which the check is drawn for insufficient funds shall result in the customer having added to their bill a twenty five dollar ($25.00) charge for processing the insufficient funds check. (Ord. 1395, 10-27-2008)