All sewer charges shall become due and payable at the office of the city finance department on the date of presentation thereof and shall become delinquent on the thirtieth day after the date of presentation, except that closing bills, where service is discontinued, will be due and payable on date of presentation and collection will be made at the time of presentation. Fines are due as stipulated by the director of water resources and conservation. (Ord. 2282 NCS §3 (part), 2007.)