In the event that District does not elect, pursuant to Section 5.04.290, to collect current sewer service charges on the tax roll, the District shall bill for such charges. The regular billing period for sewer service charges shall be or each calendar month, bimonthly, or as determined by the Board. Schools and other public institutions may be required to pay semi-annually or annually. (Ord. 4 §4.1, 1973)