For the purpose of sections 13.12.030 through 13.12.070 of this chapter, the rate established by section 13.12.040 of this chapter for multiple-family buildings containing four (4) or more single-family residences without individual and separate water meters, such as apartment houses, condominiums, or other similar multiple dwelling units, shall be hereafter considered, for billing purposes, as commercial accounts. The monthly sewer service charge for commercial and industrial accounts shall be based upon the amount of water used by each such commercial or industrial business. The city will establish an average water use for each such business by averaging the monthly water consumption used by each such business from the months of October through March of each year after the beginning of such business. The average consumption from those months will then be projected for each month during the entire year. The monthly charge for commercial and industrial accounts shall be the average monthly consumption of water divided by eight thousand (8,000), which equals the number of residential equivalents, times the monthly fee per residence as set by resolution of the council. (Ord. 1381-85, 1985; amd. Ord. 2001-010, 2001)