A. Single-family residence, including mobile homes which upon the date of the ordinance codified in this section are served by individual water meters and the occupants or owners of which are billed directly: one ERU per month. Each mobile home located in a mobile home park where service is through a master water meter or if served by individual water meters, where the sewer service charges are, upon the date of the ordinance codified in this section, being billed to and paid by the owners of the mobile home park, shall, commencing April 1, 1989, and until January 1, 1990, be considered equivalent to 6/10 of an ERU; from January 1, 1990, until January 1, 1991, equivalent to 8/10 of an ERU; and commencing January 1, 1991, and thereafter, equivalent to one ERU per month;

B. Duplex (two-family) residence: two ERUs per month;

C. Triplexes, apartments and other multiple-family residential customers: 7/10 ERU per living unit;

D. Commercial or industrial customers not readily identified as a residential customer including, but not limited to, hotels, motels, boarding or rooming houses, nursing homes and transient (overnight) trailer parks: one ERU for each 900 cubic feet of water consumed with a minimum monthly charge of one ERU. (Ord. 923 §3, 1991; Ord. 854 §5, 1989; Ord. 166 §10(A), 1970).