11-4-4: EACH USER'S WASTEWATER SERVICE CHARGE:
   A.   Annual Wastewater Service Charge: Each nonresidential user's wastewater treatment cost contributions as determined by section 11-4-3 of this chapter shall be added together to determine such user's annual wastewater service charge.
   B.   Equitable Service Charge: Residential users may be considered to be one class of user and an equitable service charge may be determined for each user based upon an estimate of the total wastewater contribution of this class of user.
   C.   Classification Of Industrial And Commercial Establishments As Residential User: The governing body may classify industrial and commercial establishments as a residential user, provided that it is determined that such user will introduce primarily segregated domestic wastes or wastes from sanitary conveniences. (1975 Code § 13.24.040)