For the purpose of this section, a "public utility" is defined to be a water, irrigation, sewer, gas, electric, telephone, bus, taxi, ambulance or railroad system or installation which serves five (5) or more customers whether or not to be franchised or organized as a corporation or district. Public utility installations shall be subject to the following requirements:

     A. Distribution, transmission and service lines for service to properties exclusively within Pueblo County requiring simple easements or installation in public rights-of-way or installed under franchise agreement with City and/or County and usual customer facilities for service to properties exclusively within Pueblo County shall not be subject to zoning requirements.

     B. Utility service facilities, the major use of which involves either office, mfg., warehousing, vehicle storage or maintenance functions, shall be constructed only in those zone districts in which a private firm not in the utility business would be permitted to establish a similar function or use.

     C. Special utility facilities, such as water reservoirs, sewage lagoons, switching yards, pumping stations, and other component equipment installations on land owned or leased and where the equipment is fenced or placed in a building shall not be constructed until Special Use Permit has been issued by the Planning Commission.

     D. These regulations shall in no way prohibit the installation of temporary facilities of the types described in subsections B and C of this section in cases of emergency conditions, provided within a reasonable period of time application is made for the installation of permanent facilities.