This major group includes establishments engaged in the generation, transmission and/or distribution of electricity or gas or steam, water and irrigation systems, and sanitary systems engaged in the collection and disposal of garbage, sewage and other wastes by means of destroying or processing materials, are also included:

    491.  Electric services;

    492.  Gas production and distribution;

    495.  Sanitary services;

    497.  Irrigation systems. (Prior code § 11-20-050)