(a) The following acts, work, and conduct may be performed by anyone, without registration or certificate, provided, however, that all work and services herein named or referred to shall be subject to an inspection and approval in accordance with the terms of all state laws and applicable municipal ordinances:

(1) Plumbing work performed by anyone who is regularly employed or acting as a maintenance person incidental to and in connection with the business in which he or she is employed and engaged, provided the plumbing work is performed on the premises of the employer, and who does not engage in the occupation of a plumber for the general public.

(2) Plumbing work performed upon the premises or equipment of a railroad or other businesses or industry, by an employee thereof who does not engage in the occupation of a plumber for the general public.

(3) Plumbing or gas fitting work performed, not on private property, with the exception of easements, by persons engaged by or employed by any public utility company in the laying, maintenance, and operation of its service mains or lines and the installation, alteration, adjustment, repair, removal, and renovation of all types of appurtenances, and equipment provided such work does not alter gas piping on consumer side of meter.

(4) Any person engaged solely in the testing of backflow devices.

(5) Plumbing work performed by a property owner in or about a building owned or occupied by the owner.

(6) Any person may install washing machines to existing piping installation or waste lines, provided such plumbing work does not necessitate tying into waste or sewer lines on the outlet side of the trap.

(b) This chapter does not apply to any plumbing work performed by a property owner in or about a building owned or occupied by him or her, or plumbing work performed by anyone who is regularly employed by the property owner to provide maintenance or other repair services if the work is incidental to and in connection with the property for which he or she is employed and engaged and is done on the premises of the employer.