All fire protection sprinkler system contractors, fitter certificate holders, or trainees, who install, alter, or repair, fire protection sprinkler systems or any part of such a system will comply with the provisions of this chapter.

(1) A person issued a certificate of competency by the Washington state department of labor and industries, under chapter 18.106 RCW, as a journey-level or residential specialty plumber or supervised plumber trainee installing a residential network fire protection sprinkler system connected to potable water who works for a contractor as defined by WAC 212-90-010(4) of this chapter.

(2) A person who inspects, field tests, maintains, or repairs backflow prevention assemblies installed on potable water supplies to fire sprinkler systems and who is certified as a:

(a) Backflow assembly tester by the Washington state department of health, under chapters 70A.120 RCW and 246-292 WAC; or

(b) Backflow specialty plumber by the Washington state department of labor and industries, under chapters 18.106 RCW and 296-400A WAC, when repairing backflow prevention assemblies within a building.