Occupations: plumbers; requirements for backflow prevention testing; modify. Amends sec. 1107 of 2016 PA 407 (MCL 339.6107).

HB 5551 amends Michigan's plumbing regulations to require that anyone testing backflow preventers or air admittance valves must hold an active ASSE 5110 certification, as verified by the state department. This directly affects plumbers and technicians who perform backflow testing, mandating this specific certification for the task. The bill does not change general plumbing licensing requirements but adds a new certification standard for backflow testing to ensure qualified personnel. This is a concrete policy change focused on standardizing qualifications for a safety-critical aspect of plumbing work.