(1) An establishment must take appropriate corrective action, which may include shock disinfection, replacement, or repair of the water supply system within a period specified by the local health authority when:

(a) a water sample exceeds a maximum contaminant level as specified in ARM Title 17, chapter 38, subchapter 2;

(b) the supply does not have the capacity to provide enough water for drinking, cooking, personal hygiene, laundry, cleaning, and wastewater disposal;

(c) the local health authority reports to an establishment that the establishment's water supply system is vulnerable to contamination based on a site visit;

(d) a pathogenic microorganism is detected; or

(e) a confirmed disease outbreak is associated with the water supply through investigation.

(2) When a water supply is replaced or repaired, the water supply system must be shock disinfected before the system is placed into service.