For the purposes of this subchapter, unless the context requires otherwise, the following definitions, in addition to those in 75-6-102, MCA, apply:
(1) "Approved backflow prevention assembly or device" means an assembly or device approved by the department.
(2) "Back pressure" means any increase of water pressure in the downstream piping system above the supply pressure at a point where backflow could occur.
(3) "Back siphonage" means a form of backflow caused by a reduction in supply pressure which causes a negative or sub-atmospheric pressure to exist in the water system.
(4) "Backflow" means the undesirable reversal of water flow or the reversal of water flow containing other liquids, gases or other substances from a connected source that flows into the distribution pipes of the public water supply system.
(5) "Backflow prevention assembly" means an apparatus that consists of a backflow prevention device, two shutoff valves, and appropriate test ports.
(6) "Backflow prevention device" means an apparatus designed to prevent backflow.
(7) "Certified backflow prevention assembly tester" means a person who holds a current certificate issued by a certification program of any state authorizing the person to test backflow prevention assemblies or who holds a current certificate from the American Society of Sanitary Engineers or the American Backflow Prevention Association.
(8) "Cross-connection" is defined in 75-6-102, MCA.
(9) "Degree of hazard" means the level of risk created by either a pollutant (non-health hazard) or a contaminant (health hazard), as derived from an assessment of the materials that may come in contact with the distribution system through a cross-connection.
(10) "Health hazard" means a condition that causes or creates a potential for water contamination that may cause disease or have other physical or toxic effects on humans.
(11) "Non-health hazard" means a condition that causes or creates a potential for water quality degradation but does not constitute a health hazard.