As used in this chapter:

"Air-gap separation" means a physical separation between the free flowing discharge end of a potable water supply pipeline and open or non-pressure receiving vessel. An approved air gap shall be at least double the diameter of the supply pipe measured vertically above the overflow rim of the vessel, and in no case less than one inch.

"Approved backflow prevention assembly" means an assembly which is listed by the Foundation for Cross-Connection Control and Hydraulic Research, University of Southern California (FCCC & HR, USC) as an approved backflow prevention assembly.

"Approved water supply" means any water supply whose potability is regulated by a state or local health agency.

"Atmospheric vacuum breaker" (AVB) (also known as the ‘non-pressure type vacuum breaker’) means an assembly containing a float-check, a check seat and air inlet port. The flow of water into the body causes the float to close the air inlet port. When the flow of water stops, the float falls and forms a check valve against backsiphonage and at the same time opens the air inlet port to allow air to enter and satisfy the vacuum. A shutoff valve immediately upstream may be an integral part of the assembly. An atmospheric vacuum breaker is designed to protect against a health hazard, (i.e. contaminant), under backsiphonage condition only. No shutoff valve may be installed downstream of an AVB.

"Auxiliary supply" means any water supply on or available to the premises other than the approved water supply. These auxiliary supplies may be polluted or contaminated or may be objectionable and constitute an unacceptable water source over which the water purveyor does not have sanitary control.

"AWWA Standard" means an official standard developed and approved by the American Water Works Association (AWWA).

"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 system.

"Backpressure" means any increase of pressure in the downstream piping system (by pump, elevation of piping, or steam and/or air pressure) above the supply pressure at the point where backflow could occur.

"Backsiphonage" means a form of backflow due to a reduction in system pressure which causes a sub-atmospheric pressure to exist at a site in the water system.

"Certified backflow prevention assembly tester" means a person who holds a current certificate from any state

certification program authorizing the person to test backflow prevention assemblies or who holds a current certificate from the American Society of Sanitary Engineers, American Backflow Prevention Association, Foundation for Cross-connection Control and Hydraulic Research, or American Water Works Association.

"Contamination" means a degradation of the quality of the potable water by any foreign substance which creates a hazard to the public health, or which may impair the usefulness or quality of the water.

"Critical level" means the C-L or C/L marking of the backflow prevention assembly which is the point established by the resting laboratory and marked by the manufacturer, from which the minimum required elevation above the flood run of a fixture, receptacle or other use is determined. In the absence of such marking, the lowest part of the assembly shall be deemed to be the critical level.

"Cross-connection" means any actual or potential connection between a potable water system used to supply water for drinking purposes and any other water supply system, either public or private, or a wastewater or sewer line or other potential source of contamination so that a flow of water into or contamination of the public water supply system is possible. By-pass arrangements, jumper connections, removable sections, swivel or changeover assemblies, or other assemblies through which backflow could occur shall be considered to be cross-connections.

"Degree of hazard" means either a pollution (non-health) or contamination (health) hazard and is derived from the evaluation of conditions within a system.

"Double check valve assembly" means an assembly of two internally loaded, independently acting check valves, including resilient seated shut-off valves on each end of the assembly and test cocks for testing the watertightness of each check valve.

"Double check-detector assembly" means a specially designed assembly composed of a line-size approved double check valve assembly with a specific bypass water meter and a meter-sized approved double check valve assembly. The meter shall register accurately for only very low rates of flow and shall show a registration for all rates of flow.

"Fixed air gap" means a backflow prevention assembly manufactured to meet the requirements of an air gap.

"Health agency" means the Montana Department of Environmental Quality (DEQ) or the Flathead County Health Department (FCHD).

"City of Columbia Falls water department" means any public water supply owned or operated by the city of Columbia Falls, a municipality.

"Non-potable water" means water which is not derived from a water supply and system under the authority of the appropriate health authority and is not approved for drinking, personal, or culinary use. Water in a fire, irrigation, reclaimed wastewater or industrial water system is deemed non-potable.

"Pollution" means an impairment of the quality of the water to a degree which does not create a hazard to the public health but which does adversely and unreasonably affect the aesthetic qualities of such waters for domestic use.

"Person" means an individual, corporation, company, association, partnership, municipality, public utility, or other public body or institution.

"Premises" means any and all areas on a water user’s property which are served or have the potential to be served by the public water system.

"Pressure vacuum breaker" means an assembly that has an independently operating, loaded check valve and an independently operating loaded air inlet valve located on the discharge side of the check valve. The pressure vacuum breaker must be equipped with the properly located test cocks and tightly closing shutoff valves located at each end of the assembly. This assembly is designed to protect only against a backsiphonage condition, not against backpressure. A shutoff valve may be used downstream of a pressure vacuum breaker.

"Public water supply" means a system for the provision of water for human consumption that has fifteen or more service connections or regularly serves at least twenty-five persons daily for a period of at least sixty days out of the year.

"Reduced pressure principle backflow prevention assembly" means an assembly incorporating two internally loaded, independently operating check valves and an automatically operating differential relief valve located between the two checks, including resilient seated shutoff valves on each end of the assembly and the necessary test cocks for testing the assembly.

"Reduced pressure zone detector assembly" means a specially designed assembly composed of a line-sized approved reduced pressure principle backflow prevention assembly with a specific bypass water meter and a meter-sized approved reduced pressure principle backflow prevention assembly. The meter shall register accurately for only very low rates of flow and shall show a registration for all rates of flow.

"Service connection" refers to the point of connection of a user’s piping the city of Columbia Falls water department system.

"Water supplier" means the person who owns or operates the approved water supply system.

"Water user" means any person obtaining water from an approved water supply. (Ord. 624 § 1(part), 2000)