“Air-gap separation” means a physical break between a supply pipe and a receiving vessel. The air gap shall be at least double the diameter of the supply pipe measured vertically above the top rim of the vessel, in no case less than one inch.

“Approved water supply” means any water supply approved by or under the public health supervision of a public health agency of the State of California, or its political subdivisions. In determining what constitutes an approved water supply, the State Department of Public Health reserves final judgment as to its safety and potability.

“Auxiliary supply” means any water supply on or available to the premises other than the public water supply.

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

“City” means the City of Sebastopol.

“Cross-connection,” as used in this chapter, means any unprotected actual or potential connection between a potable water system used to supply water for drinking purposes and any source or system containing unapproved water or a substance that is not or cannot be approved as safe, wholesome, and potable. Bypass arrangements, jumper connections, removable sections, swivel or changeover devices, or other devices through which back-flow could occur, shall be considered to be cross-connections.

“Double check valve assembly (DC)” means an assembly of at least two independently acting check valves including tightly closing shut-off valves on each side of the check valve assembly and test cocks available for testing the water tightness of each check valve.

“Health agency” means the California Department of Health Services, or the local health officer with respect to a small water system.

“Local health agency” means the County health authority.

“Reclaimed water” means a wastewater which as a result of treatment is suitable for uses other than potable use.

“Reduced pressure principal back-flow prevention device” means a device incorporating two or more check valves and an automatically operating differential relief valve located between the two checks, a tightly closing shut-off valve on each side of the check valve assembly, and equipped with necessary test cocks for testing.

“User connection” means the point of connection of a user’s piping to the water supplier’s facilities.

“Water supplier” means the person who owns or operates the public water supply system.

“Water user” means any person obtaining water from a public water supply system.