Air gap.A physical separation sufficient to prevent backflow between the free-flowing discharge end of the potable water system and any other system. It is physically defined as a distance equal to twice the diameter of the supply side pipe diameter, but never less than one (1) inch.
Approved.Accepted by the public works director as meeting an applicable specification stated or cited in this division or as suitable for the proposed use.
Atmospheric vacuum breaker.A device which prevents backsiphonage by creating an atmospheric vent when there is either a negative pressure or subatmospheric pressure in a water system.
Auxiliary water supply.Any water supply on or available to the premises other than the city’s approved public potable water supply.
Backflow.The flow of water or other liquids, mixtures or substances under positive or reduced pressure in the distribution pipes of the potable water supply from any source other than its intended source.
Backflow preventer.A device or means designed to prevent backflow or backsiphonage. Most commonly categorized as air gap, reduced pressure principle device, double check valve assembly, pressure vacuum breaker, atmospheric vacuum breaker, hose bibb vacuum breaker, residential dual check, double check with intermediate atmospheric vent, and barometric loop.
Backpressure.A condition in which the owner’s system pressure is greater than the supplier’s system pressure.
Backsiphonage.The flow of water or other liquids, mixtures or substances into the distribution pipes of a potable water supply system from any source other than its intended source caused by the sudden reduction of pressure in the potable water supply system.
Barometric loop.A fabricated piping arrangement rising at least thirty-five (35) feet at its topmost point above the highest fixture it supplies. It is utilized in water supply systems to protect against backsiphonage.
Commission.The state commission on environmental quality.
Containment.A method of backflow prevention which requires a backflow prevention device at the water service entrance.
Contaminant.A substance that will impair the quality of the water to a degree that it creates a serious health hazard to the public leading to poisoning or the spread of disease.
Cross-connection.Any actual or potential connection between the public water supply and a source of contamination or pollution.
Double check valve assembly.An assembly of two (2) independently operating spring-loaded check valves with tightly closing shut-off valves on each side of the check valves, plus properly located test cocks for the testing of each check valve.
Fixture isolation.A method of backflow prevention in which a backflow preventer is located to correct a cross-connection at an in-plant location rather than at a water service entrance.
Hose bibb vacuum breaker.A device which is permanently attached to a hose bibb and which acts as an atmospheric vacuum breaker.
Owner.Any person who has legal title to, or a license to operate or inhabit, a property upon which a cross-connection inspection is to be made or upon which a cross-connection is present.
Permit.A document issued by the department which allows the use of a backflow preventer.
Person.Any individual, partnership, company, public or private corporation, political subdivision or agency of the state, or any department, agency or instrumentality of the United States, or any other legal entity.
Pollutant.A foreign substance that, if permitted to get into the public water system, will degrade its quality so as to constitute a moderate hazard, or impair the usefulness or quality of the water to a degree which does not create an actual hazard to the public health but which does adversely and unreasonably effect such water for domestic use.
Pressure vacuum breaker.A device containing one (1) or two (2) independently operated spring-loaded check valves and an independently operated spring-loaded air inlet valve located on the discharge side of the check or checks. The device includes tightly closing shut-off valves on each side of the check valves and properly located each side of the check valves [sic] and containing properly located test cocks for the testing of the check valves.
Reduced pressure principle backflow preventer.An assembly consisting of two (2) independently operating approved check valves with an automatically operating differential relief valve located between the two (2) check valves, tightly closing shut-off valves on each side of the check valves, plus properly located test cocks for the testing of the check valves and the relief valve.
Residential dual check.An assembly of two (2) spring-loaded, independently operating check valves without tightly closing shut-off valves and test cocks. It is generally employed immediately downstream of the water meter to act as a containment device.
Water service entrance.That point in the owner’s water system beyond the sanitary control of the city, generally considered to be the outlet end of the water meter and always before any unprotected branch.
(1996 Code, sec. 11.703(e))