§ 42-52. Definitions.

The following words and terms used in this article shall have the following meanings:

Air gap. The unobstructed vertical distance through a free atmosphere between the lowest opening of a water outlet and the flood-level rim of any receptacle. This distance will be a minimum of two (2) times the diameter of the outlet, but never less than one (1) inch. In the case of near-walls, this distance will be three (3) times the diameter of the outlet.

Auxiliary supply. Any water source or system other than the public water supply that may be available in the building or premises.

Backflow. The reversal of flow from its intended direction as a result of backsiphonage or backpressure.

Backflow preventer. Any approved device, method, or type of construction intended to prevent backflow into a potable water system.

Backpressure. Backflow caused by a pump, elevated tank, boiler, air/steam pressure, or any other means capable of creating a pressure higher than the supply pressure.

Backsiphonage. Backflow caused by a negative or reduced pressure in the supply piping.

Contamination. The introduction into pure water of any undesirable substance (chemical, physical, radiological or biological) which may create a health hazard.

Cross connection. Any connection or structural arrangement, which has a direct or indirect effect on the waterworks system whereby backflow can occur, and includes any physical connection between a potable water supply and any waste pipe, soil pipe, sewer, drain or any unapproved source or system; also, any potable water supply outlet which is submerged or can be submerged in waste and/or other source of contamination.

Customer's service line. That portion of the customer's plumbing from the service connection to the first water outlet.

Degree of hazard. The level of health hazard, as derived from an evaluation of the potential risk to health and the adverse effect upon the waterworks system.

Double check valve assembly. A device composed of two (2) internally loaded, specially designed and independently operating check valves, situated between two (2) tightly closing, resilient-seated shutoff valves as an assembly, and equipped with properly located, resilient-seated test cocks.

Existing ground level. The level above which surface water will not accumulate under normal conditions.

Flood-level rim. The top edge of a receptacle over which water could overflow.

Hazard. Any condition, device or practice in the water usage system and its operation which creates, or reasonably tends to create, a danger to the health and well-being of the water consumer.

Office. The Commonwealth of Virginia, Department of Health, Office of Drinking Water.

Owner. The person having legal title to the property or the person in charge, care and control of the property where the facilities in question are located; also, the tenants of said property.

Pollution. The presence of any foreign substance (chemical, physical, radiological or biological) in water that tends to degrade its quality so as to constitute an unnecessary risk or impair the usefulness of the water.

Reduced pressure principal backflow preventer. A device consisting of two (2) independently acting, approved check valves together with a hydraulically operating, mechanically independent pressure differential relief valve located between the check valves and below the first check valve. These units are located between two (2) tightly closing resilient-seated shutoff valves as an assembly and are equipped with properly located resilient-seated test cocks.

Service connection. The terminal end of a water service from the waterworks system. If a meter is installed at the end of the water service, then the service connection means the downstream end of the meter.

Vacuum breaker, atmospheric. A vacuum breaker designed so as not to be subjected to continuous static line pressure, which prevents backsiphonage by creating an atmospheric vent when there is either a negative pressure or sub-atmospheric pressure in a water system.

Vacuum breaker, pressure. A vacuum breaker designed to operate under conditions of static line pressure, which prevents backsiphonage by creating an atmospheric vent when there is either a negative pressure or sub-atmospheric pressure in a water system. A pressure vacuum breaker contains 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 test cocks for testing of the check valve(s).

(Ord. No. 6233-06, § 1)

(Ord. No. 6233-06, § 1)