For the purpose of this subchapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
   AIR GAP SEPARATION.  The unobstructed vertical distance through the free atmosphere between the lowest opening from any pipe or faucet supplying pure water to a tank, plumbing fixture or other device and the rim of the receptacle.
   AUXILIARY WATER SYSTEM.  Any water system on or available to the premises other than the waterworks. These AUXILIARY WATERS may include water from another purveyor’s waterworks; or water from a source such as wells, lakes or streams; or process fluids; or used water. They may be polluted or contaminated or objectionable, or constitute a water source or system over which the water purveyor does not have control.
   BACKFLOW. The flow of contaminants, pollutants, process fluids, used water, untreated waters, chemicals, gases, non-potable waters into any part of a waterworks.
   BACKFLOW PREVENTION DEVICE.  Any approved device, method or type of construction intended to prevent backflow into a waterworks.
   CONSUMER.  The owner or person in control of any premises supplied by or in any manner connected to a waterworks.
   CONSUMER’S WATER SYSTEM.  Any water system located on the consumer’s premises, supplied by or in any manner connected to a waterworks.
   CONTAMINATION.  Any introduction into pure water of microorganisms, wastes, wastewater, undesirable chemicals or gases.
   CROSS-CONNECTION.  Any connection or structural arrangement, direct or indirect, to the waterworks whereby backflow can occur.
   DEGREE OF HAZARD.  This is a term derived from an evaluation of the potential risk to health and the adverse effect upon the waterworks.
   DOUBLE-GATE DOUBLE CHECK VALVE ASSEMBLY.  An approved assembly composed of two single, independently acting check valves including tightly closing shutoff valves located at each end of the assembly and petcocks and test gauges for testing the water tightness of each check valve.
   HEALTH HAZARD. Any condition, device or practice in a waterworks or its operation that creates, or may create, a danger to the health and well-being of the water consumer.
   INTERCHANGEABLE CONNECTION. An arrangement or device that will allow alternate but not simultaneous use of two sources of water.
   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.
   POLLUTION HAZARD.  A condition through which an aesthetically objectionable or degrading material may enter the waterworks or a consumer’s water system.
   PROCESS FLUIDS.  Any fluid or solution which may be chemically, biologically or otherwise contaminated or polluted which would constitute a health, pollutional or system hazard if introduced into the waterworks. This includes, but is not limited to:
      (1)   Polluted or contaminated waters;
      (2)   Process waters;
      (3)   Used waters originating from the waterworks which may have deteriorated in sanitary quality;
      (4)   Cooling waters;
      (5)   Contaminated natural waters taken from wells, lakes, streams or irrigation systems;
      (6)   Chemicals in solution or suspension; and
      (7)   Oils, gases, acids, alkalis and other liquid and gaseous fluids used in industrial or other processes, or for firefighting purposes.
   PURE WATER or POTABLE WATER.  Water fit for human consumption and use which is sanitary and normally free of minerals, organic substances and toxic agents in excess of reasonable amounts for domestic usage in the area served and normally adequate in supply for the minimum health requirement of the persons served.
   REDUCED PRESSURE PRINCIPLE BACKFLOW PREVENTION DEVICE.  A device containing a minimum of two independently acting check valves together with an automatically operated pressure differential relief valve located between the two check valves. During normal flow and at the cessation of normal flow, the pressure between these two checks shall be less than the supply pressure, in case of leakage of either check valve, the differential relief valve, by discharging to the atmosphere, shall operate to maintain the pressure between the check valves at less than the supply pressure. The unit must include tightly closing shut-off valves located at each end of the device, and each device shall be fitted with properly located test cocks. These devices must be of the approved type.
   SERVICE CONNECTION.  The terminal end of a service line from the waterworks, if a meter is installed at the end of the service, then the service connection means the downstream end of the meter.
   SYSTEM HAZARD.  A condition posing an actual, or threat of, damage to the physical properties of the waterworks or a consumer’s water system.
   USED WATER. Any water supplied by a water purveyor from waterworks to a consumer’s water system after it has passed through the service connection.
   WATER PURVEYOR. An individual, group of individuals, partnership, firm, association, institution, corporation, municipal corporation, county or authority which supplies water to any person within this state from or by means of any waterworks.
   WATERWORKS. All structures and appliances used in connection with the collection, storage, purification and treatment of water for drinking or domestic use and the distribution thereof to the public or residential consumers as set forth in VA Code § 62.1-45a.
(1996 Code, § 172-18)