§ 51.151  DEFINITIONS.
   For the purpose of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
   AIR GAP (AG). A physical separation between the free-flowing discharge end of a water supply pipeline and an 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 in no case less than one inch (2.54 cm).
   APPROVED CHECK VALVE.
      (1)   A check valve that is drip-tight in the normal direction of flow when the inlet pressure is at least one psi and the outlet pressure is zero.
      (2)   The check valve shall permit no leakage in a direction to the normal flow. The closure element (e.g. clapper, poppet, or other design) shall be internally loaded to promote rapid and positive closure.
      (3)   An approved check valve is only one component of an approved backflow prevention assembly (i.e. pressure vacuum breaker, double-check valve assembly, double-check detector assembly, reduced pressure principle assembly, or reduced pressure principle detector assembly). These devices must have met the design performance standards of the American Society of Sanitary Engineers (ASSE), the American Water Works Association (AWWA), or the Foundation for Cross Connection Control and the Hydraulic Research of the University of Southern California and approved by the town.
   ATMOSPHERIC TYPE VACUUM BREAKER (AVB) or NON-PRESSURE TYPE VACUUM BREAKER. A device containing a float-check, a check seat, and an 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 valve against back-siphonage 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 device, an atmospheric vacuum breaker is designed to protect against a non-health hazard (isolation protection only) under a back-siphonage condition only.
   AUXILIARY WATER SUPPLY. Any water supply on or available to the premises other than the purveyor's approved public water supply shall be considered as an auxiliary water supply. These waters may be contaminated or polluted or they may be objectionable and constitute an unacceptable water source over which the water purveyor does not have sanitary control.
   BACKFLOW. An assembly used to prevent backflow into a consumer or public potable water system. The type of assembly used should be based on the degree of hazard either existing or potential (as defined herein). The types are:
      (1)   Double-Check valve assembly (DCVA);
      (2)   Double Check Detector Assembly (Fire System) (DCDA);
      (3)   Pressure Vacuum Breaker (PVB);
      (4)   Reduced Pressure Principle Assembly (RP); and
      (5)   Reduced Pressure Principle-Detector Assembly (Fire System) (RPDA).
   BACKPRESSURE. Any elevation 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 of consideration (delivery) which would cause or tend to cause, a reversal of the normal direction of flow.
   BACKSIPHONAGE. A reversal of the normal direction of flow in the pipeline due to a reduction in system pressure which causes sub-atmospheric pressure to exist at a site in the water system.
   CERTIFIED BACKFLOW PREVENTION ASSEMBLY TESTER or TESTER. A person who has proved their competency to the satisfaction of the town. Each person who is certified to make competent tests, or to repair, overhaul, and make reports on backflow prevention assemblies shall be knowledgeable of applicable laws, rules, and regulations, shall be a licensed plumber, or have at least two years experience under and be employed by a North Carolina licensed plumber or plumbing contractor, or have equivalent qualifications acceptable to the town, and must hold a valid "certificate of completion" from an approved training program in the testing and repair of backflow prevention assemblies recognized by the town.
   CONSUMER. Any person, firm, or corporation using or receiving water from the town.
   CONSUMER’S POTABLE WATER SYSTEM. That portion of the privately owned potable water system lying between the point of delivery and point of use and/or isolation protection. The system will include all pipes, conduits, tanks, receptacles, fixtures, equipment, and appurtenances used to produce, convey, store, or use potable water.
   CONSUMER’S WATER SYSTEM. Includes any water system commencing at the point of delivery and continuing throughout the consumer's plumbing system located on the consumer's premises, whether supplied by the public potable water or an auxiliary water supply. The system may be either a potable water system or an industrial piping system.
   CONTAINMENT. Preventing the impairment of the public potable water supply by installing an approved backflow prevention assembly at the service connection.
   CONTAMINATION. An impairment of the quality of the water which creates a potential or actual hazard to the public health through the introduction of hazardous or toxic substances or waterborne health hazards in the form of physical or chemical contaminants or biological organisms and pathogens.
   CROSS-CONNECTION. Any unprotected actual or potential connection, or structural arrangement between a public or a consumer's water system and any other source or system through which it is possible to introduce any contamination or pollution, other than the intended potable water with which the system is supplied. Bypass arrangements, jumper connections, removable sections, swivel or changeover devices, and other temporary or permanent devices through which or because of which "backflow" can or may occur are considered to be cross-connections.
   DEGREE OF HAZARD. Shall be derived from the evaluation of conditions within a system which can be classified as either a "pollutional" (non-health) or a "contamination" (health) hazard.
   DOUBLE-CHECK DETECTOR ASSEMBLY (DCVA). 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 (in U.S. gallons) accurately for very low rates of flow and shall show a registration for all rates of flow. This assembly shall only be used to protect against a non-health hazard (i.e., pollutant). Device must be approved by the Foundation for Cross-Connection Control and Hydraulic Research.
   DOUBLE-CHECK VALVE ASSEMBLY (DCVA). An assembly composed of two  independently acting, approved check valves, including tightly closing shut-off valves attached at each end of the assembly and fitted with properly located test cocks. The assembly shall only be used to protect against a non-health hazard (i.e. pollutant). Device must be approved by the Foundation for Cross-Connection Control and Hydraulic Research.
   HEALTH AGENCY. The North Carolina Department of Environmental and Natural Resources.
   HEALTH HAZARD. An actual or potential threat of contamination of a physical, chemical, biological, pathogenic or toxic nature to the public or consumer's potable water system to such a degree or intensity that there would be a danger to health. Examples of waterbome health hazards include but are limited to:
      (1)   Physical: radioisotopes/radionuclides;
      (2)   Chemical: lead, mercury, and other heavy metals, organic compounds, other toxins and hazardous substances; and
      (3)   Biological: microorganisms and pathogens like Cryptosporidium, typhoid, cholera and E. Coli.
   INDUSTRIAL FLUIDS. Any fluid or solution which may be chemically, biologically, or otherwise contaminated or polluted in a form or concentration such as would constitute a health, or non-health hazard if introduced into a public or consumer potable water system. Such fluids may include but are not limited to: process waters, chemicals in fluid form, acids and alkalis, oils, gases, etc.
   INDUSTRIAL PIPING SYSTEM. A system used by the consumer for transmission, conveyance, or storage of any fluid, solid, or gaseous substance other than approved water supply. Such a system would include all pipes, conduits, tanks, receptacles, fixtures, equipment, and appurtenances used to produce, convey, or store substances which are or may be polluted or contaminated.
   ISOLATION.
      (1)   The act of confining a localized hazard within a consumer's water system by installing approved backflow prevention assemblies.
      (2)   Disclaimer: The town may make recommendations, upon facility inspection, as to the usages of isolation devices/ assemblies, but does not assume or have responsibility whatsoever for such installations.
   NON-HEALTH HAZARD. An actual or potential threat to the quality of the public or the consumer's water system. A non-health is one that, if introduced into the public water supply system could be a nuisance to water customers but would not adversely affect human health.
   POINT OF DELIVERY. Shall generally be at the back side of the meter, where the meter or backflow prevention assembly (non-metered fire systems) is located. The consumer shall be responsible for all water piping and control devices located on the consumer's side of the point of delivery.
   POLLUTION. An impairment of the quality of the water to a degree which does not create an actual hazard to the public health but which does adversely and unreasonably affect the aesthetic qualities of such water for domestic use.
   POLLUTIONAL HAZARD. An actual or potential threat to the quality or the potability of the public or the consumer's water system but which would not constitute a health or a system hazard, as defined. The maximum degree or intensity of pollution to which the potable water system could be degraded under this definition would cause a nuisance or be aesthetically objectionable or could cause minor damage to the system or its appurtenances.
   POTABLE WATER. Water from any source which has been approved for human consumption by the North Carolina Department of Environmental and Natural Resources (NCDENR).
   PRESSURE VACUUM BREAKER (PVB). An assembly containing an independently operating internally loaded check valve and an independently operating loaded air inlet valve located in the discharge side of the check valve. The assembly is to be equipped with properly located test cocks and tightly closing shutoff valves attached at each end of the assembly. The assembly is designed to protect against a health hazard (i.e., containment) under a back-siphonage condition only. Device must be approved by Foundation for Cross-Connection Control and Hydraulic Research.
   PUBLIC POTABLE WATER SYSTEM. Any publicly or privately owned water system operated as a public utility, under a current NCDENR permit, to supply water for public consumption or use. This system will include all sources, facilities, and appurtenances between the source and the point of delivery such as valves, pumps, pipes, conduits, tanks, receptacles, fixtures, equipment, and appurtenances used to convey, treat, or store potable water for public consumption or use.
   REDUCED PRESSURE PRINCIPLE BACKFLOW PREVENTION ASSEMBLY (RP). An assembly containing within its structure a minimum of two independently acting approved check valves, together with a hydraulically operating, mechanically independent, pressure deferential relief valve located between the check valves and at the same time below the first check valve. The first check valve reduces the supply pressure to a predetermined amount so that during normal flow and at cessation of normal flow, the pressure between the checks shall be less than the supply pressure. In case of leakage of either check valve, the pressure differential relief valve, by discharging to atmosphere, shall operate to maintain the pressure between the check less than the supply pressure.
   REDUCED PRESSURE PRINCIPLE- DETECTOR ASSEMBLY (RPDA). A specially designed assembly composed of a line-size 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 (in U.S. gallons) accurately for very low rates of flow and shall show a registration for all rates of flow. This assembly shall be used to protect against a health hazard (i.e., containment) or a non-health (i.e., pollutant). Device must be approved by the Foundation for Cross-Connection Control and Hydraulic Research.
   SERVICE CONNECTIONS. The terminal end of a service connection from the public potable water system, i.e., where the town loses jurisdiction and control over the water at its point of delivery to the consumer's water system.
   UNAPPROVED WATER SUPPLY. A water supply which has not been approved for human consumption by the NCDENR.
   USED WATER. Any water supplied by a water purveyor from a public water system to a consumer's water system after it has passed through the point of delivery and is no longer under the control of the water purveyor.
   WATER PURVEYOR. The owner, operator, or grantor of authority to operate a public potable water system providing an approved water supply to the public.
(Ord. 17-02, passed 2-20-2017)