For the purposes of this subchapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
AIR-GAP SEPARATION. A physical separation between the free flowing discharge end of a potable water supply pipeline and an open or non-pressure receiving vessel. An APPROVED AIR-GAP SEPARATION shall be at least double the diameter of the supply pipe measured vertically above the overflow rim of the receiving vessel - in no case less than one inch (2.54 cm).
APPROVED.
(1) In reference to a water supply shall mean a water supply that has been approved by the North Carolina Department of Environmental Quality (DEQ).
(2) In reference to air-gap separation, a pressure vacuum breaker, a double check valve assembly, a double check detector assembly, a reduced-pressure principle backflow prevention assembly, a reduced pressure principle detector assembly, or other backflow prevention assemblies or methods shall mean an approval by the city.
BACKFLOW. The undesirable reversal of flow of water or mixtures of water and other liquids, gases, or other substances into the distribution pipes of the consumer or public potable water system from any source or sources.
BACKFLOW PREVENTION ASSEMBLY, APPROVED. An assembly used for containment and/or isolation purposes that has been investigated and approved by the city and has been shown to meet the design and performance standards of the American Society of Sanitary Engineers (ASSE), the American Water Works Association (AWWA), or the Foundation for Cross-connection Control and Hydraulic Research of the University of Southern California. The approval of backflow prevention assemblies by the city is based on a favorable report by the Foundation for Cross-connection Control and Hydraulic Research of the University of Southern California, recommending such an approval. To be approved, an assembly must be readily accessible for in-line testing and maintenance, and shall successfully complete a one-year field evaluation within the city’s water system.
BACKFLOW PREVENTION ASSEMBLY TESTER, CERTIFIED. A person who has proven their competency to the satisfaction of the city. 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, and must hold a current certificate of completion from an approved training program in the testing and repair of backflow prevention assemblies.
BACKFLOW PREVENTION ASSEMBLY, TYPES. 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);
(5) Reduced Pressure Principle-Detector Assembly (Fire System) (RPDA).
BACKFLOW PREVENTION ASSEMBLY, UNAPPROVED. An assembly that has been investigated by the city and has been determined to be unacceptable for installation. Consideration for disapproval and removal from the approved list shall be based upon, but not limited to, the following criteria:
(1) Poor performance standards (significant failure rate);
(2) Lack of, or unavailability of, repair parts; and/or
(3) Poor service or response from assembly’s factory representative(s).
BACKFLOW PREVENTION DEVICE, APPROVED. A device used for isolation purposes that has been investigated by the city and found to be acceptable, based upon it meeting the design and performance standards of the American Society of Sanitary Engineers (ASSE), the American Water Works Association (AWWA), or other equivalent association.
BACK-PRESSURE BACKFLOW. Any elevation in the consumer water system (by pump, elevation of piping, or steam and/or air pressure) above the supply pressure at the point of delivery which would cause - or tend to cause - a reversal of the normal direction of flow.
BACK-SIPHONAGE BACKFLOW. A reversal of the normal direction of flow in the pipeline due to a negative pressure (vacuum) being created in the supply line with the backflow source subject to atmospheric pressure.
CHECK VALVE, APPROVED. 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. The check valve shall permit no leakage in a direction reversed to the normal flow. The closure element (e.g., clapper, poppet, or other design) shall be internally loaded to promote rapid and positive closure. 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 detector assembly.
CONSUMER. Any person, firm, or corporation using or receiving water from the city’s water system.
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. This 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 a public potable water or an auxiliary water supply. The system or systems 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 that creates a potential or actual hazard to the public health through the introduction of hazardous or toxic substances or through the spread of disease by sewage, industrial fluids, or waste.
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. By-pass 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.
DOUBLE CHECK-DETECTOR ASSEMBLY. 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 only 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).
DOUBLE CHECK VALVE ASSEMBLY. 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. This assembly shall only be used to protect against a non-health hazard (i.e., pollutants).
HAZARD, DEGREE OF. Derived from the evaluation of conditions within a system that can be classified as either a pollutant (non-health) hazard or a contamination (health) hazard.
HAZARD, HEALTH. An actual or potential threat of contamination of a physical, hazardous 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.
HAZARD, NON-HEALTH. An actual or potential threat to the quality of the public or the consumer’s potable water system. A NON-HEALTH HAZARD 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.
HAZARD, POLLUTANT. An actual or potential threat to the quality or the potability of the public or the consumer’s potable water system but that 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.
HEALTH AGENCY. The North Carolina Department of Environmental Quality.
INDUSTRIAL FLUIDS. Any fluid or solution that 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; and the like.
INDUSTRIAL PIPING SYSTEM, CONSUMER’S. Any system used by the consumer for transmission of or to confine or store any fluid, solid or gaseous substance other than an approved water supply. Such a system would include all pipes, conduits, tanks, receptacles, fixtures, equipment, and appurtenances used to produce, convey, or store substances that are or may be polluted or contaminated.
ISOLATION. The act of confining a localized hazard within a consumer’s water system by installing approved backflow prevention assemblies.
POINT OF DELIVERY. Generally at the property line of the customer, adjacent to the public street where the city’s mains are located, or at a point on the customer’s property where the meter is located. The customer shall be responsible for all water piping and control devices located on the customer’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.
POTABLE WATER. Wwater from any source that has been investigated by the North Carolina Department of Environmental Quality and which has been approved for human consumption.
PUBLIC POTABLE WATER SYSTEM. Any publicly or privately owned water system operated as a public utility, under a current North Carolina Department of Environmental Quality 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 produce, convey, treat, or store potable water for public consumption or use.
REDUCED PRESSURE PRINCIPLE BACKFLOW PREVENTION ASSEMBLY. An assembly containing within its structure a minimum of two independently acting, approved check valves, together with a hydraulically operating, mechanically independent, pressure differential 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 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 discharge to atmosphere, shall operate to maintain the pressure between the checks less than the supply pressure. The unit shall include tightly closing shut-off valves located at each end of the assembly and each assembly shall be fitted with properly located test cocks. The assembly is designed to protect against a health hazard (i.e., contaminant).
REDUCED PRESSURE PRINCIPLE-DETECTOR ASSEMBLY. 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 only very low rates of flow and shall show a registration for all rates of flow. This assembly shall be used to protect against health hazard (i.e., contaminant).
SERVICE CONNECTIONS. The terminal end of a service connection from the public potable water system, i.e., where the city loses jurisdiction and sanitary control over the water at its point of delivery to the consumer’s water system.
VACUUM BREAKER, ATMOSPHERIC. The terminal end of a service connection from the public potable water system, i.e., where the city loses jurisdiction and sanitary control over the water at its point of delivery to the consumer’s water system.
VACUUM BREAKER, PRESSURE. An assembly containing an independently operating internally loaded check valve and an independently operating loaded air inlet valve located on the discharge side of the check valve. The assembly is to be equipped with properly located test cocks and tightly closing shut-off valves attached at each end of the assembly. This assembly is designed to protect against a health hazard (i.e., contaminant) under a backsiphonage condition only.
WATER PURVEYOR. The owner or operator of a public potable water system, providing an approved water supply to the public.
WATER SUPPLY, APPROVED. Any public potable water supply that has been approved by the North Carolina Department of Environmental Quality.
WATER SUPPLY, AUXILIARY. Any water supply on or available to the premises other that the purveyor’s approved public potable water supply. AUXILIARY WATER SUPPLIES may include water from another purveyor’s public water supply or any natural source such as well, spring, river, stream, and the like. These waters may be polluted, contaminated, or objectionable and constitute an unacceptable water source over which the water purveyor does not have sanitary control.
WATER SUPPLY, UNAPPROVED. A water supply which has not been approved for human consumption by the North Carolina Department of Environmental Quality.
WATER, USED. 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.
(Ord. O-10-24, passed 8-1-2024)