For the purpose 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.
APPROVED. As herein used in reference to a water supply, shall mean a water supply that has been approved by the State Department of Environment, Health, and Natural Resources (Division of Health Services). The term APPROVED as herein used in reference to air-gap separation, a pressure vacuum breaker, an ASSE approved dual check valve assembly, a double check valve assembly, a double check detector assembly, a reduced pressure principal backflow prevention assembly, a reduced pressure principal detector assembly or other backflow prevention assemblies or methods shall mean an approval by the county.
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 county and has been shown to meet 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.
BACKFLOW PREVENTION DEVICE, APPROVED. A device used for isolation purposes that has been shown to meet the design and performance standards of the American Society of Sanitary Engineers (ASSE) and the American Water Works Association (AWWA).
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.
CONSUMER. Any person, firm, and corporation using or receiving water from the county potable water system.
CONSUMER'S WATER SYSTEM. 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(s) 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 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. 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.
DOUBLE CHECK DETECTOR ASSEMBLY (DCDA). 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 (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. This assembly shall only be used to protect against a non-health hazard (i.e. pollutant).
HAZARD, DEGREE OF. Derived from the evaluation of conditions within a system, which can be classified as either a "pollutional" (non-health) or a "contaminant" (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.
HEALTH AGENCY. The North Carolina Department of Environment, Health, and Natural Resources (Division of Health Services), NCDEHNR.
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. The fluids may include, but are not limited to, process waters; chemicals; in fluid form; acids and alkalis; oils, gases; and the like.
POINT OF DELIVERY. Shall generally be 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 the waters for domestic use.
POTABLE WATER. Water from any source which has been investigated by the North Carolina Department of Environment, Health, and Natural Resources (Division of Health Services) and which has been approved for human consumption.
REDUCED PRESSURE PRINCIPAL BACKFLOW PREVENTION ASSEMBLY (RP or RPZ). 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 PRINCIPAL DETECTOR ASSEMBLY (RPDA). A specially designed assembly composed of a line-size approved reduced pressure principal backflow prevention assembly with a specific bypass water meter and a meter-sized approved reduced pressure principal 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 CONNECTION. The terminal end of a service connection from the public potable water system, i.e., where the county loses jurisdiction and sanitary control over the water at its point of delivery to the consumer's water system.
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, which has been investigated and approved by the North Carolina Department of Environment, Health, and Natural Resources. The system must be operating under a valid health permit.
WATER SUPPLY, AUXILIARY. Any water supply on or available to the premises other than the purveyor's approved public potable water supply. These auxiliary waters may include water from another purveyor's public potable water supply or any natural source such as a well, spring, river, stream, or industrial fluids. These waters may be polluted, contaminated, or objectionable and constitute an unacceptable water source over which the water purveyor does not have sanitary control.
(Ord. passed 4-2-2001)