For the purpose of this subchapter the following definitions shall apply unless the context clearly indicates or requires a different meaning.
AIR GAP SEPARATION. An unobstructed vertical distance through the atmosphere between the lowest opening from any pipe or faucet supplying water from any source to a tank, plumbing fixture, or other device and the flood level rim of the receptacle. An approved air gap separation shall be at least double the diameter of the supply pipe. In no case shall the air gap separation be less than one inch. An approved, air gap separation is an effective method to prevent backflow and shall be considered as a backflow prevention assembly.
ATMOSPHERIC VACUUM BREAKER. A device used to prevent back siphonage which is designed so as not to be subject to static line pressure.
BACK PRESSURE. Any elevation of pressure in the downstream piping system caused by pumps, elevation of piping, or steam and/or air pressure above the supply pressure at the point of consideration, which would cause a reversal of the normal direction of flow.
BACK SIPHONAGE. 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.
BACKFLOW PREVENTION ASSEMBLY- APPROVED. An assembly that has been investigated
and approved by the Town of Grimesland Public Works Department and has been approved 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.
BACKFLOW. Any reverse flow of water, gas or any other liquid substance or combination into the public water system from any source due to an unprotected cross-connection.
CERTIFIED TESTER. Any individual person who has proven his or her competency to test, repair and overhaul backflow prevention assemblies. This person must hold a certificate of completion from a certified training program in the testing and repair of back flow prevention assemblies and cross-connection control. This certificate shall be on file with the Public Works Department.
CONSUMER/CUSTOMER. Any person, firm, or corporation using or receiving water from the Town of Grimesland public water system.
CONTAINMENT. The prevention of back flow from a private water system by an approved, properly functioning backflow prevention assembly which is installed operated and maintained in accordance with the provisions of this subchapter.
CONTAMINATION. An impairment of the quality of the water to a degree, which creates an actual hazard to the public health through poisoning or through the spread of disease.
CROSS-CONNECTION. Any actual or potential connection or piping arrangement between a public or a consumer's potable water system and any other source or system through which it is possible to introduce into any part of the potable system any used water, industrial fluids, gas or substance which could be harmful or hazardous to the potable water system.
DOUBLE CHECK VALVE ASSEMBLY (DCVA). An assembly composed of two single, independently acting, approved check valves, including tightly closing shut-off valves located at each end of the device and suitable connections for testing the water tightness of each check valve.
DOUBLE CHECK-DETECTOR VALVE ASSEMBLY (DCDA). An assembly composed of an approved double check valve assembly with a bypass water meter and a meter-sized approved double check valve device. The meter shall register accurately for very low flow rates and shall register all flow rates.
HAZARD DEGREE. The evaluation of a hazard within a private water system as moderate or severe.
HAZARD - SEVERE. An actual or potential threat of contamination to the public water system or to a customer's potable water system that could cause serious illness or death.
HAZARD - IMMINENT. An actual threat of contamination to the public water system that could cause serious illness or death.
HAZARD - MODERATE. One that presents foreseeable and significant potential for pollution, nuisance, aesthetically objectionable or other undesirable alterations of the drinking water supply.
HEALTH HAZARD.
(1) The term shall mean 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.
(2) DANGERS TO HEALTH. Examples of waterborne health hazards include but are not limited to:
(a) BIOLOGICAL - microorganisms and pathogens like Cryptosporidium, typhoid, cholera and E. Coli;
(b) CHEMICAL - lead, mercury and other heavy metals, organic compounds, other toxins and hazardous substances; and
(c) PHYSICAL - radioisotopes/radionuclides.
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 water for domestic use.
POTABLE WATER. Water from any source which has been approved for human consumption by the appropriate agency of the State of North Carolina, Town of Grimesland and/or local health agencies.
PRESSURE VACUUM BREAKER. An assembly suitable for continuous pressure, to be used to provide protection against back siphonage.
PRIVATE WATER SYSTEM. Any water system located on the customer's premise, whether supplied by public potable water or an auxiliary water supply. The system or systems may be either a potable water system or an industrial piping system.
PUBLIC WATER SYSTEM. The potable water system owned and operated by the Town of Grimesland. This system includes all distribution mains, lines, pipes, connections, storage tanks and other facilities conveying potable water to the service connections of each customer.
PUBLIC WORKS DEPARTMENT. A branch of the town with employees that are designated by The Town Council to administer and enforce the provisions of this subchapter.
REDUCED PRESSURE ZONE ASSEMBLY (RPZ). An approved, properly functioning assembly containing two, independently acting check valves 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 assembly must include properly located test cocks and tightly closing shut-off valves at each end of the assembly. This assembly is designed to protect against a severe hazard.
RESIDENTIAL DUAL CHECK (RDC). An assembly, without test cocks or ports, containing two independently operating spring loaded, poppet type check valves, in series, which can be easily removed and replaced. This assembly is suitable for installation in a water meter vault or pit, below ground.
SERVICE CONNECTION. The terminal end of a service connection from the public potable water system, i.e., where the water purveyor loses jurisdiction and sanitary control over the water at its point of delivery to the consumer's water system.
USED WATER. Any water supplied by a water purveyor from a public water system to a consumer's water system after is has passed through the point of delivery and is no longer under the control of the water purveyor.
WATER PURVEYOR. Owner or operator of a public potable water system providing an approved water supply to the public.
WATER SUPPLY-AUXILIARY. Any water supply on or available to the customer's premises other than the purveyor's approved public potable water supply. The auxiliary water may include water from another purveyor's public potable water supply or any natural source such as a well, spring, river, stream, and the like, and used or objectionable.
WATER SUPPLY-UNAPPROVED. Any water supply, which has not been approved for human consumption by the North Carolina Department of Human Resources.
(Res. passed 9-11-2012)