For the purpose of this chapter the following definitions shall apply unless the context clearly indicates or requires a different meaning:
AIR GAP: The unobstructed vertical distance through the free atmosphere between the lowest opening from any pipe or faucet supplying water to a tank, plumbing fixture or other device and the flood level rim of the 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, and in no case less than one inch (1").
APPROVED: Accepted by the department as meeting an applicable specification stated or cited in this section, and as suitable for the proposed use.
AUXILIARY WATER SUPPLY: Any water supply on or available to the premises other than the public potable water supply, including, but not limited to, water from another purveyor's public or private potable water supply, treated effluent, wastewaters, industrial fluids or private wells.
BACK PRESSURE: The flow of water or other liquids, mixtures or substances under pressure into the distribution pipes of a potable water supply system from any source or sources other than the intended source.
BACK SIPHONAGE: The flow of water or other liquids, mixtures or substances into the distribution pipes of a potable water supply from any source other than its intended source caused by the reduction of pressure in the potable water supply system.
BACKFLOW: The reversal of the normal flow of water caused by either back pressure or back siphonage.
BACKFLOW PREVENTER: An assembly or means designed to prevent the reversal of the normal flow of water caused by either back pressure or back siphonage.
CONTAMINATION: An impairment of the quality of the potable water by sewage, industrial fluids or waste liquids, compounds or other materials to a degree which creates an actual or potential hazard to the public health through poisoning or through the spread of disease.
CROSS CONNECTION: Any physical connection or arrangement of piping or fixtures between two (2) otherwise separate piping systems, one of which contains potable water and the other nonpotable water or industrial fluids through which, or because of which, backflow may occur into the potable water system. This would include any temporary connections, such as swing connections, removable sections, four-way plug valves, spools, dummy section of pipe, swivel or changeover devices or sliding multiport tube.
DOUBLE CHECK BACKFLOW ASSEMBLY: An assembly of two (2) independently operating approved check valves with resilient seated shutoff valves on each end of the check valves, plus properly located test cocks for the testing of each check valve. The entire assembly shall meet the design and performance specifications as determined by a recognized laboratory and approved by the department for backflow prevention assemblies. To be approved these devices must be readily accessible for in line testing and maintenance.
POLLUTION: The presence of any foreign substance (organic, inorganic or biological) in the water which tends to degrade its quality so as to constitute a hazard or impair the usefulness or 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 waters for domestic use.
PRESSURE VACUUM BREAKER ASSEMBLY: An assembly containing an independently operating loaded check valve and an independently operating loaded air inlet valve located on the discharge side of the check valve. The assembly shall be equipped with properly located test cocks and resilient seated shutoff valves located at each end of the assembly.
REDUCED PRESSURE BACKFLOW ASSEMBLY: An assembly of two (2) independently acting approved check valves together with a hydraulically operating, mechanically independent differential pressure relief valve located between the check valves and, at the same time, below the first check valve. The unit shall include properly located test cocks and resilient seated shutoff valves at each end of the assembly. The entire device shall meet the design and performance specifications as determined by a recognized laboratory and approved by the department for backflow prevention assemblies. To be approved, these devices must be readily accessible for in line testing and maintenance.
TESTER, RECOGNIZED: A person who has proven his/her competency to the satisfaction of the department. Each person certified to make competent tests or to repair, overhaul and make reports on backflow prevention assemblies shall be conversant with the applicable laws, rules and regulations and have had experience in plumbing or pipefitting or have other qualifications which are equivalent in the opinion of the department.
WATER, NONPOTABLE: Water which is not safe for human consumption.
WATER, POTABLE: Any water which, according to the town, meets nationally recognized standards for human consumption.
WATER, SERVICE CONNECTION: The terminal end of the service line from the public potable water system at its point of delivery to the user's water system. If a meter is installed at the end of the service connection, then the "service connection" shall mean the downstream end of the meter. Unprotected takeoffs from the service line will not be permitted upstream of any meter or any backflow prevention device located at the point of delivery to the user's water system. Service connection shall also include water service connection from a fire hydrant and all other temporary or emergency water service connections from the public potable water system. (Ord. O 12-01, 2-7-2012)