For the purpose of this Chapter, unless the context otherwise requires, the following words and phrases shall have the meanings defined herein.
(A) “AIR GAP” means the unobstructed vertical distance through the free atmosphere between the lowest opening from any pipe or faucet conveying water or waste to a tank, plumbing fixture, receptor, or other assembly and the flood level rim of the receptacle. These vertical, physical separations must be at least twice the diameter of the water supply outlet or at least two (2) inches, whichever is greater.
(B) “APPROVED” means accepted by the City of Unalaska.
(C) “AUXILIARY WATER SUPPLY” means any water supply on or available to the premises other than the City’s approved public water supply. These auxiliary waters may include water from another public potable water supply or any natural source(s), such as a well, spring, river, stream, harbor, and so forth, used waters, or industrial fluids. These waters may be contaminated or polluted, or they may be objectionable and constitute an unacceptable water source over which the City’s public water system does not have sanitary control.
(D) "BACKFLOW" means the undesirable reversal of flow from back siphonage or backpressure in a potable water distribution system as a result of a cross connection.
(E) “BACKPRESSURE” means a pressure, higher than the supply pressure, caused by a pump, elevated tank, boiler, or any other means that may cause backflow.
(F) “BACKSIPHONAGE” means backflow caused by negative or reduced pressure in the supply piping.
(G) “BACKFLOW PREVENTER” means an assembly or means designed to prevent backflow.
(H) “CONTAMINATION” means an impairment of a potable water supply by the introduction or admission of any foreign substance that degrades the quality and creates a health hazard.
(I) “CROSS CONNECTION” means a connection or potential connection between any part of a potable water system and any other environment containing other substances in a manner that under any circumstances would allow such substances to enter the potable water system. Other substances may be gasses, liquids, or solids, such as chemicals, waste products, steam, water from other sources (potable or nonpotable), or any matter that may change the color or add odor to the water.
(J) “CROSS CONNECTIONS - CONTROLLED” means a connection between a potable water system and a nonpotable water system with an approved backflow-prevention assembly properly installed and maintained so that it will continuously afford the protection commensurate with the degree of hazard.
(K) “CROSS CONNECTION CONTROL BY CONTAINMENT” means the installation of an approved backflow-prevention assembly at the water service connection to any consumer’s premises, where it is physically and economically unfeasible to find and permanently eliminate or control all actual or potential cross connections within the consumer’s water system; or it shall mean the installation of an approved backflow-prevention assembly on the service line leading to and supplying a portion of a consumer’s water system where there are actual or potential cross connections that cannot be effectively eliminated or controlled at the point of the cross connection.
(L) “CURB STOP” means the valve on the water service line, set on or about the right- of-way, easement, or property line which separates the City’s ownership from the consumers. This valve is operated by the City through the key box.
(M) “DOUBLE CHECK VALVE ASSEMBLY” means two internally loaded check valves, either spring loaded or internally weighted, installed as a unit between two tightly closing resilient seated shutoff valves and fittings with properly located resilient-seated test clocks. This assembly shall only be used to protect against a nonhealth hazard (that is, a pollutant).
(N) "EXTENDED WATER SERVICE CONNECTION" means a water service connection servicing a consumer whose property is not located adjacent to a road, right-of-way, or easement containing a main water line, making it necessary to locate the meter or key box away from the property line of the premises being served.
(O) “INDUSTRIAL FLUIDS SYSTEM” means any system containing a fluid or solution that may be chemically, biologically, or otherwise contaminated or polluted in a form or concentration, such as would constitute a health, system, pollution, or plumbing hazard, if introduced into an approved water supply. This may include, but not be limited to: polluted or contaminated waters, all types of process waters and used waters originating from the public potable water system that may have deteriorated in sanitary quality, chemicals in fluid form, plating acids and alkalis, circulating cooling waters connected to an open cooling tower, cooling towers that are chemically or biologically treated or stabilized with toxic substances, contaminated natural waters such as wells, springs, streams, rivers, bays, harbors, seas, irrigation canals or systems and so forth, oils, gases, glycerin, paraffins, caustic and acid solutions, and other liquid and gaseous fluids used in industrial or other purposes for fire-fighting purposes.
(P) "KEY BOX" means the service line shut-off that provides access to the curb stop valve located at or near the property line of the subject property or, in the case of extended service connections, located within the dedicated right-of-way or easement.
(Q) “NONPOTABLE WATER” means water that is not safe for human consumption or that is of questionable quality.
(R) “POLLUTION” means the presence of any foreign substance in water that tends to degrade its quality so as to constitute a nonhealth hazard or impair the usefulness of the water.
(S) “POTABLE WATER” means water that is safe for human consumption as described by the public health authority having jurisdiction.
(T) “REDUCED-PRESSURE BACKFLOW PREVENTION ASSEMBLY” means two independently acting approved check valves together with a hydraulically operating, mechanically independent pressure differential relief valve located between the check valves and below the first check valve. These units are located between two tightly closing resilient-seated shutoff valves as an assembly and equipped with properly located resilient- seated test cocks.
(U) “USED WATER” means any water supplied by a water provider from a public potable water system to a consumer’s water system after it has passed through the point of delivery and is no longer under the sanitary control of the water provider.
(V) “TYPES OF HAZARDS” mean:
(1) Degree of hazard. The term is derived from an evaluation of the potential risk to public health and to the adverse effect of the hazard upon the potable water system.
(2) Health hazard. A cross connection or potential cross connection involving any substance that could, if introduced in the potable water supply, cause death, illness, spread disease, or have a high probability of causing such effects.
(3) Plumbing hazard. A plumbing-type cross connection in a consumers potable water system that has not been properly protected by an approved air gap or an approved backflow-prevention assembly.
(4) Nonhealth hazard. A cross connection or potential cross connection involving any substance that generally would not be a health hazard but would constitute a nuisance or be aesthetically objectionable if introduced into the potable water supply.
(5) System hazard. An actual or potential threat of severe damage to the physical properties of the public potable water system or the consumer’s potable water system or of a pollution or contamination that would have a protracted effect on the quality of the potable water in the system.
(W) “WATER SERVICE CONNECTION” means a pipe, key box, meter, and other appurtenances, used to conduct and deliver water from the main to a point at or near the property line of the subject property, except in the case of extended service connections. It is considered the terminal end of a service connection from the public potable water system, that is, where the water provider loses jurisdiction and sanitary control over the water at its point of delivery to the consumer’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. There shall be no unprotected takeoffs from the service line ahead of any meter or backflow-prevention assembly located at the point of delivery to the consumer’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. No. 2001-05, passed 5-8-01; Am. Ord. 2005-18, passed 10-5-05)