The following terms and phrases when used in this article shall have the meaning ascribed to them in this section except where the context clearly indicates a different meaning. Words used in the present tense shall include the future, and the singular number includes the plural, and the plural the singular.
(1) 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 such vessel. An approved air-gap shall be at least double the diameter of the supply pipe; measured vertically, above the top of the rim of the vessel and, in no case, less than two inches. When an air-gap is used at the service connection to prevent the contamination or pollution of the public potable water system, an emergency bypass shall be installed in the bypass system which shall include an approved back-flow prevention device.
(2)Approved: Accepted by the director of utilities as meeting an applicable specification stated or cited in this section, or as suited for the proposed use.
(3)Auxiliary water supply: 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 spring, river, stream, harbor, or the like, or “used waters” or “industrial fluids”. These waters may be polluted or contaminated or they may be objectionable and constitute an unacceptable water source over which the water purveyor does not have sanitary control.
(4)Backflow: The flow of water or other liquid, mixture or substance under pressure into the distributing pipes of a potable water supply system from any source or sources other than its intended source.
(5)Backflow preventer: A device or means designated to prevent backflow or back-siphonage.
(6)Back-siphonage: The flow of water or other liquid, mixture or substance into the distributing pipes of a potable water supply stream from any source other than its intended source caused by the sudden reduction of pressure in the potable water supply system.
(7)Contamination: Any impairment of the quality of potable water by sewage, industrial fluids, waste liquids, compounds, or other materials to a degree which creates a potential actual hazard to the public health through poisoning or through the spread of disease.
(8)Cross-connection: Any physical connection or arrangement of piping or fixtures between two otherwise separate piping systems, one of which contains potable water and the other nonpotable water or industrial fluids of questionable safety, through which, or because of which, backflow or back-siphonage may occur into the potable water system. A water service connection between a public potable water distribution system and a customer’s water distribution system which is cross-connected to a contaminated fixture, industrial fluid system, or with a potentially contaminated supply or auxiliary water system, constitutes one type of cross-connection. Other types of cross-connections include connectors such as swing connections, removable sections, four-way plug valves, spools, dummy sections of pipe, swivel or changeover devices, sliding multiport tube, solid connections, and the like.
a.Cross-connection control by containment: The installation of an approved backflow prevention device at the water service connection to any customer's premises where it is not physically and economically feasible to find and permanently eliminate or control all actual or potential cross-connections within the customer's water system; or the installation of an approved backflow prevention device on the service line leading to and supplying a portion of a customer's water system where there are actual or potential cross-connections which cannot be effectively eliminated or controlled at the point of cross-connection.
b.Cross-connection controlled: A connection between a potable water system and a nonpotable water system with an approved backflow prevention device properly installed that will continuously afford the protection commensurate with the degree of hazard.
(9)Double check valve assembly: An assembly of two (2) independently operating approved check valves with tightly closing shutoff valves on each side 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 and approval of a recognized and city-approved testing agency for backflow prevention devices. To be approved, these must be readily accessible for in-line maintenance and testing.
(10)Hazard, degree of. The term is derived from an evaluation of the potential risk to public health and the adverse effect of the hazard upon the potable water system, and shall include:
a.Hazard, health: Any condition, device or practice in the water supply system and its operation which could create or, in the judgment of the director of utilities, may create a danger to the health and well-being of the water consumer. An example of a “health hazard” is a structural defect, including a cross-connection, in the water supply system.
b.Hazard, plumbing: A plumbing-type cross-connection in a consumer's potable water system that has not been properly protected by a vacuum breaker, air-gap separation, or backflow prevention device. Unprotected plumbing-type cross-connections are considered to be a health hazard.
c.Hazard, pollutional: An actual or potential threat to the physical properties of the water system or to the potability of the public or the consumer's potable water system but which would constitute a nuisance or be aesthetically objectionable or could cause damage to the system or its appurtenances, but would not be dangerous to health.
d.Hazard, system: 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 pollutant or contaminant which would have a protracted effect on the quality of the potable water in the system.
(11)Industrial fluids system: Any system containing a fluid or solution which may be chemically, biologically or otherwise contaminated or polluted in a form or concentration such as would constitute a health, system, pollutional or plumbing hazard if introduced into an approved water supply. This may include, but shall not be limited to: polluted or contaminated waters; all types of process waters and “used waters” originating from the public potable water system which may have deteriorated in sanitary quality; chemicals in fluid form; plating acids and alkalis; circulated cooling waters connected to an open cooling tower and/or cooling waters that are chemically or biologically treated or stabilized with toxic substances; contaminated natural waters such as from wells, springs, streams, rivers, bays, harbors, irrigation canals or systems, and the like; and oils, gases, glycerine, paraffins, caustic and acid solutions, and other liquid and gaseous fluids used in industrial or other purposes or for fire-fighting purposes.
(12)Pollution: The presence of any foreign substance (organic, inorganic or biological) in 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 reasonably affect such waters for domestic use.
(13)Pressure-type vacuum breaker: An assembly used to isolate entire irrigation lines from potable water systems. It has the ability to withstand supply pressure for long periods and to prevent backflow of toxic and nontoxic water into the potable water system in back-siphonage conditions. To be approved, these devices must be readily accessible for in-line maintenance and testing.
(14)Purveyor or Water purveyor. The owner or operator of the public potable water system supplying an approved water supply to the public.
(15)Reduced pressure principle device: An assembly of two (2) independently operating approved check valves with an automatically operating differential relief valve between the two (2) check valves, tightly closing shutoff valves on either side of the check valves, plus properly located test cocks for the testing of the check and relief valves. The entire assembly shall meet the design and performance specifications and approval of a recognized and city approved testing agency for backflow prevention assemblies. The device shall operate to maintain the pressure in the zone between the two (2) check valves at a level less than the pressure on the public water supply side of the device. At cessation of normal flow, the pressure between the two (2) check valves shall be less than the pressure on the public water supply system side of the device. In case of leakage of either of the check valves, the differential relief valve shall operate to maintain the reduced pressure in the zone between the check valves by discharging to the atmosphere. When the inlet pressure is two (2) pounds per square inch or less, the relief valve shall open to the atmosphere. To be approved, these devices must be readily accessible for in-line maintenance and testing and be installed in a location where no part of the device will be submerged.
a.Water, nonpotable: Water which is not safe for human consumption or which is of questionable potability.
b. Water, potable: Any water which, according to recognized standards, is safe for human consumption.
c. Water, service connections: The terminal end of a service connection from the public potable water system; that is, where the water purveyor loses jurisdiction and sanitary control over the water at its point of delivery to the customer's water system. If a meter is installed at the end of the service connection, the service connection shall mean the downstream end of the meter. There should be no unprotected takeoffs from the service line ahead of any meter or backflow prevention device located at the point of delivery to the customer'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.
d.Water, used: Any water supplied by a water purveyor 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 purveyor.
(17)Water system: The water system shall be considered as made up of two (2) parts: The customer system and the utility system.
a. The “customer system” shall include those parts of the facilities beyond the termination of the utility distribution system which are utilized in conveying utility-delivered domestic water to points of use.
b. The “utility system” shall consist of the source facilities and the distribution system; and shall include all those facilities of the water system under the complete control of the utility, up to the point where the customer's system begins (meter). The “source” shall include all components of the facilities utilized in the production, treatment, storage and delivery of water to the distribution system. The “distribution system” shall include the network of conduits used for the delivery of water from the source to the customer's system.
(Ord. No. 90-51, § 1, 11-7-90; Ord. No. 13-032, § 2, 11-9-13)
