The following words shall have the meanings set forth:
Air gapmeans the unobstructed vertical distance through the free atmosphere between the lowest opening from any pipe or faucet supplying water to a tank, plumbing fixture, other device or vessel and the flood level rim of said vessel.
Approvedmeans accepted by the water purveyor as meeting the applicable specification or procedures as stated or cited in this chapter.
Approved backflow prevention device (assembly)means a device listed in the latest University of Southern California, Foundation for Cross-Connection Control and Hydraulic Research “List of Approved Backflow Prevention Assemblies.”
Auxiliary water supplymeans any water supply on or available to the premises other than the water purveyor’s approved potable water supply. These auxiliary water supplies may include, but are not limited to, water from another purveyor’s potable water supply or any natural source(s) such as a well, spring, river, stream, pond, lake, etc., or “used waters” or “industrial fluids.” These waters may be polluted or contaminated, or may be objectionable and constitute an unacceptable water source over which the water purveyor does not have sanitary control.
Backflowmeans the undesirable reversal of, or the possibility thereof, the direction of flow of the water or mixtures of water and other liquid, gases, or other substances into the distribution pipes of the potable water supply from any source or sources caused by back pressure and/or back siphonage.
Back pressuremeans backflow caused by a pump, elevated tank, boiler, or “head” in pipe, or any means that could create greater pressure within a piping system than that which exists within the potable water supply.
Back siphonagemeans the reverse flow of, or potential thereof, water or other liquids, mixtures, gases or substances into the distribution pipes of a potable water supply system caused by negative or subatmospheric pressure in the potable water supply system.
Check valvemeans a self-closing device which is designed to permit the flow of fluids in only one direction. A single check valve is not an approved backflow prevention device.
Containment.Protection by containment shall mean the installation of an approved backflow prevention device, or method, on the water service line(s) serving any premises, location, facility or area. Protection by containment shall be used when the potable water system may be contaminated or polluted by substances used or stored within a building or premises.
Contaminationmeans 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 a potential hazard to the public health through a reduction in water quality or through the spread of disease or hazardous materials.
Critical levelmeans the critical level or other regulated “C/L marking” on a backflow prevention device or vacuum breaker which is a point conforming to approved standards and established by testing laboratory, which determines the minimum elevation above the flood level rim of the fixture, highest point of usage, or receptacle served at which the device may be installed. When a backflow prevention device does not bear a critical level marking, the bottom of the vacuum breaker, combination valve, or the bottom of any such approved device shall constitute the critical level.
Cross-connectionmeans any physical arrangement whereby a potable water supply is connected, directly or indirectly, with any other water supply system, sewer, drain, conduit, tank, plumbing fixture, or other device which contains, or may contain, contaminated water, sewage, or other waste, liquid or gas of unknown or unsafe quality which may be capable of imparting contamination or pollution to the potable water supply as a result of backflow. Bypass arrangements, jumper connections, removable spools, swivel or changeover devices, four-way valve connections, and other temporary or permanent devices through which, or because of which, backflow could occur are included in the definition of cross-connection.
Cross-connections, controlledmeans a connection made between a potable water system and a nonpotable water system with an approved backflow prevention device, properly installed and tested in accordance with this chapter, will continuously afford the protection commensurate with the degree of hazard as determined by the Director of Public Works of the City.
Double check valve assembly (“DC” or “DCVA”)means an assembly of two independently operating approved check valves between two tightly closing (resilient seated) shut-off valves, plus four properly located test cocks for the testing of each check valve. The entire assembly shall be an approved backflow prevention device.
Flood level rimmeans the edge of the receptacle from which liquid overflows.
Hazard, degree ofis the term derived from an evaluation of the potential risk to public health and the adverse effect of the hazard upon the potable water system as determined by the Director of Public Works of the City.
Hazard, healthmeans any condition, device, or practice in the water supply system and its operation which could create, or in the judgment of the water purveyor may create, a danger to the health and well-being of a water consumer. An example of a health hazard is a structural defect, including cross-connections, in a water supply system, or a direct connection of a potable water supply line to a sanitary sewer.
Hazard, plumbingmeans a plumbing type cross-connection in a potable water system that has not been properly protected by an air-gap separation or an approved backflow prevention device. Unprotected plumbing type cross-connections are deemed to be a health hazard.
Hazard, pollutionmeans 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 a threat to life or be dangerous to health as determined by the Director of Public Works of the City.
Hazard, systemmeans an actual or potential threat of severe damage to the physical properties of the potable water system or the consumer’s potable water system or of a pollution or contamination which would have a protracted effect on the quality of the potable water in the system caused by a cross-connection.
Industrial fluids systemmeans any system containing a fluid or solution which may be chemically, biologically, radiologically, or otherwise contaminated or polluted in a form or concentration that 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” originated from the 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 towers that are chemically or biologically treated or stabilized with toxic substances; contaminated natural waters such as from wells, springs, streams, rivers, lakes, dams, ponds, retention pits, irrigation canals or system, etc.; oils, gases, glycerin, glycols, paraffins, caustic and acid solutions and other liquid and gaseous fluids used in industrial or other purposes or for fire-fighting purposes.
Isolationmeans the control of cross-connections within a building’s plumbing system by the installation of approved backflow prevention devices or methods at or mean the potential sources of pollution or contamination.
Nonpotable watermeans water that is not safe for human consumption or that does not meet the requirements set forth in the State of Colorado Primary Drinking Water Regulations.
Pollutionmeans the presence of any foreign substance (organic, inorganic, radiological or biological) in the water that may degrade the water quality so as to constitute a nonhealth type hazard or impair its usefulness.
Potable watermeans water free from impurities in amounts sufficient to cause disease or harmful physiological effects. The bacteriological, chemical and radiological quality shall conform to State of Colorado Primary Drinking Water Regulations.
Reduced pressure principle device or reduced pressure zone device “RPZ”means an assembly of two independently operating approved check valves with a hydraulic automatic operating differential relief valve between the two check valves. The assembly shall be located between two tightly closing (resilient seated) shut-off valves and have four properly located test cocks for the testing of the check and relief valves. The entire assembly shall be an approved backflow prevention device.
Submerged inletmeans a water pipe or extension thereof from a potable water supply terminating below the flood level rim of a tank, vessel, fixture or appliance which may contain water of questionable quality, waste or other contaminant or pollutant.
Vacuummeans any pressure less than atmospheric pressure.
Vacuum breaker, atmospheric nonpressure typemeans a vacuum breaker consisting of an air inlet opening and a nonloaded floating check disk valve designed to prevent back siphonage only. The device shall not be subjected to continuous static line pressure or back pressure or be installed where it would be under pressure for more than 12 continuous hours.
Vacuum breaker, pressure typemeans a vacuum breaker, designed to prevent back siphonage only, consisting of a spring-loaded check valve, a spring-loaded air inlet opening, a tightly closing shut-off valve on each side of the device and two appropriately located test cocks. The device shall not be subjected to back pressure. The entire assembly shall be an approved backflow prevention device.
Water service connectionmeans the terminal end of the water purveyor’s service connection from the potable water distribution system; i.e., where the water purveyor loses jurisdiction and sanitary control over the water as its point of delivery to the customer’s stop box or shut-off valve or meter, whichever comes first from the water main. If a meter is installed at the end of the service connection, 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 device located at the point of delivery to the customer’s water system. This shall include irrigation systems and fire sprinkler systems. Service connection shall also include water service connection from a hydrant and all other temporary or emergency water service connections from the potable water system. For customers outside the water purveyor limits, “water service connection” shall mean the terminal end of the water purveyor’s service connection from the potable water system to the customer’s corporation stop.
(Res. 89-99, 8-4-99; Res. 92-94, 10-19-94. Code 1994 App. F § 3)