§ 13.16.020  DEFINITIONS.
   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 said 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 (1") inch.
   APPROVED.  Accepted by the Director as meeting an applicable specification stated in this chapter, or as suitable for the proposed use.
   AUXILIARY WATER SUPPLY.  Any water supply on or available to the premises other than the city's public water supply will be considered as an auxiliary water supply. Auxiliary waters may include water from another public or private water supply or any natural source(s) such as a well, spring, river, stream, harbor, and the like, or “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 does not have sanitary control.
   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 backflow.
   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.
   BACKSIPHONAGE. 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.
   CONTAMINATION.  An impairment of the quality of 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 non potable water or industrial fluids of questionable safety, through which, or because of which, backflow may occur into the city's water system. This includes, but it is not limited to, any temporary connections, such as swing connections, removable sections, four (4) way plug valves, spools, dummy section of pipe, swivel or change-over devices or sliding multiport tube.
   CROSS-CONNECTIONS — CONTROLLED.  A connection between the city's water system and a nonpotable water system with an approved backflow prevention assembly properly installed and maintained so that it will continuously afford protection commensurate with the degree of hazard.
   CROSS-CONNECTION CONTROL BY CONTAINMENT.The installation of an approved backflow prevention assembly at the water service connection to any customer's premises where it is physically and economically unfeasible to find and permanently eliminate or control all actual or potential cross-connections within the customer's water system. Alternatively, it shall mean the installation of an approved backflow prevention assembly 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 the cross-connection.
   DIRECTOR.  The Director of Maintenance Services or his or her designee.
   DOUBLE CHECK VALVE ASSEMBLY.  An assembly of two (2) independently operating approved check valves with tightly closing shut-off 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 laboratory and field evaluation program resulting in an approval by a recognized and city approved testing agency for backflow prevention assemblies. To be approved, these assemblies must be readily accessible for in-line testing and maintenance.
   HAZARD, DEGREE OF.  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 and includes the following:
      1.    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, may create a danger to the health and well-being of the water customer.
      2.    HAZARD - PLUMBING.  A plumbing type cross- connection into a customer's potable water system that has not been properly protected by an approved air-gap or approved backflow prevention assembly.
      3.    HAZARD - POLLUTIONAL.  An actual or potential threat to the physical properties of the water system or to the potability of the public or the customer's potable water system which may constitute a nuisance or be aesthetically objectionable or could cause damage to the system or its appurtenances, but would not be dangerous to health.
      4.    HAZARD - SYSTEM.  An actual or potential threat of severe damage to the physical properties of the city's water system or the customers potable water system or of pollution or contamination which would have a protracted effect on the quality of the potable water in the system.
   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 is not limited to: polluted or contaminated water; 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 alkalines, circulating 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, irrigation canals or systems, and the like; 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.
   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 unreasonably affect such waters for domestic use.
   REDUCED PRESSURE PRINCIPLE 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 tightly closing shut-off valves at each end of the assembly. The entire assembly shall meet the design and performance specifications as determined by a laboratory and a field evaluation program resulting in an approval by a recognized and city approved testing agency for backflow prevention assemblies. The assembly shall operate to maintain the pressure in the zone between the two (2) check valves at an acceptable level less than the pressure on the public water supply side of the assembly. At cessation of a normal flow, the pressure between the two (2) check valves shall be less than the pressure on the public water supply 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 assemblies must be readily accessible for in-line testing and maintenance and be installed in location where no part of the assembly will be submerged.
   WATER - NONPOTABLE.  Water which is not safe for human consumption or which is of questionable potability.
   WATER - POTABLE.  Any water which, according to recognized standards, is safe for human consumption.
   WATER - SERVICE CONNECTION.  The terminal end of a service connection from the city's potable 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 any backflow prevention assembly 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.
   WATER SYSTEM.  The water system shall be considered as made up of two (2) parts: The utility system and the customer system.
      1.   The utility system shall consist of the source facilities and the distribution systems and shall include all those facilities of the water system under the complete control of the city, up to the point where the customer system begins.
      2.   The customer system shall include those parts of the facilities beyond the termination of the utility system which are utilized in conveying domestic water to points of use.
('61 Code, § 24B.2)  (Ord. 835, passed - - )