§ 51.20 DEFINITIONS.
   For the purpose of this subchapter, 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 inch.
   APPROVED. Accepted by the Department as either meeting an applicable specification stated or cited in this subchapter, or suitable for the proposed use.
   ASSEMBLY. A mechanical device located between two tightly-closing resilient-sealed shut-off valves with properly located resilient-sealed test cocks designed to prevent backflow.
   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 potable water supply, treated effluent, waste waters or industrial fluids.
   BACKFLOW. The reversal of the normal flow of water caused by either backpressure or backsiphonage.
   BACKFLOW PREVENTER. An approved assembly or means designed to prevent the reversal of the normal flow of water caused by either backpressure or baeksiphonage.
   BACKPRESSURE. Any elevation of pressure in a user’s water supply system, above the pressure of the potable water supply system, which could cause water or other liquids, mixtures or substances to flow from a user’s water supply system into the distribution system of the potable water supply system.
   BACKSIPHONAGE. The flow of water or other liquids, mixtures or substances into the distribution pipes of the potable water supply from any source other than its intended source caused by the reduction of pressure in the potable water supply system.
   CERTIFIED TESTER. A person who has proven his or 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 pipe fitting or have other qualifications which are equivalent in the opinion of the Department.
   CONTAMINATION. An impairment in the quality of potable water, by sewage, industrial fluids, waste liquids, compounds or other materials or fluids, to a degree which creates an actual hazard to the public health by poisoning or the spread of disease.
   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 non-potable 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 multi-port tube.
   DEPARTMENT. The City of Williams Water Department.
   DISTRIBUTION SYSTEM. The network of conduits used to deliver potable water from the source facilities to the user’s water supply system.
   DOUBLE CHECK VALVE ASSEMBLY. An assembly of two independently operating approved check valves with tightly closed 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 recognized laboratory and approved by the Department for backflow prevention assemblies. To be approved, these devices must be readily accessible or in-line testing and maintenance.
   HAZARD, DEGREE OF. The potential risk to the public health and adverse effects of the hazard upon the public potable water distribution system.
   NON-POTABLE WATER. Water which is not safe for human consumption or which is of questionable quality for human consumption.
   NOTICE. A written instrument served by the city, as follows, with time commencing from date of mailing, serving, filing or recording:
      (1)   By the use of ordinary mail to the last known address of the person to whom it is required to be given;
      (2)   By personal service upon the person or his or her lawful representative; or
      (3)   By filing or recording with a Clerk of the Superior Court or County Recorder.
   POLLUTION. The presence of any foreign substance (organic, inorganic or biological) in water which tends to degrade its quality or impair its usefulness to a degree which does not create an actual hazard to the public health, but which does adversely and unreasonably affect such water for domestic use.
   POTABLE WATER. Any water which is safe for human consumption pursuant to the standards set by the state’s Department of Environmental Quality.
   PUBLIC POTABLE WATER SUPPLY SYSTEM. The source facilities and the distribution system under control of the Department to the point where a user’s water supply system commences. A user’s water supply system commences at the discharge point of the service connection.
   REDUCED PRESSURE PRINCIPLE ASSEMBLY. An assembly of two 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 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.
   SERVICE CONNECTION. The terminal end of a service line from the public potable water system at its point of delivery to the user’s water system where the Department loses jurisdiction and sanitary control over the water. If a meter is installed between the user’s water supply system and the public potable water system, the SERVICE CONNECTION shall be the discharge 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.
   USER. The owner, tenant, trustee, mortgagee, receiver or occupier, whether person, corporation, firm or municipality, of property which is connected to the public water system.
(Prior Code, § 8-10.01) (Ord. 720, passed - -1993)