§ 51.051  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 a pipe or faucet supplying water to a tank, plumbing fixture or other device and the flood rim of the receptor, or between the lowest opening from any pipe and any contamination or pollution source.
   AWWA. American Water Works Association.
   BACKFLOW or BACK SIPHONAGE. The flow of water or other liquids, mixtures, gases or substances into the municipal water distribution system from any other source than the intended source of the potable water supply.
   BACKFLOW PREVENTER. An assembly or means that prohibits backflow into the potable water supply.
   CROSS-CONNECTION. Any physical arrangement where the potable water supply is connected, directly or indirectly, with any other water supply system, sewer, drain, conduit, tank, pump, plumbing fixture, heat exchanger or other mechanical equipment or device which contains or may contain, contaminated water, sewage or other wastes, liquid or gas of unknown or unsafe quality which may be capable of importing contamination or pollution to the potable water supply as a result of backflow.
   DOUBLE CHECK VALVE ASSEMBLY. A backflow prevention device consisting of two independently acting check valves, internally force loaded to a normally closed position between two tightly closing shut-off valves and with means of testing for tightness.
   DUAL CHECK VALVES. Two independent inline check valve modules installed in one assembly.
   HEALTH HAZARD. An actual or potential threat of contamination of a physical or toxic nature to the public potable water system or the customer’s potable water system that would be a danger to health.
   MANAGER. The General Manager of the Board of Public Works.
   POLLUTION HAZARD. An actual or potential threat of severe damage to the physical properties of the public water system or to the potability of the public or the customer’s potable water system, but which would not constitute a health or system hazard.
   REDUCE PRESSURE PRINCIPAL BACKFLOW PREVENTER. A backflow prevention device consisting of two independently acting check valves, internally force loaded to a normally closed position and separated by an intermediate chamber in which there is an automatic relief means of venting to atmosphere, internally loaded to a normally open position between two tightly closing shut-off valves and with means for testing for tightness of checks and opening of relief means.
   SYSTEM HAZARD. An actual or potential threat of severe damage to the physical properties of the public or the customer’s potable water system or contamination which would have protracted effect on the quality of the potable water in the system.
   VACUUM BREAKER, ATMOSPHERIC TYPE. A vacuum breaker which is not designed to be subject to continuous static line pressure.
   VACUUM BREAKER, PRESSURE TYPE. A vacuum breaker which is designed to be subject to static line pressure.
(Prior Code, § 3-733)  (Ord. 13-98, passed 12-14-1998)