1) Abbreviations: Acceptable abbreviations for showing types of new and existing pipe materials on the plans are as follows:

2) Air Gap Separation: A physical vertical separation between the free-flowing discharge end of a potable water supply and the rim of any open, non­ pressurized receiving vessel.

3) Approved Backflow Prevention Assembly: An assembly that has been investigated and approved by the Oregon Health Authority - Drinking Water Services (OHA-DWS) for preventing backflow.

4) Backflow: The flow of water or other fluids in a direction opposite to the normal flow. (See Back-Siphonage.)

5) Back-Siphonage: The flowing back of used, contaminated, or polluted water from a plumbing fixture or vessel into a water supply pipe due to a negative or reduced pressure in such pipe.

6) Building Supply: The pipe carrying potable water from the water meter or other source of water supply to a building or other point of use or distribution on the lot. Building supply shall also mean customer line.

7) Cross Connection: Any connection or arrangement, physical or otherwise, between a potable water supply system and any plumbing fixture or any tank, receptacle, equipment or devise, through which it may be possible for non­ potable, used, unclean, polluted and contaminated water, or other substances, to enter into any part of such potable water system under any condition.

8) Customer Water Supply System: The water supply system of a building, premises or private system consists of the all supply pipe from the customer side of the water meter, including water service pipes, and the necessary connecting fittings, control valves, pipe and all appurtenances carrying or supplying potable water in or adjacent to the building premises served.

9) Distribution Mains: All mains which are not designated as transmission mains, and which are used for supply the individual consumer. As a general rule these are the smaller mains in the water supply system.

10) Distribution System: Distribution main pipelines, pumping stations, valves and ancillary equipment used to transmit water from the supply source to the service line.

11) Double Check Valve Assembly: An assembly composed of two single, independently acting check valves, including tightly closing shut-off valves located at each end of the assembly and fitted with properly located test ports.

12) Double Detector Check Valve Assembly: A line-sized approved double check valve assembly with a parallel meter and meter-sized approved double check valve assembly. The purpose of this assembly is to provide double check valve protection for the distribution system and at the same time provide partial metering of the fire system showing any system leakage or unauthorized use of water.

13) Fire Hydrant Assembly: Fire hydrant, hydrant lead, mainline hydrant valve, mainline tee, and thrust restraint at the hydrant and the mainline tee.

14) Fire Protection Services: A connection to the public water main intended only for the extinguishment of fires and flushing necessary for its proper maintenance.

15) Fixture Unit Equivalents: The unit flow or demand equivalent of plumbing fixtures as tabulated in the Oregon Plumbing Specialty Code.

16) Health Division: Oregon Department of Human Resources Health Division.

17) Hydrant Lead: The line connecting the fire hydrant to the City main or private fire line.

18) Irrigation Service: A metered connection intended for seasonal use and delivering water which is not discharged to the sanitary sewer.

19) ISO: Insurance Service Office.

20) Mainline Hydrant Valve: The isolation valve between the City water main or private fire line and the fire hydrant.

21) Oregon Plumbing Specialty Code: The Uniform Plumbing Code, current edition as revised by the State of Oregon, called the "Oregon Plumbing Specialty Code."

22) Potable Water: Water which satisfactory for drinking, culinary and domestic purposes and meets the requirements of the health authority having jurisdiction.

23) Private Distribution System: A privately owned and maintained water distribution system serving an industrial or commercial subdivision or a multi­ building development on a single lot served through a master meter installed at the approved location. Private distribution systems must have a single entity responsible for the system. Resale of water without written approval of the City shall be prohibited.

24) Service Line: The waterline or pipe extending from the distribution main to the water meter, backflow prevention device, or private fire system double check valve.

25) Transmission Mains (Supply Lines): Mains which are used for transporting water from the source of supply and storage reservoirs to the centralized point of distribution and distribution reservoirs. Transmission mains may or may not supply individual consumers, but they are sized and located to transport water from centralized points of distribution to various points of interconnection with the grid system and centralized points of consumption.

26) Water Main: A water-supply pipe for public or community use.

27) Water Master Plan: The Water System Master Plan for the City of Silverton, Oregon, most recent revisions.