(a) General.
(1) All water services shall be provided with a means of backflow prevention. The type of device will either be a dual check (DC) valve, dual check valve assembly (DCVA) with test assembly, or a reduced pressure zone assembly (RPZ) with test assembly and dump port. The type of device used will generally be dependent on the degree of hazard posed by the customer being served. Engineer/developer shall coordinate with the city to determine the type of device required.
(2) Examples of the various degrees of hazards and required backflow devices are as follows:
a. Low hazard. Any of the following or similar uses unless the use includes a use clearly identified as a higher hazard. These activities shall have a minimum of a dual check valve (DC) installed at the meter service two inches or less.
1. Two-family residential homes (duplexes).
2. Multi-family residential units.
3. Duplexes that have a master meter.
4. Office buildings.
5. Retail stores with only one meter under two inches in diameter.
6. Warehousing (detached and with only restrooms).
7. Churches (with only restrooms).
b. Moderate hazard. Any of the following or similar uses unless the use includes a use clearly identified as a higher hazard. The following is a partial list of facilities, activities and processes which require the installation of an approved double check valve assembly (DCVA).
1. A private water system or building, any portion of which is elevated less than 50 feet above any service connection between such private water system and the public water system.
2. Beauty shops/barber shops.
3. Fire sprinkler or standpipe systems without chemical additives without booster pumps. Fire lines shall also include a properly sized water meter with shut off valves.
4. Gas stations (with no food preparation).
5. Industrial or manufacturing facilities (that do not include a high hazard).
6. Apartment houses or complexes that have a master meter.
7. Mobile home parks/manufactured home parks.
8. Restaurants, bakeries, commercial kitchens or convenience stores with food service with no water supplied fire suppression system.
9. Churches (with kitchen facilities).
c. High hazard. Any of the following uses. The following is a partial list of facilities, activities and processes which require the installation of a reduced pressure zone assembly (RPZ).
1. Any private water system used or designed for use with a booster pump or which may become pressurized for any reason to the extent that backpressure may occur.
2. Any service connection having irrigation tied in (irrigation not on a separate tap) including residential irrigation systems.
3. Any private water system which contains water which has been or is being recirculated.
4. Connection of a non-potable water use (fire lines, fire suppression systems, irrigation systems, cooling towers, auxiliary water supplies, used water, etc.) to a potable water supply.
5. A private water system or building any portion of which is elevated 50 feet or more above any service connection between such private water system and the public water system.
6. Automotive plans and service bays.
7. Beverage bottling plants.
8. Breweries.
9. Campgrounds, RV parks.
10. Canneries, packing houses and other rendering houses.
11. Commercial carwashes.
12. Chemical plants.
13. Churches (containing a baptismal or operating a multi-functional facility).
14. Commercial greenhouses.
15. Commercial laundries.
16. Concrete/asphalt plants.
17. Dairies and cold storage plants.
18. Dentist offices.
19. Dry cleaning.
20. Dye works.
21. Morgues, mortuaries, and embalming facilities.
22. Film laboratories.
23. Fire sprinkler or standpipe systems with chemical additives.
24. Hospitals, clinics, medical buildings.
25. Hotels, apartment houses, public and private buildings or structures 50 feet or more in height.
26. Industrial facilities that utilize water in their industrial process.
27. In-ground irrigation systems, with or without chemical additives.
28. Laboratories.
29. Law care companies.
30. Malls, strip malls, or multi-tenant strip malls (frequent tenant change and photo labs, etc.) that are master metered.
31. Master metered buildings or facilities with multi-use tenants.
32. Metal processing plants.
33. Nursing homes.
34. Oil and gas production, storage or transmission properties.
35. Paper and paper products plants.
36. Pest control (exterminating and fumigating).
37. Pharmaceutical plants.
38. Photo labs.
39. Plating plants.
40. Power plants.
41. Radioactive materials or substances, plants or facilities handling.
42. Restaurants, bakeries, commercial kitchens, convenience stores with food services, any of which have water-supplied fire suppression systems.
43. Rubber plants (natural or synthetic).
44. Sand and gravel plants.
45. Schools and colleges.
46. Swimming pools, spas, hot tubs, with fixed water lines.
47. Tanks or reservoirs filled by water from public water supply.
48. Tire manufacturers.
49. Truck wash facilities.
50. Veterinary hospitals, clinics, offices.
51. Wastewater treatment plants, lift stations, and storm drain facilities.
52. Waterfront facilities and industries.
(b) Backflow prevention assemblies shall conform to USC Foundation for Cross Connection Control and Hydraulic Research and to the following requirements:
(1) Dual check valve (DC) shall meet the requirements of ASSE Std. #1024.
(2) The size and type shall be as indicated by the degrees of hazard as approved by the city.
(3) Double check valve assembly (DCVA) in conformance with AWWA C510 and ASSE 1015.
(4) Reduced pressure zone assembly (RPZ) in conformance with AWWA C511 and ASSE 1013.
(5) Assembly unit shall include a flow detector consisting of an auxiliary line with an approved backflow preventer and water meter. Flow detector assembly shall comply with ASSE 1047 or 1048.
(6) Service shall be for cold water.
(7) End connection shall be threaded or flanged.
(8) Assembly shut-off valves shall be:
a. Two-inch and under. 1/4 turn, full port, resilient seated, bronze ball valve.
b. Over two-inch. OS&Y resilient seated gate valves.
(9) Valves shall be internally epoxy coated in accordance with AWWA C550.
(Ord. of 11-7-16; No. 10-16)