Sec. 37-144. Backflow prevention methods.
A. Approved backflow prevention method. Unless otherwise specifically designated by the Director, an approved backflow prevention method shall be one of the following types:
1. Air gap: An unobstructed vertical distance through the free atmosphere between the opening of any pipe or faucet supplying potable water to a tank, plumbing fixture or other device and the flood level rim of said tank, plumbing fixture or other device. An approved air gap must be at least double the diameter of the supply pipe or faucet and in no case less than one inch.
2. Reduced pressure principle assembly (hereafter "RP"): An assembly containing two independently acting approved checkvalves together with a hydraulically operating, mechanically independent pressure differential relief valve located between the checkvalves and at the same time below the first checkvalve. The assembly must include properly located test cocks equipped with brass plugs and tightly closing resilient seated shut-off valves at each end of the assembly.
3. Pressure vacuum breaker assembly (hereafter "PVB"): An assembly containing an independently operating, loaded checkvalve and an independently operating, loaded air inlet valve located on the discharge side of the checkvalve. The assembly must be equipped with properly located test cocks fitted with brass plugs and tightly closing resilient seated shut-off valves located at each end of the assembly.
4. Double checkvalve assembly (hereafter "DC"): An assembly composed of two independently acting, approved checkvalves, including tightly closing resilient seated shut-off valve at each end of the assembly and fitted with properly located test cocks equipped with brass plugs.
B. Requirements for new services and existing services. An approved backflow prevention method is required for the activities or facilities listed in this subsection that are connected to the public water system. The backflow prevention method must be in accordance with that specified in the USC manual. The location must be as close as practicable to the point of service delivery except that the customer may request that the approved backflow prevention method be located internally within the activity or facility. The customer must demonstrate that the proposed location will adequately protect the public water supply as well as satisfy the applicable requirements of this article. For purposes of this subsection, the listed facilities, equipment or conditions must be as defined in the USC manual, or if not listed in the USC manual, must be as defined in the City of Phoenix Zoning Ordinance or Construction Code:
Industrial facilities:
1. Aircraft and missile plants (air gap or RP).
2. Automotive plants (air gap or RP).
3. Beverage bottling plants (air gap, RP or DC).
4. Breweries (air gap or RP).
5. Canneries, packing houses, reduction plants and food processing plants (air gap or RP).
6. Chemical plants—manufacturing, processing, compounding or treatment (air gap or RP).
7. Dairies and cold storage plants (air gap, RP or DC).
8. Film laboratories (air gap or RP).
9. Laundry and dye works (air gap or RP).
10. Metal manufacturing, cleaning, processing and fabricating plants (air gap, RP or DC).
11. Oil and gas production, storage or transmission properties (air gap or RP).
12. Paper and paper products plants (air gap or RP).
13. Plating plants (air gap or RP).
14. Power plants (air gap or RP).
15. Radioactive materials or substances—plants or facilities handling (air gap or RP).
16. Rubber plants—natural or synthetic (air gap or RP).
17. Sand and gravel plants (air gap or RP).
18. Semiconductor manufacturing facilities (air gap or RP).
19. Sewage and storm drain facilities, reclaimed water (air gap or RP).
Medical facilities:
20. Research laboratories (air gap or RP).
21. Hospitals, medical buildings, sanitariums, morgues, mortuaries, autopsy facilities, nursing and convalescent homes and clinics (air gap or RP).
22. Veterinary hospital, animal research, or animal grooming shops (air gap or RP).
23. Medical marijuana grow facilities (air gap or RP).
Commercial and educational facilities:
24. Buildings: Any structure having a cross connection in violation of the Phoenix Plumbing Code or water operated sewage pumping facilities, auxiliary water supplies or other like sources of contamination which would create a potential hazard to the public water system (air gap, RP or DC).
25. Carwash facilities (air gap or RP).
26. Motion picture studios (air gap or RP).
27. Multi-storied buildings having booster pumps or above-ground storage tanks (air gap, RP or DC).
28. Multiple services—interconnected (air gap, RP or DC).
29. Mobile home parks (RP or DC).
30. Recreational vehicle parks (RP or DC).
31. Schools and colleges with laboratories (air gap or RP).
32. Retail shopping centers and strip malls; retail and industrial shell buildings (when one service supplies more than one tenant) (RP).
33. Supermarkets, butcher shops, and restaurants (air gap or RP).
34. Retail and wholesale nurseries (air gap or RP).
35. Equestrian properties (air gap or RP).
Portable or temporary services or equipment:
36. Construction sites or construction water services (air gap or RP).
37. Mobile equipment utilizing public potable water (i.e., water trucks, street sweepers, hydro-vacs, etc.) (air gap or RP).
38. Portable insecticide and herbicide spray tanks (air gap or RP).
Miscellaneous activities and equipment:
39. Auxiliary water systems (air gap or RP).
40. Chemically contaminated water systems (air gap or RP).
41. Fire systems:
a. Class 1 or 2: Backflow prevention assembly is required. Check valve assemblies required by the Phoenix Fire Code must be inspected, tested and maintained at least annually to verify the valves are properly installed and functioning. Annual flow and valve confidence tests must be performed by a tester who is permitted by the City Fire Marshal to test or maintain fire lines or fire sprinkler systems. Test results, on forms approved by the City, shall be provided to the Director and the City Fire Marshal within 30 days following the inspection. Any fire sprinkler system which fails must be repaired as required by the Fire Code.
b. Class 3, 4, 5, or 6 (RP).
42. Industrial fluid systems. Any industrial fluid system interconnected with the public water supply and containing any 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, pollution or plumbing hazard if introduced into an approved water supply (RP or DC).
43. Irrigation systems:
a. System using a chemical injection system (RP).
b. System having elevated areas which are higher than six inches below the PVB or multiple services (RP).
c. System not subject to backpressure (PVB).
44. Restricted, classified or other closed facilities including civil works (air gap or RP).
45. Solar heating systems—direct and auxiliary (RP).
Exception: Once-through solar heating systems.
C. The Planning and Development Director will determine on a case-by-case basis backflow prevention requirements for any facility or activity not listed in this section in order to prevent contamination or pollution of the public potable water system.
D. All assemblies must be accessible for testing and maintenance. A reduced pressure principle assembly or double check valve assembly may not be installed in a basement, meter box, pit, or vault. A pressure vacuum breaker assembly must be installed above ground.
E. Unless a cross connection problem is specifically identified, or except as otherwise provided in this article, the requirements of this article do not apply to single-family residences used solely for residential purposes.
F. Close as practicable means the point nearest the point of service delivery where the assembly can be installed. Where the assembly installation location may interfere with obstacles such as driveways and sidewalks, then close as practicable means the nearest point after the obstacle, but in no event beyond the first tap.
G. An air gap separation must be located as close as practicable to the customer’s point of service delivery. All piping between the customer’s connection and receiving tank must be entirely visible unless otherwise approved by the Planning and Development Director. (Ord. No. G-6741, § 2 (Exh. A), 2020)