Which Scottsdale businesses and buildings need a backflow assembly?

Subsection (a) lists 54 items and activities. When one is present on a premises served by the city's water, the code presumes a hazard, and the listed assembly must sit at each service connection. The city does not have to prove contamination first.

Most listed uses call for a reduced pressure principle assembly (RP), the most protective of the three assembly types. The commercial and building entries owners run into most often:

• Restaurants, beauty shops, animal clinics and grooming shops, car washes, commercial laundries and food processing plants: RP.
• Medical and dental buildings, hospitals and mortuaries, and rest and convalescent homes: RP.
• Educational institutions, public and private: RP.
• Automotive repair with steam cleaners, acid cleaning or solvent facilities: RP.
• Cooling towers, boilers, chillers and other systems that use potable water for heating or cooling: RP.
• Post mix drink machines: RP.
• Buildings with plumbing higher than 34 feet above the service connection: RP.
• Buildings with house pumps or a potable water storage tank, with landscape fountains, ponds or baptismal tanks, or with sewage ejectors: RP.
• Commercial mini-warehouse or industrial buildings where one service supplies more than one tenant: RP.
• Shopping centers served by master meters, and master metered apartments, condos and townhouses with more than two units per meter: RP.
• Public swimming pools with self-levelers or automatic fillers: PVB or RP.
• Hydrant meters used for irrigation or construction water: RP or air gap.

Fire systems and irrigation have their own entries. Fire systems are explained on our fire sprinkler page, and sprinkler and irrigation assemblies follow subsection (a)(31).

• Service connection: the point where the city's water reaches the property. The assembly goes there, not at each fixture.
• RP: two check valves with a relief valve between them. It is the assembly for premises where a health hazard could push contaminated water back toward the main.
• Presumed hazard: the city treats the use as a hazard by definition, so an owner cannot argue that a particular restaurant is clean enough to skip the device.
• Most restrictive rule (49-62(b)): if a premises has two or more listed uses on one service, the most restrictive assembly wins, ranked air gap, then RP, then double check, then PVB.

It covers the owner or account holder of any premises on city water with a listed use, and the tenant and contractor who work there. It reaches some homes too: a house with a sewage ejector, a house pump or a storage tank falls under the same list, and so does a residence with a landscape pond. A hose bib is not a separate entry on this service-connection list, but fixture protection and the division's general hazard authority under Sec. 49-59 still apply.

A restaurant in a strip center. The restaurant is its own listed use, so its service connection needs an RP. If the center is on a master meter, the shopping center entry also calls for an RP at the master meter.

A medical office that adds a sewage ejector. The office already needs an RP as a medical building. The ejector is a second listed use and points to the same assembly, so one RP covers both.

The edge case: a use that is not on the list. Section 49-59 still lets Water Resources require protection wherever it decides your water system could contaminate the public supply. A shop with an unusual process can be told to install an assembly even though its business type is not in 49-62.

1. 1Walk the premises and list every use in your operation, then compare it with the 54 entries in Sec. 49-62(a).
2. 2If two listed uses share one service, plan on the most restrictive assembly.
3. 3Check whether an assembly already sits at your service connection. A plumbing contractor can tell you by the shut-off valves and test cocks on each end.
4. 4Read our installation permit page before you hire anyone, since each assembly needs its own permit.
5. 5Call Scottsdale Water Quality at 480-312-5668 with questions about your specific use, and keep the answer with your records.

• "Only industrial sites need one." Restaurants, beauty shops, schools and medical offices are all on the list.
• "A double check is cheaper, so we will use that." The code names the assembly per use. Scottsdale does not let an owner substitute a less protective type.
• "Our neighbor in Glendale has a double check on a storage tank." Glendale's list differs, and Scottsdale requires an RP for a building with a house pump or storage tank.

This page summarizes the code. The adopted text on Municode governs.