For a full-service restaurant, Maricopa County plan review wants hand sinks within about 25 feet of every workstation, a three-compartment sink drained through a 1-inch air gap, a separate prep sink, a mop sink within 300 feet, mixing faucets, a 50-gallon water heater (75 with a dishwasher), and backflow protection.
The plumbing checklist
- Hand sinks centrally located, visible and directly accessible, approximately 25 feet from all food and beverage workstations, including every bar. Metal splashguards go between the hand sink and food, drink or utensil areas within 24 inches. Details in where a restaurant hand sink must go.
- Three-compartment sink, NSF approved, with its drain line indirectly plumbed with a minimum 1-inch air gap where permissible. A commercial dishwasher does not replace it. If you have a dishwasher you still need the three-compartment sink.
- Separate food prep and rinse sink, stainless, NSF, indirectly plumbed with a minimum 1-inch air gap, for defrosting and rinsing produce.
- Mop or service sink within 300 feet. See does a restaurant need a mop sink.
- Mixing faucets or valves on all sinks, including mop sinks, and hot or tempered water (100 to 110 degrees F) at every sink.
- Water heater minimum 50 gallons with a 100 percent recovery rate, and 75 gallons with a mechanical dishwasher. Tankless units can be approved but need prior review.
- Backflow protection on every fixture and piece of equipment connected to water, by approved device or air gap (ice machines are typically exempt). Carbonated drink systems need an approved testable reduced-pressure backflow preventer, and the county allows ASSE 1022 units but not ASSE 1032.
- Garbage disposals are not permitted on food prep or one, two or three-compartment sinks. They may be allowed on a separately plumbed pre-rinse or scraping sink or a dedicated vegetable waste grinder.
- Restrooms within 300 feet in a covered mall or 500 feet elsewhere. The county leaves fixture counts to the local jurisdiction, typically IPC Table 403.1.
What the county guide does not cover
Grease interceptors. The county guide is health-side. Your city's building department and pretreatment program decide whether you need a trap or an interceptor, its size, and what fixtures drain to it. Tempe, for example, requires an interceptor when a commercial dishwasher is present, and Scottsdale's code lists mop sinks and pre-rinse sinks among the fixtures that drain to it. See what size grease interceptor a restaurant needs.
Gas piping. The county guide does not mention gas at all. The city's fuel gas code and the fire code cover the cooking line's gas, as our page on whether a restaurant needs a gas leak inspection explains.
Timing
Plumbing rough-in is far cheaper to get right on paper than to move after the slab is poured. Bring the plumbing plan, fixture schedule and menu to plan review together. For how the inspection side works afterward, read restaurant plumbing health inspection requirements. HQ gives free estimates on restaurant plumbing scopes, with the price set up front before work starts.