What are the plumbing requirements for a restaurant health inspection?

The first question is whether the kitchen has an adequate, safe water supply under pressure. FDA Food Code section 5-103 requires enough water to meet the operation's peak demand. A salad station, a dish line, and three handwashing sinks all running at lunch rush cannot starve each other.

Handwashing sinks must be accessible, dedicated to handwashing and supplied for proper use. The locally adopted 2017 Food Code requires a sink equipped to provide at least 100°F through a mixing valve or combination faucet. The county's current guide calls for 100°F to 110°F at sinks and hand sinks centrally located, visible and directly accessible, approximately 25 feet from food and beverage workstations, including bars. The lower 85°F minimum in FDA 2022 does not replace Maricopa County's adopted requirements.

Inspectors confirm sinks are designed only for handwashing and that employees are not washing hands in prep or warewashing sinks. A handwashing sink that is hard to reach is treated the same as one that does not exist. The water supply itself must be from an approved source, and any private well or hauled water has to meet the same safety bar as a municipal connection before food handling can begin.

A dish-station fixture choice is separate from handwashing: the commercial pre-rinse spray-valve guide compares the task, performance documentation and connection questions.

A cross-connection is any point where the potable water supply could be pulled back into a contaminated source. The Food Code prohibits these under section 5-202.13, which calls for an air gap or an approved backflow prevention device on water supply lines.

The most reliable protection is a physical air gap: an unobstructed vertical space between the water outlet and the flood rim of whatever it fills. Where a gap is not possible, a tested backflow assembly stands in. Inspectors look at supply lines feeding equipment like dish machines, carbonators, and hose connections, plus the vacuum breaker on every threaded hose bibb. A submerged fill hose in a mop bucket or a steam kettle is a classic write-up.

Backflow assemblies in Arizona must be tested at least annually by a certified tester. For the testing rules and recordkeeping, see our guide on commercial-backflow-testing-requirements-arizona.

Food equipment cannot drain straight into the sewer. The Food Code, section 5-402.11, and ICC International Plumbing Code Chapter 8 both require an indirect waste connection for equipment where food, ice, or wash water is present. The drain line discharges into an open receptor, usually a floor sink, instead of being hard-piped to the sewer.

This is where the air gap returns. Maricopa County requires food equipment to be plumbed to floor sinks with a minimum 1-inch air gap. The IPC, in section 802.3, sets the air gap at no less than twice the effective opening of the indirect waste pipe. The visible vertical space between the drain line and the floor sink rim is what keeps sewage from siphoning back into a sink, steam table, ice machine, or dishwasher.

The Food Code is direct about why ice gets this protection. It states that a "food-handling sink, a warewashing machine, or an ice bin shall be discharged through an indirect waste pipe by means of an air gap." If an inspector sees a drain line jammed into a floor sink or tied directly to the sewer, expect a violation.

Floor sinks, floor drains, and mop sinks are not interchangeable. For the difference and which one each fixture needs, see floor-sink-vs-floor-drain-vs-mop-sink.

Three more items round out the inspection.

A grease interceptor must be present, correctly sized, and maintained. Fats, oils, and grease cool inside the line, harden, and choke the pipe. The EPA's 2004 Report to Congress found grease was the single largest identified cause of sewer blockages, tied to 47% of reported blockages, and noted that "nearly three-quarters" of sanitary sewer overflows in the arid Southwest were caused by blockages. That makes a working interceptor a Phoenix priority, not a formality. The common service standard is the 25% rule: clean it when fats, oils, grease, and solids reach 25% of capacity, often with a 30 to 90 day minimum interval. For pumping schedules, see how-often-pump-grease-trap.

A mop or service sink is required so floors and mop water are cleaned and dumped away from food sinks and handwashing sinks. Using a handwashing sink or a prep sink for mop water is a violation, and inspectors note whether the mop sink has its own supply with a backflow-protected hose connection.

Sewage must be conveyed through an approved system, either a public sewer or a permitted on-site system, under Food Code section 5-403. The line has to carry waste away with no backups into the building.

Finally, all of this only counts if it stays in good repair. Section 5-205.15 requires plumbing be maintained in good repair and operated according to law. A leaking faucet, a dripping trap, or a backflow device past its test date can each draw a citation even when the original install was correct.

Most plumbing write-ups in restaurant inspections repeat a short list. Walking the kitchen against it before the inspector arrives catches the obvious ones. Gas piping is not on the health inspector's list; our page on whether a restaurant needs a gas leak inspection explains who does check it.

• Blocked or cluttered handwashing sinks. Keep them clear, stocked with soap and towels, and confirm hot water reaches the required temperature (plan for 100°F to satisfy Maricopa).
• Missing or undersized air gaps. Check that every floor sink shows daylight between the drain line and the rim, at least 1 inch, and that no equipment drain is hard-piped to the sewer.
• Hose left submerged. Pull washdown hoses and mop-bucket fillers out of any standing water and verify hose-bibb vacuum breakers are in place.
• Grease interceptor overdue. Keep the interceptor below the 25% mark and keep the pump-out and manifest records on site; inspectors and the local sewer authority both ask for them.
• Backflow test lapsed. Confirm each assembly has a current annual test tag and that results were filed with the jurisdiction.
• Leaks and disrepair. Fix dripping faucets, sweating traps, slow floor drains, and loose fittings before they become a citation.

To prepare, assign one manager to run this list weekly and keep a binder with the grease interceptor service log, the latest backflow test reports, and the equipment drain layout. Confirm the water heater keeps up with peak demand so handwashing and warewashing sinks never run cold mid-shift. If you are remodeling or adding equipment, route every new food, ice, or wash-water drain to a floor sink with the proper air gap from the start, because retrofitting an indirect waste line after the fact is far more disruptive than building it in.

A health inspection rewards a kitchen that treats plumbing as part of food safety rather than an afterthought. Safe water in, dirty water out, and a visible gap between the two is the standard the FDA Food Code and Maricopa County are both measuring against.

Converting a space into a restaurant adds plan review on top of the health inspection. See retail to restaurant plumbing in Phoenix and how many fixtures a restaurant needs.

For the county's plan review checklist, see what plumbing Maricopa County checks in restaurant plans. Sink-specific rules are in where a restaurant hand sink must go and whether a restaurant needs a mop sink.

For the temperature numbers inspectors look for, see what temperature hot water must be in a commercial kitchen, and for dish machines see whether a restaurant needs a booster heater.

The city's separate grease inspection is covered in what a city inspector checks at a grease trap.

Inspectors also look at how an ice machine drains; see how to drain a commercial ice machine legally.

Running a mobile unit instead? See where a food truck dumps grease and gray water.

If a drain backs up during service, what the Food Code requires when a drain is cleaned or sewage backs up covers when a restaurant has to stop operating.