A Type III cooking food truck in Maricopa County needs a pressurized hot and cold water system of at least 30 gallons, a hand sink, a three-compartment sink with at least 6-gallon basins, and a wastewater tank 15 percent larger than the fresh tank. Fill and dump at an approved commissary or as the Department approves.
What counts as a Type III food truck?
The county's Mobile Food Type III guidelines define it as "an enclosed vehicle-mounted food establishment that prepares, cooks, holds and serves food." That's the typical food truck or enclosed trailer with a grill, fryer or flat top.
The plumbing rules below come from Regulation 9 of Chapter 8, Section 3 of the county code, "Additional Requirements for Mobile Food Type III." Carts and trucks that only sell packaged food fall under other types with lighter rules.
What water system does the truck need?
A pressurized one, with hot water. Regulation 9 spells it out. "A potable water system under pressure, supplying hot and cold water, with a minimum capacity of 30 gallons, shall be permanently installed for utensil washing/sanitization and handwashing."
The guidelines list what the plan review looks for:
- Fresh water tank. The plans show "Fresh Water Tank Dimensions (30 gallons)" at minimum.
- Prep sink water. "If prep-sink is installed, 20 gallons of additional fresh water is required," the guidelines say.
- Hot water. The truck needs a "Water Heater or other approved hot water source" on board.
- Fill inlet. The "Fresh Water inlet no greater than ¾ inch" sits "at top or higher point" of the tank.
- Fill hose. Use an "NSF or FDA-approved water hose (food grade)" for filling.
The code adds that the inlet must have "a hose connection of a size or type that will prevent its use for any other service," and the guidelines say "All plumbing connections shall be different sizes" too. That keeps anyone from filling the fresh tank with the wastewater hose. The code also requires "An approved food grade potable water hose" kept "for the sole purpose of filling the fresh water tank" and nothing else.
### How often do the tanks get sanitized?
Regularly. Regulation 9 says "All water tanks, pumps and hoses shall be flushed and sanitized before being placed in service after construction, repair, modification, and periods of nonuse longer than 7 days" before use. It also says "Potable water tanks shall be flushed and sanitized monthly."
What sinks does the truck need?
Two, and a third if you wash produce on board.
A hand sink. Regulation 9 says "A 9x9x5" hand washing sink shall be permanently installed" in the truck. The guidelines add a "Combination mixing faucet of hot & cold water at the sink" as well.
A three-compartment sink. For washing and sanitizing utensils, the code requires:
- Flow: "A minimum flow rate of one-half (1/2) gallon per minute" at the faucet.
- Heat: "Water at a temperature of at least 38°c (100°f) shall be provided through a mixing faucet" to the sink.
- Size: "Each compartment shall have a capacity of 6 gallons" or more.
- Drain boards: "Two integral metal drain boards shall be permanently affixed that are the same depth as the 3-compartment sink" on the unit. The guidelines size them at "at least 144 square inches" each.
A prep sink, if you want one. The code allows "a prep-sink for the purpose of produce washing only," as long as "an additional 20 gallons of potable water is available for use" on the truck. Without it, the guidelines say produce "may not be washed in the unit unless an approved prep sink has been installed," so it has to arrive pre-washed.
For comparison, a fixed restaurant has its own sink rules. Our guides to restaurant hand sink placement in Maricopa County and Maricopa County restaurant plan review cover those.
An outdoor booth or short-term food setup is a different review: use the temporary-event water and wastewater plan rather than borrowing a truck's tank requirements.
What about the wastewater tank?
It has to be bigger than the fresh tank and drain completely. Regulation 9 says a sewage holding tank shall be:
- "Sized 15 percent larger in capacity than the water supply tank" on the truck.
- "Sloped to a drain that is 25 mm (1 inch) in inner diameter or greater, equipped with a shut-off valve" for dumping.
The guidelines repeat the details: a "Wastewater drain valve greater than 1 inch," a "Waste water tank drain at the lowest point of the tank," and a design where "Water is continuously evacuated by opening the valve." They also call for a "Quick-Disconnect design (sewer & potable water)."
So a truck with the minimum 30-gallon fresh tank needs at least a 34.5-gallon waste tank. Add a prep sink and 20 more gallons of fresh water, and the waste tank grows to match.
Where can a food truck fill up and dump?
Only at an approved commissary, or somewhere the county approves. Regulation 9 says trucks "shall not connect to water or wastewater systems except during servicing operations at a commissary or as approved by the Department." It also says "Wastewater holding tanks shall be emptied into an approved sewage disposal system."
The general rules in Regulation 5 add that trucks "shall report at least daily" to the commissary "for supplies, food storage, vehicle and equipment cleaning, waste disposal, and service operations." And "All wastewater and grease shall be disposed of in a sanitary manner."
That means no dumping gray water into a storm drain, a parking lot or a yard. Arizona's gray water rules don't help here either: our page on whether gray water is legal in Arizona explains that kitchen sink water is kept out of the gray water category entirely.
### What does the commissary need?
The commissary is a permitted food establishment with the plumbing to service trucks. Regulation 13 says it must "provide for the sanitary disposal of liquid waste; handling and disposal of garbage, grease, and rubbish originating from mobile food establishments; and facilities for filling the potable water holding tank." Commissaries with an outdoor servicing area also need "an adequate area (facilities) for washing and storage of the mobile food establishment."
The county's commissary agreement form adds one plumbing catch. If a truck with a three-compartment sink plans to use a commissary that isn't on the county's approved list, the operator "must obtain written approval from the local jurisdiction where the permitted fixed food establishment is located to obtain approval to discharge wastewater." That's usually the city's pretreatment program. Each truck also needs "a signed commissary agreement" at initial permitting and at renewal.
If you run a commissary, grease from truck waste lands in your interceptor. Our guides to what can go down a restaurant grease trap and how to size a grease interceptor cover the fixed side.
### What else does plan review ask for?
A custom-built truck, or one that hasn't had a Maricopa County permit in the last 3 years, goes through plan review. The guidelines list a "Side View Plumbing Schematic," a "Top View Layout/Equipment" drawing, and the tank and sink dimensions above. The county then sends "a stipulation approval letter" with any changes before scheduling an inspection.
Trucks already permitted under Arizona's state licensing rules follow a shorter path. The guidelines say "The initial permitting approval is conducted in the county where the commissary is located," and "No plan review/plan review fee/facility inspections are required for those units that have been approved in accordance with state licensing requirements." A commissary agreement "may still be required in Maricopa County."
Plan the plumbing before the build. Moving a tank or adding a prep sink after the truck is framed is harder than drawing it right the first time.
HQ Plumbing & Air works on the fixed side of mobile food across the Phoenix area: commissary kitchens, water fill connections, grease interceptors, floor sinks and sewer lines. We're licensed and insured, available 24/7, and every job starts with a free estimate and upfront pricing. See our commercial plumbing services and our guide to when a floor sink is required in a commercial kitchen.
Fill and empty the tanks at the approved servicing location, whether that is a commissary or another Department-approved arrangement.