One of the items that can be overlooked by first-time food truck vendors is figuring out the size and type of water tanks needed to install in a concession trailer. Not only will you need fresh and gray water tanks to operate efficiently, but you’ll need these to meet the specific permitting requirements of the city and state you plan to operate. In this post, we outline all the things you need to take into consideration before installing water tanks inside your food truck. Take notes on this one because this post can take you a lot of time, money, and frustration in the event you discover you don’t have the right water tanks to pass a local health inspection.

Find Out What’s Required in Your Area

Before you start looking into specific types of water tanks, you’ll need to find out what you need to operate legally in your area as step one. The minimum size requirements for food trucks are regulated by the city or county you plan to operate. Before thinking about your personal water system needs, find out what the local requirement.
As an example Los Angeles County does an excellent job of outlining their requirements for a water system of a mobile food cart in their plan check guidelines PDF here. You read about the water tank requirement specifically by scrolling down to page 6 and looking for the Plumbing Layout System heading.
Below are important details you would need to take into account before getting a food truck or concession trailer built in our example area Los Angeles County:

  • Minimum 5-gallons of water for hand washing is required.
  • Minimum 15-gallons of water for ware washing.
  • Stainless steel and aluminum potable water tanks are not allowed in Los Angeles County.
  • Water tank cannot be installed inside of the enclosure (inside the mobile kitchen), above cooking equipment, or under plumbing lines.
  • The water tank must be fully insulated.
  • Waste water tanks must have 50% more capacity than potable water tanks.
  • Minimum of 3-gallons of water must be heated to 120 degrees F. Must be able to dispense heated water into one of the 3-compartment sinks within 10 seconds.

There are other requirements outlined in the plan check guidelines too, but at this point you get the gist. There are numerous considerations and details that must be considered when selecting a water tank for a food truck. One item to keep in mind is that some cities have much more detailed requirements than others. Where you plan to operate may not have a requirement as many requirements as listed here.
At M&R Specialty Trailers and Trucks, we’ve built hundreds of food trucks that operate throughout the United States and the world in our 15+ years in the industry. Part of our build process is to work with health departments to determine the laws and regulations to build a concession unit that meet the city or county requirements where you plan to operate. In short, we do all the work compiling the requirements in your area and submit build plans directly to health department so you can focus on other aspects of running your business.

What is a Potable Water System?

As you’re reading the build requirement documents from various counties for mobile food vendors, you may notice the phrase potable water system or simply potable water tank being referenced frequently inside these documents. Both refer to the tank that supplies the clean or fresh water for cooking needs. The explanation really is that simple, but the wording can cause confusion if you’re not familiar with the vernacular of these documents.
Related Reading: How to Legally Dispose of Gray Water for a Food Truck

Standard Water Tank Specs

Assuming you’re in the market for a water tank, we recommend going with a standard plastic tank to ensure approval from your health department. If you’re searching for these tanks online in specific sizes you can look up RV water tanks or recreational vehicle water tanks. The water tanks used in food trucks are the same as those installed in RVs, campers, and tiny houses. The only difference is you may have a specific size requirement based on your operational needs, permitting requirements, and vehicle requirements.
Two great online sources for high-quality water tanks is National Tank Outlet and Plastic-Mart. Both provide a long list of sizes that you can browse online. In most situations, you’ll be able to find a tank that meets your permitting needs and can be installed on your food truck or concession trailer.
Each of the example water tank specifications below are measured by length, width, and height. 
10 Gallon – 17″ x 14″ x 10″
16 Gallon – 24″ x 15″ x 10″
21 Gallon – 39″ x 16″ x 8″
30 Gallon – 34″ x 18″ x 12″
42 Gallon – 39″ x 18″ x 14″
65 Gallon – 37″ x 30″ x 15″
70 Gallon – 34″ x 23″ x 23″
The prices of these water tanks are determined mainly on size and shape of the equipment and are reasonable. For a 20 – 40 gallon tank you can expect to pay between $200 – $500. If you plan to operate something small like a hot dog stand or push cart, a small 7-gallon tank that you can purchase for under $100 might be all you need.
As a final point, while you don’t want to go too small with a water tank, make sure you don’t go too big either. For every gallon of water, you’ll be adding an extra 8.34 pounds of weight to your vehicle.  This water weight can add up fast as 5 gallons of water would be approximately 41.7 pounds. That’s a lot of weight sloshing around for smaller concession units, specifically. While there are always exceptions in custom manufacturing, for this reason we do not recommend installing 150 gallon and higher water tanks on mobile food units. Many food trucks operate just fine with nothing more than a 30-gallon fresh water tank installed.