Your water system is one of the main things health inspectors look at. If you get the tanks, sinks, and heater right the first time, you avoid expensive rework and delays.

Core Components of a Concession Trailer Plumbing System

Most health departments expect to see all of the following in a typical food trailer:

Freshwater tank – Often in the 20–30 gallon range.
Greywater tank – At least 15% larger than the fresh tank.
Three-compartment sink – For wash, rinse, and sanitize.
Handwash sink – Separate from the three-compartment sink.
Water pump and accumulator – To provide steady pressure.
Electric water heater – Sized to provide consistent hot water during service.

Tank Placement and Layout

Freshwater tanks are commonly installed inside the trailer, protected from road debris and freezing temperatures. Greywater tanks can be mounted under the trailer as long as they are properly supported, enclosed where required, and accessible for cleaning and draining.

Plan your tank placement with weight balance in mind. A full water system can add a couple hundred pounds to your trailer, so you don’t want it all concentrated at the extreme front or rear.

Using PEX for Supply Lines

PEX tubing has become the standard in many trailer builds because it’s flexible, durable, and easy to work with in tight spaces:

Use red PEX for hot lines and blue PEX for cold lines.
Crimp rings and brass fittings make secure, permanent connections.
Support the lines with clamps so they don’t rub or rattle as you travel.

Drain Lines and Greywater

Drains are usually handled with PVC and standard sink traps. Make sure:

Each sink has a proper trap to prevent odors from coming back up.
The lines slope consistently toward the greywater tank.
You include a vent where required so the system drains smoothly.

The outlet on the grey tank should be easy to reach so you can hook up a hose and drain at approved dump locations.

Hot Water Requirements

Most inspectors will test your hot water at the sink. They generally want to see at least 110°F at the handwash and three-compartment sinks. Choose a water heater sized to handle your sink count and your typical usage, not just the smallest unit you can find.

Build With Inspection in Mind

Take clear pictures as you build, especially before you close up walls or cabinets around plumbing lines. Keep manuals for your pump and heater on hand. A thoughtful layout with accessible shutoff valves, visible lines where needed, and proper traps and vents will make your inspection smoother and your daily operation easier.