Wastewater tank

A wastewater tank, or gray water tank, holds the used water from a food truck's sinks and equipment until it can be emptied at an approved site. The FDA Food Code requires it to be 15 percent larger than the fresh water tank.

The Food Code also wants it sloped to a drain of at least 1 inch with a shut-off valve. Texas asks for it to be labeled "wastewater." Los Angeles County goes further than the 15 percent rule and requires 50 percent more than the tanks feeding the hand and dish sinks, plus capacity for ice melt and product water.

Empty it at the commissary or another approved place, never on the ground. Size it alongside the fresh water tank and place both on the plan in the layout maker.