A vault toilet is a toilet bowl used over a sealed tank in the ground. A bathroom building is placed over it. Because it is low-tech, a vault toilet is often used in parks and other rustic or simple settings.
Unlike a traditional toilet, it does not use water for flushing. Instead, it uses gravity to let wastes drop into the tank.
The typical vault toilet can store 500 to 1,000 pounds of urine and fecal waste.
When the tank is full, the vault toilet must be pumped out. The waste must then be taken to a government-approved waste treatment facility.
A vault toilet is prone to odor problems. Several products and systems are on the market to decrease this by either adding a fragrance or altering the bacteria activity to aid in the decomposition of the waste. Today's vault toilets are designed with proper ventilation, outdoor access to the pump-out process and other features that make them more user-friendly than older models.