Everything You Need to Know About a Vault Toilet

A vault toilet is a non-flush waterless toilet system installed in remote locations that don’t have access to a municipal sewer system. A vault toilet is a type of pit toilet where human waste deposits underground.

Vault Toilet

You may have run into vaulted toilets at forest service campgrounds. Most park services use privacy vault toilets. These are single units and are for only one person to use at a time.

Most vault toilets have a filled hand sanitizer dispenser in the unit. Some have sinks with running water.

Vault Toilet Facts

Vault Toilet

Although often compared to an outhouse, a vault toilet is not movable. An outhouse is portable; after the hole fills up it’s moved to a new location.

Vault toilets are permanent structures, although portable vault toilets are becoming more prevalent. They require emptying on a regular basis by a professional waste management company.

Vault toilets are designed for unisex use, although there can be a urinal that drains into the same holding tank.

Double vault toilets have two waste tanks that hold more waste in high-traffic locations. You can find double vault toilets in busy areas.

How Does a Vault Toilet Work?

The vault toilet system deposits waste into a tank under the ground. This tank is a sealed container made of reinforced concrete. The tank collects human waste and toilet paper but cannot handle trash.

The tank is called the “vault” – it’s how vault toilets got their name.

A hole is cut into the floor in the building above the tank. A toilet riser sits above the hole, and a toilet seat sits on the riser.

A large vent pipe on the top of the roof releases the gasses that build up from the waste.

Vault toilets no longer in use are torn down, and a concrete slab seals the underground tank.

What are Vault Toilets Made From?

The material which makes the riser of vault toilets is cross-linked polyethylene plastic. Cross-linked polyethylene is a heavy-duty plastic and has many uses in construction and building materials.

plastic vault toilets are durable, hard to break and withstand temperature swings. They work well in most climates and can withstand heavy-duty use.

Plastic vaults are an excellent choice if you want to make a portable outhouse, but you will have to pour a new concrete tank every time you move the toilet and structure around.

You can also find vault toilets made of wooden frames. The frame constructs the riser, and a toilet seat sits on top.

How to Remove Waste from Vault Toilet

A vault toilet underground tank is between 1,000 to 10,000 gallons in size. This large amount of human waste is toxic to the environment. The vault holds the waste in the vault tank until a waste removal truck removes it.

Waste management trucks suck the waste out of the tank. Then, they transport the sewage to a water treatment facility.

The local municipal council handles waste removal from public vault toilets.

Companies specializing in waste removal, like a porta-potty business, service vault toilets built on private land.

Tips For Using a Vault Toilet

Tips For Using a Vault Toilet

Put toilet paper into the vault toilet and do not use it as a trash can. If there are no trash services available, the trash leaves with you. You will help with park maintenance by keeping the vault toilets free from plugs and keeping our public spots clean.

Be wary of doors that don’t lock when using vault toilets in public spots.

Do not throw wet wipes into the vault toilet unless marked as safe to flush.

The Forest Service has been using vault toilets for decades. They do a good job of keeping vault toilets clean and stocked. Park services use one-ply toilet paper and low-grade sanitizer so bring your own if you want better quality products.

Pit Toilets vs. Vault Toilets

Although pit toilets are similar to vault toilets, there are some notable differences.

A pit toilet, also known as a pit latrine, uses a hole in the ground as a vault toilet does. However, the waste from a vault toilet is deposited into a concrete tank, whereas the waste from a pit toilet is deposited into an unlined hole beneath the soil.

If your waste situation is minimal, then a pit toilet is better than a vaulted toilet. A single person or small family might dig a pit latrine for temporary use while building a proper bathroom facility.

Vault toilets can accommodate a large volume of waste, but it’s toxic to the environment and cannot accumulate in an open pit like waste from pit latrines.

The waste from a pit toilet will decompose into the earth over time and therefore does not need emptying. Because of this, it is difficult to keep flies away from pit latrines.

The lifespan of a pit toilet is about five years, as the hole fills with waste over time. After that, you can move your pit toilet to a new location. Make sure to fill the old pit with soil to protect the environment.

Pit toilets can be stinky as the waste begins to decompose. You can counteract a stinky pit toilet by adding lye to the waste. Proper ventilation also helps.

Pit toilets serve best as a temporary situation, whereas vault toilets are permanent with proper servicing and maintenance.

Do Vault Toilets Smell?

Vault Toilet

Most vault toilets move smells away from the building. Smells are removed through the vent pipe as hot air rises up and out.

However, hot air has a harder time escaping during cold and damp days. And that is when vault toilets begin to stink.

How to Reduce Odors From a Vault Toilet

An important aspect of maintaining a vault toilet is figuring out how to get it to stink less. Since a vault toilet does not utilize water, the concentrated human waste can get odorous to an extreme degree.

As the waste breaks down, gasses are released into the space, causing a concentration of hydrogen sulphide. Reduce odors by adding an organic filler that converts hydrogen sulphide into odorless nitrogen gas.

You can also sprinkle large amounts of activated carbon into the waste. Activated carbon traps gasses in the open spots of the carbon, which helps tamp down the odors.

You can also run long underground pipes at the top of the waste tank that moves the odor away from the building.

Pros and Cons of a Vault Toilet

Vault Toilet

If you are thinking about installing a vault toilet on your property, consider these pros and cons first.

Pros of using a vaulted toilet are:

  • Vault toilets are self-contained. You don’t have to worry about where you install your toilet as all the waste is contained and will not leak into groundwater.
  • It does not require running water. These are a great solution if you don’t have access to running water from a well or municipal source.
  • Less environmental pollution. Since there is no water in the waste, there is less volume of pollution. It also won’t contaminate the natural environment since the waste sits in an enclosed container.

cons of using a vault toilet:

  • Odors are inevitable. Although there are effective ways to manage the odor, you cannot eliminate bad smells all the way.
  • They are not moveable. You cannot move the vault underneath the toilet. If it begins to leak, you have to seal it off and rebuild another one.
  • Vault toilets require servicing. Cleaning chemicals must be used for sanitation, and waste must be removed.

A vault toilet isn’t always the best option for a water-free toilet.

Different Types of Non-Flush Toilets

A non-flush toilet is ideal for homesteading, camping, and for those who want to help the environment by using less water and making less waste.

Vault toilets may not be the best solution for you. Several types of non-flushing toilets could suit your situation better.

Bag Toilets

These are waterless toilets that use bags for securing waste. Your waste goes into the bag, you press a button, and then the air is sucked out of the bag. The filled bag moves to the bottom of the toilet, and another takes its place. This process is all done through automation.

The filled bags are thrown out once the roll of bags has been used.

Bag toilets never stink because there is no air exposure. However, the bags used in this type of toilet is not biodegradable. There are better solutions where waste can break down and not sit in a landfill.

Composting Toilet

Vault Toilet

Composting toilets are waterless toilets that use peat moss, pine shavings, or other organic materials that the waste deposits into.

The toilet has a chamber that spins, mixing the waste with the organic material. As a result, the waste begins to break down into compost that is usable in your garden.

Prefabricated composting toilets are expensive, costing an average of $1,500. But you can build one yourself out of lumber. However, a prefab composting toilet has a nice sleek design that is easy to maintain and blends in with modern bathrooms.



Porta potties are movable temporary toilets commonly found at festivals and big events. Although they use some water, porta-potties don’t flush and are efficient for a large amount of traffic.

Depending on usage, porta-potties need frequent emptying, from once a day to once a week. If emptied on a schedule, porta-potties don’t stink much as the companies pour a strong antibacterial liquid into the water.

You can use a porta-potty as a temporary solution while building on your property. You will need to hire a company to haul the toilet to you, empty it on a schedule, and then haul it away when you no longer need it anymore.

Frequently Asked Questions (FAQ)FAQ

How much does it cost to build a vault toilet?

Building a vault toilet is expensive. An excavator or a tractor digs the hole for the vault. The vault itself is concrete. Then a building is placed over the vaulted toilet. These expenses can add up to over $5,000 if you have to rent equipment.

How deep is a vault toilet?

The vault is placed about 5 feet deep under the ground, but some vaults are as shallow as 3 feet. However, the vault cannot be too deep, or the walls will cave in from the pressure of the surrounding dirt.

Where can I purchase a vault toilet?

Most concrete companies sell the vault toilet riser, and you can buy the seat with it. You may be able to find one at the big box hardware stores or order one online. Cheap vault toilet risers start at $150.

Do vault toilets have toilet paper?

Although park services do stock toilet paper, it runs out. Therefore, it is wise to bring your own toilet paper and hand sanitizer while visiting a forest service location.

Are vault toilets sanitary?

Vault toilets abide by ADA regulations and are sanitary as long as the vault receives proper maintenance and sanitization procedures on a regular basis.

Vault Toilet: Conclusion

Most local concrete companies will do the work if you are interested in installing a vault toilet on your property. They can at least build the holding tank, and you can construct the rest.

Vault toilets will smell more in cold climates as the odor will sit lower to the ground on cold days. These work better in warmer regions that don’t get humid.

Since you have to rely on a waste company to pump your holding tank, vault toilets are technically not off-grid. Make sure you have a waste disposal company nearby willing to come out to your property before you install one.