Hesperian Health Guides
Toilet Choices
HealthWiki > A Community Guide to Environmental Health > Chapter 7: Building Toilets > Toilet Choices
No kind of toilet is right for every community or household, so it is important to understand the benefits of each toilet. Toilets connected to sewer systems are complicated to build, so this book describes only toilets that use little or no water. (The activity “Choosing the right toilet” can help decide which toilet may be best for your community's needs.)
ContentsToilets that use little or no water |
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Simple compost toilet for tree planting Best in places where people wish to plant trees and can manage a movable toilet. |
Urine diverting dry toilet Best in places where people will use treated human waste as fertilizer, and where the groundwater is high or there is risk of flooding. |
2 pit compost toilet Best in places where people will use treated human waste as fertilizer. |
Pour flush toilet Best in places with deep groundwater and where people use water for anal washing. |
Ventilated improved pit (VIP) toilet Best in places with deep groundwater and no risk of flooding. |
Closed pit toilet Best in places with deep groundwater and no risk of flooding. |
Note: These drawings show toilets with no doors and no covers over the toilet hole, so you can see what they look like inside. All toilets should have doors, and toilet holes should be covered when not in use. Also, toilets should be made so that everyone in the community can use them.
Where to build a toilet
more than
20 meters from river more than 20 meters
from spring box more than 20 meters from well
|
A toilet should be at least 20 meters from water sources. |
When deciding where to build a toilet, make sure you will not pollute wells or groundwater. The risk of groundwater pollution depends on local conditions such as the type of soil, the amount of moisture in the area, and the depth of the groundwater. But some general rules can make sure conditions are safe.
The bottom of the pit (if it is a pit toilet) or the chamber (if it is a dry or compost toilet) should be at least 2 ½ meters above the groundwater. If you dig a pit for a toilet and the soil is very wet, or if the pit fills with water, this is a bad place to put a toilet. Keep in mind that water levels are much higher in the wet season than in the dry season. Do not build pit toilets on ground that gets flooded.
When there is a risk of groundwater pollution from pit toilets, consider building an above ground toilet (such as the urine diverting dry toilet).
Groundwater flows downhill. So, if there is no choice but to build a toilet in a place where there is a risk of groundwater pollution, place the toilet downhill from nearby wells.
Closed pit toilets
A closed pit toilet has a platform with a hole in it and a lid to cover the hole when it is not in use. The platform can be made of wood, concrete, or logs covered with earth. Concrete platforms keep water out and last many years. A closed pit toilet should also have a lining or concrete ring beam to prevent the platform or the pit itself from collapsing. (See “How to make a concrete toilet platform” and “How to make a concrete ring beam.”)
The ventilated improved pit (VIP) toilet uses a vent pipe to reduce smells and flies.
A problem with pit toilets is that once the pit is full, the toilet can no longer be used. To take advantage of the waste in full pits, plant a tree on the site. To do this, remove the platform, ring beam, and shelter, and cover the waste with 30 centimeters (2 handwidths) of soil mixed with dry plant matter. Allow several months for the waste to settle, fill it with more soil, and plant a tree.
Another option is to add soil frequently while the toilet is in use and let it sit for 2 years to allow the waste to decompose. Then dig it out, use the waste as fertilizer, and use the pit again. Always wash hands after handling and digging the soil around toilets.
To make a closed pit toilet
- Dig a hole less than 1 meter across and at least 2 meters deep.
- Line the top of the pit with stones, brick, concrete or other material that will support a platform and prevent the pit from collapsing. A concrete ring beam works well.
- Make a platform and a shelter to put over the pit. A concrete platform works best, but local materials like logs or bamboo and mud can work too. If you make a platform from logs, use wood that does not rot easily.
How to make a concrete toilet platform
A well made concrete platform will last many years. One 50 kilo bag of cement will make 4 platforms, or 2 platforms and 2 ring beams. You will also need reinforcing wires, bricks, and boards to form the mold, and wood cut to the shape of a keyhole to mold the hole. Platforms can be square or round.
1. Lay down a plastic sheet or used cement bags on flat ground. On top of this, make a mold of bricks or boards about 120 cm long, 90 cm wide and 6 cm deep. | 2. Place a wooden keyhole mold in the center, to shape the toilet hole. You can also use bricks to block out the hole, and shape the hole after you pour the concrete. |
3. Make a concrete mix of 1 part cement, 2 parts gravel, 3 parts sand, and enough water so that it is wet but holds together well. Pour the concrete into the mold until it is halfway to the top. | 4. Place reinforcing wires 3 mm thick on top of the wet concrete. Use 4 to 6 wires going in each direction. Make handles of wire 8 to 10 mm thick, and set them in the concrete near the corners. |
5. Pour the rest of the concrete, and level it with a block of wood. |
6. Remove the keyhole mold when the concrete begins to harden (after 3 hours). If you used a brick mold, remove the bricks and form the hole into a keyhole shape. Cover the slab with wet sacks, damp cloth or a plastic sheet overnight. Wet it several times a day to keep it damp for 7 days. Keeping it wet lets the concrete harden slowly and become strong. |
7. When the concrete has hardened, place the platform over the pit. To make the pit more secure, also use a ring beam. | 8. Make a cover for the hole out of concrete or wood. It can have a handle, or make it to be moved by foot to keep germs off the hands. |
Platform improvements
Because germs and worms can collect near the hole, foot rests will reduce the risk of health problems. If people prefer to sit, make a round hole and a concrete seat.
To make a mold for a seat, use 2 buckets of different sizes, one inside the other. There must be several inches between the sides of the inner bucket and the outer bucket. Weight the inner bucket with rocks so it stays on the bottom. Pour concrete into the space between buckets.
How to make a concrete ring beam
A ring beam is a square or round piece of cast concrete with an open center that supports the toilet platform and shelter, and keeps the pit walls from collapsing. The ring beam described here can be used along with the concrete platform for all pit toilets. The size of the ring beam you make depends on the width of the pit.
A mold for the ring beam |
Pouring the concrete |
Reinforcing wire |
- Lay down a plastic sheet or cement bags on level ground.
- Make a mold of bricks, wooden boards, or both. For a platform that is 120 cm by 90 cm, the ring beam will be 130 cm by 1 m on the outside, and 1 m by 70 cm on the inside.
- Make a concrete mix of 1 part cement, 2 parts gravel, 3 parts sand, and enough water so that it is wet but holds together well. Pour the concrete into the mold until it is halfway to the top.
- Place 2 pieces of reinforcing wire 3 mm thick on top of the wet concrete on each side of the ring beam. If you want, you can make handles of wire 8 to 10 mm thick, and set them in the concrete near the corners.
- Pour the rest of the concrete, and smooth it with a block of wood.
- Cover the concrete with wet cement sacks, wet cloth, or a plastic sheet, and leave it overnight. Wet it several times a day to keep it damp for 7 days.
- When the ring beam is solid, carry it to the site of the toilet. Level the ground, place the ring beam, and dig a pit inside of it. Pack soil around the outside of the ring beam to set it in place.
- Place the toilet platform on top, then build a shelter.
Ventilated improved pit toilets (VIP)
The VIP toilet is an enclosed pit toilet that reduces smells and flies.
How the VIP works
Wind blows across the top of the vent pipe and carries away smells. The shelter keeps the toilet dark so the flies in the pit will go toward the light at the top of the pipe, get trapped by a wire screen, and die.
To make the VIP toilet
- Dig the pit 2m deep and 1½ m wide. Line the top with bricks or a concrete ring beam sized to fit the pit (see “How to make a concrete ring beam”). If the shelter will be very heavy (brick, concrete, or heavy wood), line the whole pit, except the bottom. Leave gaps in the brickwork to let liquids out.
- Make a platform (see “How to make a concrete toilet platform”) 1½m by 1 m, with 2 holes in it. The second hole, near an edge of the platform, is for the vent pipe. Make the vent pipe hole no less than 11 cm wide.
- Build a shelter over the pit and platform.
- Fit a vent pipe at least 11 cm wide tightly into the smaller hole. Paint the vent pipe black to absorb heat and improve ventilation. Cover the top of the vent pipe with a mosquito screen (aluminum or stainless steel will last longest). Make the vent pipe rise at least 50 cm above the roof so the wind can pull out bad smells.
To use and maintain a VIP toilet
- Keep the hole covered when not in use.
- Keep the shelter dark inside.
- Keep the toilet clean and wash the platform often.
If the vent pipe gets blocked by spiderwebs, pour water down it.
VIP toilets can have these problems:
If the shelter is not dark enough, or if the hole is left uncovered, flies will not fly up into the pipe. And if the shelter has no roof, or if the screen breaks or comes off the vent pipe, there is little fly control.