128 Building Toilets
2 pit compost toilet
The 2 pit compost toilet is like the simple compost toilet
for tree planting, but instead of planting a tree in the
pit, the compost is dug out and used in the garden or
fields. This toilet tends to be safer for groundwater than
traditional pit toilets because the waste is mixed with soil
in a shallow pit, allowed to dry out and kill germs, and
then removed.
To build a 2 pit compost toilet
Dig 2 pits 1 to 1 ½ m deep, 1 m wide,
and 30 cm apart. Add a lining or
ring beam to both pits (see page 122).
Place a platform and a simple shelter
30 cm
over one pit, and a concrete or wood
1 meter
1 meter
cover over the second pit. Use the first
pit until it is nearly full. A family of 6 will fill the pit in about 1 year.
1. When the first pit is almost full, fill it with 30 cm of soil and cover it with
a board or concrete slab. Move the platform and shelter to the second pit.
Use it until it is nearly full.
2. Leave the first pit alone. Or, after it has settled for 2 months, add more
soil and plant a seasonal vegetable like tomatoes right in the pit. Because
the waste in the pit is still being processed, it is best to avoid crops that
grow under the ground, such as carrots and potatoes.
3. When the second pit is full, empty the first pit with a shovel.
Wear gloves, and wash hands after handling the fresh fertilizer.
4. Store the dry matter from the pit in open bags or buckets
for later use, or add it to a compost pile or garden.
(To know when the contents are ready, see page 133.)
Move the platform and shelter back to the first pit, while
the contents of the second pit settle. And so on…
To maintain a 2 pit compost toilet
• Keep a bucket of soil mixed with
dry plant matter in the shelter.
After each use, throw a handful
in the pit.
• When the contents of the pit
get too high, stir it down with
a stick.
• Sweep and wash the platform
often. Be careful not to get
much water in the pit.
After 1 year, the contents of the 2 pit
compost toilet should be safe to mix into
garden soil as fertilizer. But it is still best to
wear gloves and shoes when handling it.
A Community Guide to Environmental Health 2012