Notes from the Field: Composting Latrines Improve Water, Soil, and Health

by Claudia Menendez, International Program Coordinator


Here are some before and after photos of latrines in El Salvador. Our latrines are composting latrines with 2 compartments: one side is in use at one time. When it becomes full the other side is in use, giving the full side 6-9 months to decompose and dry up. When side B is full side A is cleaned out by shoveling the humanure or compost out of the compartment; the mixture is then used as soil or tilled into fields. And the cycle continues!

So far we are part way through the first cycle. We have asked the first 10 families of the pilot project to stop using Side A and allow it to decompose and dry so that we can make monitor the drying cycle and clean out process.

These latrines will have long-term improvement on community health by reducing  soil and groundwater contamination and related parasitic diseases.

How Does a Dry Composting Latrine Work?

The dry compost latrines consist of two chambers made of concrete cinder blocks with a toilet seat, including urine diverter, placed over each of the chambers.  After each use, stove ash, compost, and/or sawdust is added inside the chamber to reduce odors and keep the chamber dry. It also includes a vent to allow fresh air to circulate and further dry the solid matter.  After one chamber is filled it is left to dry during six to eight month periods while the second chamber is in use. The contents of the first chamber are then transformed into a rich fertilizer that can be used on surrounding crops or trees after a drying period under the sun and mixed with a 1:1 ratio of earth.  One dry composting latrine can serve families of more than six people for over 10 years with proper maintenance.