Tuesday, December 02, 2008
Excreta Control and the VIP Latrine
I am reviewing the water and sanitation module this morning. One of our practice essay questions: "describe briefly how you would provide an excreta control programme in a refugee camp during the first few weeks of an emergency."
Let's see... well, I would definitely pull out my Sphere Project Humanitarian Response and Minimum Standards in Disaster Response handbook. The sphere project was started in 1997 by a group of humanitarian NGOs. They collaborated on a comprehensive disaster response handbook, which is free and downloadable from www.sphereproject.org. WHO also publishes a "Guide to the development of on-site sanitation." Of course there is always MSF's "Refugee Health: An Approach to Emergency Situations,"also free and downloadable.
These resources say that at the start of an emergency, you might only have time to build shallow trench latrines, which are essentially shallow pits that are covered by a thin layer of soil after defecation.
After a day or two, you will need to build something mroe permanent, such as a simple pit latrine, or better yet a Ventilated Improved Pit Latrine (VIP). A simple pit latrine is just a slab with a hole over a pit that is at least 2m deep. The bottom of the pit needs to be at least 1.5 meters above the water line under the soil, so that the excreta doesn't leak into the surface water supply. There should ideally be at least one latrine for each 20 people.
The ventilated improved pit latrine (VIP) has several clever features that make it a better option than the simple pit latrine. There is a superstructure over the latrine part that keeps the it darker inside than outside. There is also a ventilation pipe that exits the latrine roof. Odors from the latrine exit from the pipe. Flies and mosquitoes are also attracted to the light of the pipe, rather than the dark of the pit. You can put a trap at the top of the pipe to kill the insects as they fly towards the light. Image from Water Aid, an International Charity that helps poor people gain access to safe water, sanitation, and hygiene.