Composting latrine maintenance.
The composting latrine at your school is a powerful means of turning a dangerous
waste product into a valuable commodity. Our human excreta contain bacteria,
viruses, worms and other parasites that can make us ill. The composting process is
designed to kill the organisms in our excreta that can make us ill. The most effective
means of creating a pathogen free compost requires active participation of the users
of the latrine. To create a compost that kills the dangerous pathogens that exist in
our waste is not a difficult job, but does require some effort and oversight. The goal
of our actions with the compost is to create a well aerated pile that can increase in
temperatures above 38° C. This paper serves to outline a best practice for the use of
the composting latrine, beginning with what the users should be doing every day,
and ending with the application of the compost.
Insert mechanics in terms of the exothermic reactions that generate heat in an
aerobic environment, which in turn kills parasites.
While the compost is accumulating in the base of the latrine additions must be made
to the pile. The additions are added to increase the amount of air available to the
pile, and reduce odor. After every use, or at the end of a school day, large pieces of
bulky leaf litter and organic matter should be added to the pile. When waste falls on
top of the leaf litter air is trapped beneath the leaf litter and puts voids in the pile
allowing for an aerobic environment in the pile. Fire ash may be added to the pile to
reduce odor however adding excessive ash increases the amount of time the pile
must sit before it has been fully composted. The composting will happen the fastest
if the pile is moist but not wet. If some urine gets onto the pile that is good, but
excessive wetting of the pile displaces the air in the pile and allows for more water
contaminated with human pathogens to enter the soil. So please keep the pile moist
but not wet.
While the pile is accumulating:
DO:
Add course or bulky leaf litter or organic material
Add small amounts of ash to control odor
Check the pile to make sure it has enough water
Do Not:
Add excess ash
Add excess water
Use the compost prematurely
Place cotton or other things down the hole of the latrine that will not
compost
When the pile is done accumulating, a trained person should open the compost
access door and carefully add more bulky leaf litter to the pile. If the pile appears
dry add a small amount of water. Once a layer of leaf litter has been added, place a
soil cap over the compost pile. It is important that the person performing these tasks
takes the proper safety measures and cleans with soap any tools that came in
contact with the premature compost. The leaf layer entrains air into the pile while
the soil cap reduces odor and keeps the pile moist. Let the pile sit while the other
side of the latrine fills up. This should take approximately one year, and the pile
should not be disturbed before a six-month time period.
Once the second pit is close to full the first compost pile which has now been sitting
beneath a soil cap for approximately a year may now be moved. Important: if the
compost is going to be used on a human food crop secondary composting is
required. The compost should have most human pathogens removed, however
some human parasites eggs may still exist in the compost and can make people sick.
To kill the parasite eggs secondary composting is required.
Secondary composting may be easily accomplished. The pile, which is now ready to
be moved, can be taken to an outdoor location where it will not be disturbed or
played in by children. Again the secondary compost should be restricted access. The
compost may be moved via wheelbarrow to the new site. More leaf litter should be
added to the pile along with small amounts of water if the pile appears dry. Good
composting practices should be used. The pile should be spread out so that it is of a
manageable size to be rotated. The goal is to introduce enough oxygen for the
microbes in the soil to increase the temperature high enough to kill all of the
parasites. If functioning well the pile should steam.