Clean Water for Developing Countries – Part 2.
In part 1 we discussed how to provide clean water, how to filter and purify water and the need to educate the people about microscopic sources of disease. Continuing this theme of improving health through simple life style changes, it is important to eliminate open defecation, use of raw sewage on crops and cross contamination of drinking water with biological contaminants. Wells that are covered against contamination and accessed by hand pump are important, but so is sanitation and hygiene.
Families should be taught to
- filter and boil drinking water, especially for their infants and young children;
- use soap and water to bathe children regularly and wash their clothes;
- insist on regular hand washing with soap and water;
- emphasize no more open defecation in fields or streams;
- build and maintain proper toilets
- dispose of human and animal wastes away from streams, preferably by burning or burying garbage and trash;
- make soap using wood ashes and animal fat in the time-honored saponification process (see below).
Soap and Water Washing
- Soap and water handwashing, bathing and laundry are important to prevent disease. Soap not only removes visible dirt, but it is an excellent disinfectant. Soap and water washing of vegetables can disinfect them before consumption, making the food supply safer even in areas where raw feces are used on crops.
- Soap can be bought if funds are available, or can be easily made by villagers from readily available materials. (see example below)
- Excess handmade soap can be sold or traded for other goods or saved for later use.
How to Make Soap from Ashes and Fat
- Collect fine wood ashes in a wood or plastic container with small holes at the bottom and gravel and straw to retain the ashes. Mount on supports leaving room for a collection container. (Hard wood ashes work best. Avoid evergreen tree wood.)
- CAUTION: collected lye solution can burn skin and eyes. Avoid direct contact and wash off any contacted solution with plenty of water.
- Collect lye from the ashes using a water slow leaching method (rain water works best).
- Collect fats or oils from cooking (any will do).
- Heat the lye solution and separately heat the fats/oil in half-filled pots.
- Add the hot oils to the liquid lye solution while stirring to mix.
- Since the lye concentration will be uncertain, exact measurements are not possible. Start with a one-to-one ratio of fats to lye solution and add more fats as needed until all of the lye is reacted.
- Stir constantly for at least 30 minutes or until the mixture starts to solidify.
- Pour into greased molds and let set until the next day.
- Cut into conveniently sized bars.
This can be a community project with contributors receiving a share of the product. It can also be the basis of a small business.
- Prevent human and animal waste from entering streams.
- End the practice of open defecation.
- Isolate animal pens away from streams by proper placement, preferably below the level of the stream or by low mud, brick or stone retaining walls around lots or at the stream.
- Designate a garbage dump away from the stream, which can be regularly burned.
- Collect animal wastes in a designated area so that they will be composted over time before use. “Green” manure can burn plants. Aging keeps this from happening. It also digests disease causing bacteria, viruses, worm eggs, etc. to make them safe.
Shoes to Protect from Parasites
Shoes for all, especially children, are needed to prevent parasitic worms from entering through their feet. With proper toilets and isolation of feces from streams or other water sources, the spread of parasitic worms can be reduced. However, tiny worm eggs drop to the ground from an infected person and can be picked up by bare feet. When wastes are applied to farm fields, bare feet can also pick them up there. In addition to ending application of raw sewage on fields, it is important to treat worm infections medically to end the cycle.
Sanitation and Hygiene
Flush toilets with septic tanks are ideal. They can be either shared or installed in each home if pumped in water is available. If electricity is not available for pumping and purification, other immediate solutions must be put in place to end open defecation. Preferably, individual toilets for single families would further limit the spread of disease. Without pumped in water, flush toilets with septic tanks can be built and used by pouring water from streams for flushing. Water used in washing and cooking can be re-used for this purpose.
Pit toilets can be built for sharing with other villagers in order to end open defecation. Toilets need to have a means to exclude flies, which carry diseases, such as a seat cover, and a screened stack pipe above the roof to carry away odor and flammable gases. Pit toilets need to be built above grade so that surface runoff can’t enter. They need to be regularly treated with insecticide, lime, or ashes to reduce fly infestation. Several types include a simple pit, twin pit with movable structure, offset pit (septic) with pour flush basin, pit with baffle and access door that allows older accumulated waste to be removed and used on fields. Waste is safe to use on fields after one year.
Toilets can be built for squat or with an enclosed sitting platform. Both need seat covers to keep flies from entering and laying eggs. The twin pit toilet allows the filled pit to compost, dehydrate and digest pathogens while the second pit is filling. When the second pit is nearly filled, the first pit can be emptied and safely used as compost on gardens if the contents have aged at least one year. The first pit can then be re-used while the second one is composting. A single pit toilet will need a second pit to be dug when it is nearly filled and the contents needs to be buried with soil from the new pit or sealed for composting. Note that in areas where soil may collapse into the pit, walls of mud bricks can be built to retain the soil.
This design can also be used with twin pits for easier composting. Water for flushing can be from any source including used wash water, aka greywater.
 Mother Earth News, “How to Make Hot-Process Soft Soap,” Dec 2016/Jan 2017.
 WHO Publication, Emergency Sanitation: Assessment and Programme Design