Kagando Stove

Multi-Saver Stove, Uganda, 2008.

Africadev - Self Help Developments for Africa



Why:  Clean water is so essential to healthy living                                           (Top of page)

Clean water is so essential to healthy living.  And there is a surprising amount that can be done to improve your supply of clean water.  Some of the techniques are free, or cost very little.

Protection of supply:               (Top of page)

Whatever your water source - work hard to keep it clean.

Keeping animals out of and away from your water supply may be one simple improvement - build a fence or grow a thorny hedge around the place you get water from.  Both animal and human faeces in water can cause diarrhoea and other illnesses.

Keep out of the drinking water yourself.  Do not allow washing in the water supply.

If your water comes from a spring, where the water comes out from underground, try to collect the water as close as possible to the spring.  Ideally build a protective wall around the spring - see spring protection below.

Try to channel the water through a pipe or trough, or pump it into your water bottle, rather than putting the bottle into the water  - the bottle is probably dirty, and you will stir up mud and silt if you dunk it in the water.

 Water Treatment:                    (Top of page)

There are several low cost methods that can be used to treat water and make it safer:

  • Boiling is the most effective way:  boiling water for just 1 minute is enough, or 60 C for 10 minutes.  (Disadvantages:  the cost of fuel, and time.  But fuel efficient stoves can help reduce the cost and trouble).
  • Chemical disinfection is also very effective, using iodine, bromine or chlorine.  Turbid water must be filtered first.  (Disadvantages:  costly and complicated, affects taste, variable effectiveness.)
  • Storage:  storing water for 2 days will kill or greatly reduce most harmful bacteria.  Containers must be covered to prevent algae growth, and insects and dust.  Zero cost, and very simple.
  • Solar disinfection:  see SODIS below.  Near zero cost, and very simple.
  • Straining: Filtration through cloth.   Can even reduce cholera by 50%.   Near zero cost, and very simple.
  • Filtration, through a slow sand filter. How to (Disadvantages:  Not cheap and not simple, needs cleaning periodically, not always effective, can even become a breeding ground for bacteria, not effective for 1st week after building or cleaning, so an alternative treatment is needed.)
  • Filtration through a rapid sand filter:
  • Filtration:
  • Life Straw:  filtration by drinking through a specially manufactured straw - helpful against guinea worm. (link)

Sources:  UN-WHO Manual on Food, Water and Family Health (0.8mb download);  Gravity Fed Water Supply & Treatment (2mb  download) Well-factsheet  Well-technical-brief-58  Well-technical-brief-59

Straining Water:                    (Top of page)

Straining water through a simple cloth filter can be effective - and it is simple and free.  It has been proven to reduce cholera by 50% (Colwell or 0.1mb download), and is helpful protection against guinea worm.  (Other links: Indian-Press BMJ Wikepedia)

  • This method was proven effective by using fine weave cotton material used for saris in Bangladesh.
  • Old, well washed material was found to be best - repeated washing has reduced the spaces within the weave.
  • Several thicknesses of material are best - maybe 4-8 layers, as this reduces the effective pore size.
  • Cotton and nylon were both effective.
  • The material should be clean, be washed to remove filtered material, and be kept dry to avoid growth of bacteria.
  • Some people will find it easiest to filter the water as they collect it, others when back home.
  • The material must be fine weave.  (How wonderful if someone could do more research! - to prove the effectiveness of different materials, and to design a simple useful home-made filter.)

Sodis:                                          (Top of page)

SODIS, the SOlar DISinfection of water, can kill many bacteria in water, making it safer to drink.  And all that is required is a clear plastic water bottle, heat from the sun, and about 6 hours.

SODIS can reduce the occurrence of diarrhoea by 20-50%

The following important points should be noted:

  • The bottles must be clear and undamaged. 
  • PET plastic bottles, or clear glass bottles with good lids can be used.  PVC bottles cannot be used.
  • The maximum bottle size is 3 litres.
  • The water should not be stored in other bottles after treatment, but should be used direct from the bottle, or from a glass.
  • It is not necessary to paint half of the bottle black, nor to shake the bottle, nor to use clear water - as was once thought.
  • The process does not remove pesticides, fertilisers or other chemicals.
  • The weather must be clear and sunny. 
 How to  How to    

The pictures below show the 4 simple stages to making your water safe to drink:

WHO report on SODIS (click here)

 Spring Protection:                    (Top of page)

Further content to follow!

 Water Filters:                    (Top of page)


Biosand filter Ceramic Filter Potters for Peace filter How to  

Other Links:                                          (Top of page)

Sources:  UN-WHO Manual on Food, Water and Family Health (0.8mb download);  Gravity Fed Water Supply & Treatment (2mb  download) Well-factsheet  Well-technical-brief-58  Well-technical-brief-59

CAWST - a good site with practical ideas simply explained.



253 BytesApologies:  this site is still under construction - further content to follow!