Preventing Diarrheal Disease in Developing Countries:  Proven Household Water Treatment Options

The health consequences of inadequate water and sanitation services include an estimated 4 billion cases of diarrhea and 1.9 million deaths each year, mostly among young children in developing countries.  Diarrheal diseases lead to decreased food intake and nutrient absorption, malnutrition, reduced resistance to infection, and impaired physical growth and cognitive development.  Since 1996, a large body of work has been published that has examined the health impact of interventions to improve water quality at the point-of-use through household water treatment and safe storage (HWTS).  Five interventions – chlorination, solar disinfection, ceramic filtration, slow sand filtration, and PUR – have been proven to reduce diarrhea in users in developing countries and improve the microbiological quality of stored household water and are discussed below. The most appropriate HWTS option for a location depends on existing water and sanitation conditions, water quality, cultural acceptability, implementation feasibility, availability of HWTS technologies, and other local conditions.  For more information, contact safewater@cdc.gov. Photos courtesy: PSI, PFP, Hydraid, EAWAG, P&G.

Table of Contents

• Preventing Diarrheal Disease in Developing Countries:  Proven Household Water Treatment Options
  • Household Chlorination
  • Ceramic Filtration
  • Slow Sand Filtration
  • Solar Disinfection – SODIS
  • Flocculant / Disinfectant Powder - PUR Purifier of Water™
  • Resources
  • Related Pages

Household Chlorination

Household chlorination includes water treatment with chlorine solution at the point-of-use, storage of water in a safe container, and behavior change communication.  Users add one cap of solution to their storage container .  Diarrhea reduction is 22-84%.  Product cost is 0.01-0.05 US cents per liter treated.  Benefits are residual protection against recontamination, acceptability to users, ease-of-use, scalability, and low cost.  Drawbacks include potential user taste and odor objections, and lower protection against some organisms and in turbid water.  www.cdc.gov/safewater

Ceramic Filtration

Ceramic filters depend on mechanical processes to remove contaminants.  Users simply pour water through the filters.  Diarrhea reduction is 60-70% in commercially manufactured filters in conjunction with safe storage.  Product cost is 0.034-0.14 US cents per liter treated.  Benefits include user acceptability because of ease-of-use, long life if the filter remains unbroken, and potential for local production.  Drawbacks include unknown effectiveness against viruses, lack of residual protection that can lead to recontamination, the need for user education to keep the filter and receptacle clean, and slow flow rates.  www.pottersforepeace.org  

Slow Sand Filtration

The Slow Sand Filter (SSF) is a sand filter adapted for household use.  To use the SSF, users simply pour water into the SSF, and collect finished water out of the outlet pipe into a bucket.  Diarrhea reduction is 44-47%.  Product and program costs over a 10 year life span is 0.068 cents per liter treated in one NGO program.  Benefits include turbidity removal, high flow rate, ease of use, long-life, low maintenance requirements, and local production.  Drawbacks include unknown effectiveness against viruses, lack of residual protection that can lead to recontamination, the need for user education to keep the filter and storage container clean, and heavy weight.   http://www.cawst.org