Slow Sand Filters

How Will the Intervention Help?

  • All locally available water is from surface sources such as streams or natural springs
  • All local surface water is contaminated with harmful micro-organisms
  • This contaminated water causes diarrhea, a significant cause of childhood deaths
  • A low cost method that can be make locally is needed to purify the water to be safe for drinking
  • A slow sand filter can remove 99.99% of all pathogens and can be made locally

Required Materials

  • 35-55 gallon plastic drum
  • PVC pipe, connectors, faucet, PVC glue
  • Small rocks/gravel of varying size
  • Clean fine sand
  • Flat rocks
  • Simple hand tools such as drill and hack saw blade

Building Process

  • Top of plastic barrel removed
  • PVC plumbing assembled and installed in barrel
  • Clean stones and gravel placed in bottom of barrel about 1/4-1/3 full
  • Clean sand placed on top of gravel to just below the faucet level
  • Flat rocks placed on top of sand to completely hide sand
  • The “slime layer” must form over a few weeks use before fully functional

Total Monetary Cost

  • $25-$45 for 55 gallon barrel, price varies locally
  • $10 for PVC components
  • Other materials gathered locally
  • Total cost = $35 - $55