Slow Sand Filter

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
• $20-$30 for 55 gallon barrel, price varies locally
• $10 for PVC components
• Other materials gathered locally
• Total cost = $30 - $40

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