42 Water for Life
Filters for household and community use
Some filters can provide water that is almost as safe from germs as water that has been
boiled, treated by solar disinfection, or treated with chlorine.
Household slow sand filter
This is one of the safest, most effective, and
cheapest ways to filter water for a household.
This filter can treat at least 50 liters per day
— enough for a small family.
Equipment to make a slow sand filter:
• A watertight container such as a
200 liter barrel, or a large brick or
cement jar. Make sure the container
did not contain toxic materials
• A 20 millimeter hosepipe with many
small holes cut in the first
35 centimeters. This part with holes
will lay on the bottom of the barrel.
• A valve or tap
• A small amount of gravel
• Washed river sand
• Fine cloth
Concrete cover
Flat stone
Pour water
in here
Tap
Fine
cloth
Hosepipe
Sand
Gravel
200 liter barrel
How to MAKE A Household slow sand filter
1. Clean the container and disinfect it with bleaching powder.
2. Drill a hole 1/3 of the way down from the top of the container for the
tap. The hole should be sized for the fitting on the tap -- if the tap has a
12 millimeter fitting, the hole should be 12 millimeters wide.
3. Fit the tap to the hole and fix it in place with hard-setting putty. If a brick
container is used, the valve can be cemented within the wall.
4. Prepare the water collecting hosepipe. To do this, drill or punch many
small holes in the first 35 centimeters of the hosepipe, seal the end, and
form it into a ring on the bottom of the container with the holes facing
downward.
5. Connect the water collecting hosepipe to the tap. Seal the pipe fittings
with hose clamps or wire.
6. Place a layer of gravel 7 centimeters deep on the bottom of the barrel,
covering the water collecting pipe. Cover the gravel with fine cloth and
fill the barrel with clean river sand to about 10 centimeters below the
tap. Then cover the sand with a second fine cloth.
7. Make a cover for the container, with a hole in it to pour water through.
Place a flat rock or dish under the hole to prevent disturbing the sand
when water is poured in.
8. Flush the filter with water completely. Once the filter is cleaned, it is
ready for daily use.