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Slow Sand Filter for Safe Drinking Water
cheap, local construction, little maintenance

Himcon, Uttarakhand South-West


Overview photo series and articles about constructive work


 This Slow Sand Filter is a construction of bricks and cement.

In the mountains the water of the springs is often polluted because of the agriculture in the neighbourhood and people who defecate. Moreover people take a bath, wash their cattle, cloths and utensils near the spring. In the end there are many water born diseases. For safe drinking water you need bottles, a centralised public water system, or a complicated and vulnerable machine what makes use of chemicals. All these three solutions are expensive and out of reach of the poor.

The Slow Sand Filter, designed by the University of Nagpur is a big box. It is constructed for example of stones or bricks and cement by a local mason. He doesn't need any special equipment or instruments. Because the box is build of local available material, the construction is cheap.


 Construction sketch.

In the box there are layers of bigger and smaller stones and grains of sand. On the top of the water floats a layer of algae, plankton and bacteria which bring oxygen in the water and break down organic matter. Including bacteria and viruses of faecal origin. At the stones and the grains of sand will grow a layer of organic material where the good bacteria live which eat the bad ones. No chemicals are needed and there is almost no maintenance.

The water what leaves the filter looks clear and has lost more than 99 per cent of the dangerous bacteria and viruses.


Contact: Rakesh Bahuguna
Himcon Milan Kendra
Sabli 249 199
Theri-Garhwal District - INDIA
rakeshbahuguna123 rediffmail.com
himconindia gmail.com


 On the top of the water floats a layer of algae, plankton and bacteria which bring oxygen in the water and break down organic matter. Including bacteria and viruses of faecal origin.


 Outlet of the purified water. From here the water flows to …


 … a concrete water tank of several thousands liters. People from the hamlet can take their share.


 Informing an activist from another village to spread the idea.



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photos ponds to collect rain water and check dams to prevent erosion
Go to: overview photo series and articles constructive work


Photos: Himcon, Uttarakhand and Peasant Autonomy - Creative Commons