Clean water is a vital necessity to the developing world – a purified source of water that meets international safety standards can ward off many contamination-related diseases. A test project by Stanford University, US, using an automatic chlorine dispenser in Dhaka, Bangladesh, proved that such a system ensures clean water supply and even reduces the impact of childhood diarrhea.

The simple tap device uses a stack of chlorine tablets that gradually dissolves and decontaminates the water is it flows down to a group tank by a standpipe. The innovative system uses no electricity and is entirely passive in function. Moreover, the people using it don’t need to do it themselves at home, a troublesome process which usually results in heavily-chlorinated – and bad-tasting – water.

Stanford’s researchers first polled people of two rural communities in the slums of Dhaka on how much chlorine could be added to the water before it tasted bad.The next step was to let the communities get used to the taste of chlorinated water and then upping to dosage until the taste was acceptable.

Out of 1,000 children, the chlorinated water drinkers had 23% lower rates of diarrhea than those of the control group, who drank water treated with vitamin C. The results also implied that the final chlorine dosage would be four times more likely to kill diarrhea-causing E. coli bacteria.

While water systems in much of the West has been purified and treated by various means, primitive systems are still found in cities in many developing countries which may carry less than desirable bacteria. Stanford’s practical water system would therefore provide nearly a billion people with clean, drinkable water. The technology is currently under development so that it can be installed on any tap.