Super Team

Rain Water Harvesting

How far the rain water is hygienic as a source of drinking water?

It is believed that the rain water is much more hygienic as a source of drinking water than ordinary well water. However some have cast doubt about the purity of rain water as it passes through the atmosphere, roof of the house and rain water harvesting tank before it reaches the final consumer.
The possibility of contamination with heavy metals when passing through the atmosphere is very much remote and the acidity too remains at tolerable level in any part of Sri Lanka. Also the number of diseases causing bacteria and viruses found in the atmosphere is to a negligible extent. Hence, there is hardly any threat of polluting the rain water when it is passing through the atmosphere.
Roofing materials such as tiles, asbestos, concrete, P.V.C., galvanize or tin sheets etc. contain no contaminant materials. However, tiny particles of certain paints and tar, if applied on roofing materials may washed away with runoff water. Also there can be impurities such as dust, leaves, droppings of birds and other animals on the roof top. All these impurities can be washed off with first flush system.
The rain water harvesting tanks are normally sealed structures and not even sun light can be entered into the tank. So that the Algae that normally found in rain water cannot thrive any longer causing deterioration of water quality.


Contact Us

Janathakshan Project

Practical Action Regional Office (Sri Lanka, India, Pakistan),

No 05, Lionel Edirisinghe Mawatha,

Colombo-5, Sri Lanka.


Tel : 94-11-2829412

Fax : 94-11-2856188

Email :