New Filtration System – 2009

Background

The primary purpose of the Water-Survival Box is to provide a means of purifying water for those without access to clean water so as to protect them from water-borne diseases. The WSB is especially useful following natural or man-made disasters and can be delivered by air worldwide within days of the request for help.

Since its inception in 2006 a process of continual review has been adopted by the Trustees leading to improvements in the box, its contents, and the delivery systems. The aim being simply to provide the best, most cost-efficient, most effective and timely response for survivors of disaster worldwide.

During the past year we have been working towards extending the useful life of the WSB as the means of purifying water. Until now the box could deliver two litres of drinking water for each member of a family of four or five people for about four months – using chlorine tablets to neutralise 99% of harmful bacteria and a carbon filter that could process 1,100 litres of water.

The new Fileder Carbon Filter

Having examined a variety of alternatives we concluded that this American filter could significantly extend the WSB. The Fileder filter is vacuum packed with carbon granules and designed to be used under pressure so that the new system incorporates an in-line handpump. Water is drawn out of the Water-Survival Box reservoir by way of the handpump and then pushed out through the Fileder carbon filter into the clean-water container.

Field Trials

Through Dr Nigel Harris (University of Bath) and his involvement with Ugandaid it was possible to have a prototype of the new filtration kit field-trialled in a typical village location near Jinja in south-east Uganda. Although the villagers were not in a post-disaster situation they lacked access to clean water due to the pollution of a borehole on which they had previously been dependent.

The feedback from Uganda was entirely positive. By following simple instructions (see pictogram) the box produced high quality clean water and the filter was entirely effective in removing the chlorine taste.

Whereas the effective life of the original filter would deliver some 1,100 litres of clean water the Fileder filter will deliver at least 3,000 litres. The new filter can therefore extend the useful life of the box from 4 months to one year.

Outcomes

It was against this empirical evidence that the Trustees decided to introduce the new Fileder filter and handpump filtration kit whilst retaining the traditional chlorine tablets as the means of purifying contaminated water.3.

Given that the new filter will produce three times the volume of clean water before coming to the end of its useful life the new kit includes three times as many chlorine tablets as in the past.

The new filter and increased number of chlorine tablets has raised the cost of the box but bulk purchasing and other economies mean we can keep the overall cost of the standard Water-Survival Box at £150 in 2009.

Thus the Water-Survival Box now has a more reliable filtration system and can protect a family from water-borne disease for up to one year.

PICTOGRAM – TEXT IN ENGLISH, FRENCH AND SPANISH *