So far, 16 pond filter systems (PFS) and about 120 Rainwater systems (RWS) have been installed in Matlab.

Because of the arsenic-poisoned tube wells all over the country, Bangladesh has to go back to using surface water, mainly of ponds and rivers. But this water is unsafe for drinking if not boiled.

"Simple filtersystems can solve the problem," explained Md Jakariya of BRAC, who joined the two-day field trip on Wednesday and Thursday. He is responsible for implementation of such projects in Matlab.

"We would need waterpipe systems in Bangladesh, but they are too costly to realise in the short run," Md. Yunus is aware. Therefore, the ICDDR,B would recommend installation of rainwater- and pondfiltersystems as temporary solutions, Md Yunus adds.

The PSF is a cement unit, which serve a whole community, and is composed of different chambers with filters. The filters are made out of sand and brick chips, eating the bacteria.

In order to construct a PSF, a pond owner has to cooperate, putting his or her pond at disposition for the benefit of the whole community.

Another system installed in Matlab is household-based rainwatersystem. Rainwater is collected, after being filtered, during the rainy season in a 3200 liter cement container. The volume of water will serve a family for about 7 month if not wasted. Total installation of a contained costs about Tk 9000.

The community or the household has to pay 20 per cent of the construction costs. "They have the choice between cash or kind", explained Md Jakariya. One day of labor is worth about Tk 150.