Death rate of infant in Bangladesh is higher among developing countries. It is said that children die from diarrhca and other water-related diseases. Then authors investigated the water quality in 116 ponds and a few of reivers in 2002 where people daily use water for washing foodstuffs, eating utensils, clothes and bathing. The followings are obtained. 1) Pond water is contaminated with organic matter, coliform group colonies and unsuitable for daily use. 2) As surgace water and rainwater are safer than groud water, it is expected to set up tanks storing rainwater, and to develop the apparatus purifying the contaminated surface water
