4th International Conference on Rain Water Cistern Systems
Manila , Philipines - August, 1989

Paper E.5

Valuation Of Rainwater Quality: Heavy Metals And Pathogens

Wanpen Wirojanagud Pinthita Mungarndee band Patcharee Hovicitr
Khon Kaen University, Thailand

Abstract

Stored rainwater will be a potentially safe and economic drinking water supply if it is free from any contaminants. This study proposed to determine the bacteriological and chemical quality of stored rainwater. The rainwater samples were collected from collection systems, outdoor and in-house storage containers. Information on sanitary practices which appeared to affect the quality of stored rainwater was also investigated.

The study have shown that all of those sampling points were bacteriologically contaminated. Pathogenic contamination was found in a few samples collected from those sampling points. The pathogens identified were Salmonella gr. B and gr. C, Aromonas sp., and Vibrio parahaemolyticus. It was also found that the unhygienic sanitary practices of the villagers were a major factor in bacteriological contamination. The heavy metals analysed in this study were Cd, Cr, Pb, Cu, Fe, Mn, and Zn. Most of the heavy metal concentrations compared favourably with the WHO drinking water standard with two exceptions, Mn and Zn. These two heavy metals are considered to affect the aesthetic quality only, and therefore are not significant to health.

The findings from this study indicate that only health risks evolving from the consumption of stored. rainwater would be due to bacteriological contamination rather than from heavy metal contamination.

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