THE BACTERIOLOGICAL QUALITY OF RAIN-JAR WATER IN RURAL NORTHEAST THAILAND

Rainjars are popular in northeast Thailand because of the time and effort saved in water collection resulting from their use. Bacteriological analysis showed rainjar water to be much purer than drinking water from alternative sources (P < 0.001). In rainwater samples from one village, Escherichia coli was absent in 60% of rainjars compared with 46% of other vessels used for storing drinking water in the home (P < 0.01). The use of a tap and the physical height of the jar served to protect the water by limiting water handling. Moreover, mosquito netting fitted to the top of the rainjar significantly improved its water quality (P < 0.05), probably by preventing the access of small lizards. It is suggested that any systematic attempt to improve the quality of rainjar water further, in order to achieve the WHO guidelines, would be both problematic and expensive whilst the expected health benefits remain negligible. The problems of using drinking water quality guidelines for discrete supplies and the role of water analysis are discussed.