2003 Volume 31 Issue 2 Pages 87-91
The contamination of tap water by microorganisms was surveyed at Surabaya and Jakarta, Indonesia, and at Hat Yai, Thailand. Water samples were directly collected from house faucets and filtered through membranes. The membranes were examined for protozoan parasites by immunomagnetic separation. Coliform and Escherichia coli were examined at each sample collection site using commercially available kits. A total of 115 water samples were examined and 37 (32%) were positive for any of four microorganisms which were two species of protozoa (Giardia intestinalis and Cryptosporidium parvum) and two kinds of bacteria (coliform and Escherichia coli). G. intestinalis and C. parvum were found in 9% and 1% of total samples, respectively. Of those detected, coliform was the most common and was found in all three areas with a mean detection rate of 30% (15-52%). The water samples that were positive for any of the four types of microorganisms showed a tendency to have lower residual chlorine concentrations and higher turbidities compared with negative samples. It is important to supply safe water in order to maintain people's health because most of the people surveyed (4-88%) ordinarily drank tap water without treating it. Continued efforts are needed to maintain and improve drinking water quality. (193 words)
