(Xinhua)
Updated: 2007-12-22 14:50

Kathmandu -- Drinking water in the metropolitan, including Nepali capital Kathmandu Valley, has been found to be contaminated, The Himalayan Times reported on Saturday.

According to the daily, two separate studies on the quality of drinking water in these areas revealed that almost 90 percent of the total drinking water samples tested were found crossing the World Health Organization (WHO) guidelines in terms of the presence of coliform-intestinal bacteria.

Anup Muni Bajracharya of the Central Department of Microbiology (CDM) and a team from the Nepal Academy of Science and Technology (NAST) tested 114 water samples from stone spouts, taps and tube wells.

Bacteriological analysis revealed the presence of coliform in 90.35 percent of the samples -- 97 percent in tube well water, 73 percent in tap water and 100 percent in water from stone spouts.

In another study, conducted by Tista Prasai of NAST, Binod Lekhak and Dev Raj Joshi of CDM and Madhav Prasad Baral of the National School of Sciences, 132 water samples randomly collected from tube wells, wells, taps and stone spouts were tested.

It revealed that 92.4 percent of the samples crossed the WHO guideline value for drinking water regarding coliform count.

During the study, 238 isolates of enteric bacteria, which cause various health related problems, were identified including escherichia coli, enterobacter spp, citrobacter spp, salmonella typhi, proteus vulgaris and vibrio cholera.

Tista said the detection of the pathogenic enteric bacteria in different sources of drinking water reveals the possibility of water borne epidemics in the valley.

During the period between June 29 to July 19 this year, 1,753 water borne disease cases were reported in the valley according to the data provided by the Epidemiology and Diseases Control Division.

Bacteriological pollution could either be due to the failure to disinfect water at treatment plants or inflow of sewage through cross connection and leakage points, said Prakash Amatya, executive director of Urban Water and Sanitation.

Amatya said contaminated water could cause cholera, diarrhea, jaundice, food poisoning and typhoid. Therefore, drinking water should be chlorinated, boiled, or bio-sand filtered.