Kathmandu, August 25:

A recent survey has found chlorine content in 47 per cent of piped water samples collected from 120 places of the Valley nil even as chlorination of drinking water is needed for its decontamination.

Initiated by NGO Forum for Urban Water and Sanitation (NGOFUWS) and tested by consumers themselves, 648 samples among the 1,385 tested in between June 9 and August 25 contained no Free Residual Chlorine (FRC) while 99 samples contained higher FRC than recommended.

The chlorine left free in the water after all reactions is called FRC. According to WHO, 0.2mg to 0.5mg FRC per litre of water is safe. Nepal Drinking Water Quality Standard 2006 also follows the WHO guideline.

Trace of FRC in water is the indicator that the water is free from germs. Low FRC (less than 0.2mg per litre) means incomplete destruction of germs. Samples from Dillibazaar Height, Ratopul, Naradevi, Anamnagar, Bhotebahal, Bhimsengola, Thapathali, Teku, Gongabu Ganeshthan, Godavari, Harisiddhi and Tyanglaphant were detected with no FRC.

“Absence of FRC is an indicator that the water might be contaminated with pathogens,” Said Praksha Amatya, executive director of NGOFUWS. There is an increase in the cases of water born diseases in the Valley during the last few months and lack of proper chlorination of water could be one of the reasons for it.

Chandra Lal Nakarmi, technical manager of Kathmandu Upatyaka Khanepani Limited, the sole distributor of drinking water in the Valley, said they treat the water in reservoirs at the rate of 1 to 2 mg per litre and the loss of chlorine at the household level could be due to the distance between the place of utilisation and reservoir and due to contamination of water pipes as the distribution network was old and sloppy. He said KUKL was planning to repair the distribution lines.

Amatya said FRC reports were being dispatched daily to the KUKL and other authorities concerned. “If the network cannot be repaired immediately, consumers can be made aware of the situation and ensure that they consumed properly treated water.”

He added chlorination at household level, boiling, filtration or SODIS treatment can be done to make the water safe for drinking.