The Hindu 06.11.2009
Close monitoring of chlorine content in drinking water
Special Correspondent
| Residual chlorine must be 2 mg or .2 ppm |
— Photo: S. Siva Saravanan 
Special drive: An official of the Coimbatore Corporation checking the chlorine level in drinking water in Coimbatore.
COIMBATORE: The Coimbatore Corporation has stepped up the monitoring of the chlorine content in drinking water in view of the North-East Monsoon.
Norms mandate 2 mg of chlorine in the tail-end areas of distribution, while the main service reservoirs (or overhead storage tanks) should have 5 mg.
“The residual chlorine in the tail-end areas must be 2 mg or .2 ppm (parts per million). We check the roadside taps or even those in houses to check whether the minimum chlorine quantity is available. This is done before the actual supply of water begins,” Assistant Engineer K. Karuppusamy explained during a chlorine monitoring exercise at the Ganapathy Main Service Reservoir recently.
Normally, the chlorine level was checked only at the main service reservoirs – one for the Siruvani scheme and the other for the Pilloor scheme. But, to prevent diseases such as diarrhoea because of water contamination during monsoon, extra efforts are taken to ensure there was no dilution of the chlorine content.
Apart from these reservoirs, the chlorine level was being monitored in more than 40 overhead tanks of both the schemes.
Both the Siruvani and Pilloor water schemes had a telemetry system that quickly pointed out any dip in the chlorine level.
Besides, 36 Sanitary Inspectors and five water supply engineers had been provided with chloroscope – an equipment to measure chlorination level.
In case of reduction in the level, the officials would inform the treatment plants of both the schemes. Even if the chlorine was mixed in water at the plants, it would take two to three hours for this water to reach the main service reservoirs. But, during this gap, chlorination would be done at the reservoirs, the official explained.
