The Times  of India   06.09.2010

KMC to impose rules on groundwater use

KOLKATA: To combat the arsenic menace in the city, Kolkata Municipal Corporation (KMC) will soon require builders of housing projects to abide by guidelines it plans to prepare on sinking tubewells and drawing groundwater. KMC woke up to the arsenic menace after a survey revealed that most housing projects along EM Bypass, Lake Gardens, Golf Green, Behala, Jadavpur, Santoshpur, Garia, Bansdroni have come up with their developers flouting basic norms for installation of tubewells.

KMC's other measures against arsenic are to expedite construction of the Dhapa water treatment plant and augment capacities of Palta and Garden Reach water treatment plants. The Dhapa water treatment plant will cater to the demand for drinking water in east Kolkata, particularly by residents of existing and upcoming apartment buildings along Eastern Metropolitan Bypass.

The survey by KMC's water supply department served as an eye-opener, especially because residents of the areas mentioned are dependent on groundwater. "We need to ensure that tubewells are sunk after digging at least 300 feet deep. Even then, a filtration plant must be installed as a double-check on the quality of groundwater drawn. From now on, we will send our staff to collect samples of water when a big-diameter tubewell is sunk. A public analyst will test the sample. Only if the sample meets the desired standard will we allow the tubewell to be used," a senior official of the KMC water supply department said.

In fact, a team of scientists has found arsenic beyond permissible levels in a tubewell at Lake Gardens. "More than 300 milligrams of arsenic was found in a litre of water tested from the tubewell in Lake Gardens while permissible limit under WHO guidelines is 0.02 milligram/litre. We have set our permissible standard at 0.05 milligram/litre," an official of the state public health engineering department said.

KMC is concentrating on high-risk arsenic-prone zones like Behala, Lake Gardens, Garia, Bansdroni and parts of EM Bypass. Besides, the KMC water supply department has collected samples from areas where residents heavily depend on groundwater. "The samples are being tested at the KMC laboratory. Action, if required, will depend on the results," a KMC water supply department official said. KMC officials have also sought West Bengal Pollution Control Board's help in testing samples as PCB has a modern laboratory for testing arsenic.

However, KMC water supply department officials claimed that arsenic content in groundwater is within permissible limits in most parts of the city. "We have ordered closure of a big-diar tubewell inside Victoria Memorial and, instead, asked them to take a filtered water connection. Earlier, we had closed a tubewell at Behala. However, arsenic content in most areas where people depend on groundwater was found within permissible limits," a KMC official said.