The Times of India            12.12.2013

Desilting plans for Rankala take shape

KOLHAPUR: The Kolhapur Municipal Corporation (KMC) is preparing a plan for the internal treatment of the Rankala lake to remove the huge amount of accumulated sludge, estimated to fill as many as 70,000 to 1,00,000 dumpers, officials said.

The lake, which is a part of the National Lake Conservation Plan ( NLCP) initiated by the Union environment and forests ministry a decade ago, is yet to fully utilize its sanctioned amount of Rs 8.65 crore. Since the 16 works, including the major task of arresting sewage water discharge, are in the final stage, the KMC is mulling the next step to desilt the lake.

The KMC has drafted a couple of plans, including chemical treatment to neutralize the sludge as well as flushing it out by creating gates at the bottom of the lake. The civic body's experiments to remove the sludge manually had failed in the past. "We are yet to finalize the plan and have appointed a consultant for this phase of work. The structure of Rankala is like a dam; which overflows when its reaches the maximum storage capacity. Obviously, the sludge remains in the lake for years and it may keep on polluting the water," said R K Patil, environmental engineer of KMC.

KMC had laid a pipeline for Sarnaik Vasahat, Deshmukh hall, Shyam Society and Partala nullah, which were directly polluting Rankala for years. The work of pipeline of 2.8 km is almost complete, only a small section of 150 metres remains.

Patil said that they are looking at various options to remove the sludge to clean the lake. "We have Rs 1.88 crore kept aside for interior treatment of the lake. The sludge has to be removed else all efforts of arresting sewage water would go waste. It will take months to remove the sludge and require funds of Rs 30-35 crore," he said.

Environmentalists and experts have cautioned the KMC before taking further steps, saying the earlier steps to desilt the lake had failed. Eutrophication is a natural phenomenon and no manual efforts to remove sludge are possible in Rankala lake case, they said.

Eutrophication is a process by which a water body acquires high concentration of nutrients, especially phosphates and nitrates, through fertilizer run-off and sewage discharge. These typically promote excessive growth of algae.

"We have to work on alternatives. The previous efforts had failed since the volume of sludge was huge. If KMC is preparing such plans again, it has to work on the use of sludge first. I don't think a natural gate to desilt the lake exists," said Jeevan Bodake, architect and nature lover.

Jay Samant, a member of Wetland international, Asia, warned that the KMC should first concentrate on fully arresting the discharge of pollutants and then go for removing the sludge. "We have to understand the lake with wetland perspective. It is not a water-tank which can be flushed out clean," he insisted.