Deccan Chronicle 07.11.2009

Zero sewage in a year?

Bengaluru, Nov. 6: The BWSSB appears to have at last received a wake-up call to keep sewage and garbage out of stormwater drains, so essential to prevent flooding in times of heavy rain. It is working on a Rs 35 crore pilot project, titled Zero Flow for Hebbal valley to prevent sewage from entering storm water drains and emptying into water bodies, contaminating them.

The project has not come a day too soon as only 300 to 350 MLD of the 720MLD of sewage generated by the city is treated, while the rest finds its way into the storm water drains in the absence of a proper sewage network in the city. Also, it is estimated that at least 15 per cent of people in city directly discharge sewage into stormwater drains.

The problem has been compounded by the 68 km long sewage pipelines running inside storm water drains often being damaged while the drains are being de-silted by the BBMP.

While the problem is huge the BWSSB has decided to tackle it one step at a time. To begin with a 9 km long sewage line found inside storm water drains will be replaced by parallel pipelines laid on either side of the drain at a cost of Rs 2 crore, says S.M. Basavaraju, chief engineer, waste water management in the civic agency.

The BWSSB is acquiring five metres of land on either side of the drain to lay the parallel lines. It also plans to replace over 25 year old trunk sewer lines of over 450mm in diameter running over 16 kms at a cost of Rs 33 crore in Hebbal.

The project which will be financed under Mega city funding and also by the BWSSB, is expected to start in a month and be completed in a year, according to Mr Basavaraju. The BWSSB has already replaced a 9 km long sewage line in Koramangala, Chelagatta and Vrishabhavathi valleys, under the National River Conservation Plan, and Environmental Action Plan A.

Once the pilot project is completed, it will be extended to these three valleys and their sewer lines inside storm water drains will also be replaced under Environment Action Plan 3, explains BWSSB chairperson P.B.Ramamurthy. The project could give a fresh lease of life to 80 percent of water bodies in the city which are currently dumped with sewage and also prevent contamination of the ground water, which has made 80 per cent of borewells unfit for supply of drinking water.