BANGALORE: In what could clean up the sewage-choked valleys of the city, the Bangalore Water Supply and Sewerage Board (BWSSB) will soon take up linking of the main sewers to its treatment plants on the outskirts of the city.

Instead of being directed to a treatment plant, the city's sewage flows into stormwater drains, which are meant to carry rainwater — one key reason why flooding is common during rains.

Since the stormwater drains are linked to the city's lakes and the two rivers Arkavathy and Vrishabhavathi, it has polluted these water sources and contaminated ground water.

Under the Jawaharlal Nehru National Urban Renewal Mission, the water board has submitted a project report to the Union Government for approval to remodel 80 km of main sewage lines, which lie along the seven valleys of the city, for Rs. 176.75 crore.

The valleys include four main ones — Hebbal, Challaghatta, Koramangala and Vrishabhavathi — and three minor valleys — Tavarekere, Arkavathy and Katriguppe. In another project, the BWSSB will remodel 136 km of main sewage lines and 3,400 km of smaller sewage pipes, also called lateral pipes.

"Remodelling means increasing the diameter of the pipes wherever necessary and strengthening them so that they can bear the load," Chief Engineer (Waste Water management) Basavaraj told The Hindu .

"We actually have the capacity to treat all of the city's 500 million litres of sewage and make them reusable. But our treatment plants are working at reduced capacity because there is not much inflow of sewage to these plants," he said.

The treatment plant at Koramangala and Challaghatta valleys treat 120 million litres per day (MLD) of sewage when its capacity is 248 MLD. The treatment plant at Hebbal treats 35 MLD when its capacity is 60 MLD, Mr. Basavaraj said.

The treatment plant at Yelahanka works at 5 MLD when its capacity is 10 MLD and Vrishabhavthi treatment plant treats only 110 MLD when 183 MLD is its total capacity.

Printer friendly page  
Send this article to Friends by E-Mail