New project to ensure sewage flow into treatment plants

Proposed pipe network aims to divert waste water from SWDs

In the absence of a proper conveyance system between the underground drainage (UGD) and sewage treatment plants (STPs), the Bangalore Water Supply and Sewerage Board (BWSSB) has proposed to rehabilitate and replace old sewer lines in the city’s core area. The project would also help in diverting waste water flowing into the 840-km stormwater drains.

Called the Environment Action Plan - C, the Board would replace more than 100 km of UGD network mainly in Gandhinagar, Malleswaram, Srirampuram, Rajajinagar, Vijayanagar and Nayandahalli among others, on the basis of “area’s population and the condition of the pipeline”.

BWSSB chairman Tushar Girinath told Deccan Herald that the project would cost Rs 640 crore, which includes two additional works related to sewerage. 

At present, the Board has entrusted the work of preparing a detailed project report to Tata Consultancy Services (TCS) to study the status of UGD lines in the core area connecting four major valleys. “There was no comprehensive study related to the condition of UGD lines in the core area, current population strength and the sewage load in different valleys. The DPR would include all these issues and we would replace and rehabilitate pipelines based on this report,” a BWSSB official explained.

Later, the Board would write to the state government for approval. It will take four years to implement this project, which includes replacement of old lateral and trunk sewers in the core of the city, he noted.

Earlier, the BWSSB had implemented the Environment Action Plan (EAP) - A & B in two separate phases to rehabilitate 33 km and 70 km of sewer lines at a cost of Rs 47 crore and Rs 176 crore respectively. While the EAP - A has been completed, work on EAP - B is almost over, he said.

In the core area, about nine lakh households are connected to the sewer lines, set up by the BWSSB. On the other hand, roughly one lakh households are letting sewage into storm water drains.

Former, BWSSB engineer and subject expert M N Thippeswamy opined that only 500 million litres per day (MLD) of sewage is reaching 17 STPs, which have the capacity to treat 721 MLD of wastewater. “This is because the sewer network is ageing or totally absent. The Board needs more than Rs 1,000 crore to set it right with quality pipelines that would last the next 100 years. Rs 400 crore is meagre,” he said.

He also mentioned that the sewage lines are not connected to the treatment plants in Koramangala and Challaghatta Valley (248 MLD) and Vrishabhavathi Valley (180 MLD), which are not working to their capacity. Hebbal valley treatment plant (60 MLD) gets more.