Bangalore could well become the first city in the country to get water that is a mixture of purified sewage water and treated natural drinking water.

This could happen in three years if the state government approves Bangalore Water Supply and Sewerage Board’s (BWSSB) plans.

According to official sources, the BWSSB has entered into an agreement with the Singapore government to share the technology required to treat sewage to potable levels.

Officials from Singapore have already conducted two workshops to train BWSSB officials about the treatment technologies that are being used in Singapore.

Two more workshops will be held between November 11 and 16 for this purpose.

The BWSSB has begun preparing a detailed project report (DPR) to pump 70 Million Litres a Day (MLD) of tertiary (the final stage in purification) treated sewage from Vrishabhavathi Valley near Mysore Road and pump it to Arkavathy river near Tavarekere.

The treated water will flow from Tavarekere to Thippagondanahalli (T G Halli) Reservoir, where 30 per cent treated water will be mixed with 70 per cent rain water and pumped to the city after further treatment.

As the sewage will be treated through the reverse osmosis process, all impurities will be removed to make it suitable for potable purposes.

BWSSB Engineer-in-chief T Venkatraju said, “We had mooted this plan long back and we had put it on hold fearing public opposition.”

Now that we have created enough awareness, we are planning to take up the project and we have formed a partnership with Singapore as part of their cooperation programme to take the plan further. They are the pioneers in using tertiary treated sewage for potable purposes, added the BWSSB Engineer-in-chief

‘Safe for Consumption’

Environmentalist A N Yellappa Reddy said, “The BWSSB will be forced to supply the treated sewage sooner or later. Sewage becomes potable when it is treated to tertiary levels. Moreover, when the tertiary treated sewage is allowed to flow on gravitational force for some distance, its quality improves due to the process of oxidation. Whatever little organic matter is left in the water will be absorbed by the soil. Therefore, the water will be safe for consumption.”

“Even Cauvery water contains a lot of organic matter as a lot of sewage is discharged into it along the course. Therefore, there is no harm in pumping tertiary treated sewage for potable purposes,” he felt.