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.