JOIN USTreated sewage can solve water woes, say experts
As much as 1.7 million people in the City would get water for domestic consumption even if 50 per cent of the waste water flowing in the stormwater drains is effectively preserved and treated, according to groundwater geologists.
In a book, “Bengaluru Water Resource Management – Challenges and Remedies” written by two former groundwater geologists, K C Subhash Chandra and G V Hegde, the authors have said that the City generates 1,100 million litres of sewage per day and out of this, if at least 70 per cent (770 mld) is treated to secondary level, and of this if 60 per cent (462 mld) is again treated to secondary level, the water will meet the needs of nearly 3.3 million people in the City.
The geologists have said that in the case of tertiary treated sewage water, an estimated 168 Mm3 per year (million cubic metres per year) is not considered for domestic purposes or potable use for the existing piped water system.
The treated water can be supplied for sanitation services, gardening and other non-domestic purposes through ‘dual piped system.’ If these measures are effectively implemented, altogether it would meet the water requirement of about 14.3 million people at 140 LPCD (litres per capita per day).
Subhash Chandra said that unless there was a dearth of water resources, people would not understand the need for water conservation. He said that if the Cauvery water supply scheme had not been implemented, people would have understood the need to preserve lakes and water bodies.
Without dependency
In the book, the geologists have said that water sufficiency could be reached without any dependency on any other distant river or groundwater resources. The geologists have said the environmental, hygienic and socio-ecological conditions of the City will be improved by addressing the waste water discharge and its total treatment along with the systematic management of solid waste.
The Bangalore Water Supply and Sewerage Board has proposed to set up a 100-mld tertiary treatment plant at the Vrishabhavathi valley. The water from this plant could be used for potable purposes in future. A detailed project report has been prepared and submitted to the government for further consideration.