Govt working out treating Bengaluru wastewater for drinking, crops

The state government has started discussing the feasibility of tertiary treatment of Bengaluru’s sewage to make it safe for drinking besides recharging groundwater in the city’s parched neighbourhood, Minor Irrigation Minister NS Boseraju said. 

The government is treating Bengaluru sewage and using that to fill up lakes in Kolar, Chikballapur and other regions around the city under the pioneering Koramangala-Challaghatta (KC) Valley and Hebbal-Nagawara (HN) Valley projects. 

Boseraju told DH that the government, at present, is providing secondary treatment to the sewage. “It is meant only to fill up lakes for groundwater recharge,” he said. “But there are expectations that the government should start tertiary treatment.”

According to Boseraju, the KC Valley and HN Valley projects have improved groundwater levels in the arid regions near Bengaluru. 

“If tertiary treatment is done, then the water can be used for drinking as well as irrigating crops. Right now, farmers are not using the lake water. They are benefiting from the groundwater that has improved as a result of the lakes being filled up,” Boseraju explained. 

Boseraju pointed out that former chief minister Basavaraj Bommai, in his February 2023 budget, promised tertiary sewage treatment. Even Chief Minister Siddaramaiah promised this to the people of Kolar, especially when he was supposed to contest the Assembly election from there. “So, there are these commitments. And, people want tertiary treatment,” the minister said. 

Apparently, Food & Civil Supplies Minister KH Muniyappa, a seven-time Kolar MP, is also in favour of tertiary treatment. 

Under the first phase of the KC Valley project, a total of 143 lakes in Kolar have been filled up at a cost of Rs 1,342 crore. Under the second phase, 276 lakes will be covered at a cost of Rs 455 crore. The HN Valley project has filled up 65 lakes in Chikballapur at Rs 947 crore. 

Meanwhile, however, Bengaluru is not generating enough sewage. 

According to Boseraju, the Bangalore Water Supply and Sewerage Board (BWSSB) is required to supply 730 MLD sewage for the two projects. But the utility is supplying 420 MLD, resulting in a shortfall of 310 MLD. 

This is creating difficulty in ensuring that lakes are 60% filled as per project guidelines, Boseraju said. “The maintenance of water level in lakes is the only demand farmers have in that region,” he said.