How Bengaluru’s Domestic Wastewater Is Helping Parched Kolar
Read how domestic wastewater measuring 300 million litres/day from Bengaluru is treated and sent to parched Kolar
The beaker of clear water in the hands of K Dhananjaya, 57, executive engineer with the Bangalore Water Supply and Sewerage Board (BWSSB), looked good enough to drink. But it contained sewage water, treated at the Bellandur sewage treatment plant (STP) as part of a unique water-recycling experiment.
More than 300 million litres per day (MLD) of a targeted 440 MLD--nearly one-tenth the water demand of Mumbai or the capacity of 176 Olympic-size swimming pools--of this secondary treated domestic sewage water is being transferred from Bengaluru to the adjoining, parched district of Kolar and parts of Chikkaballapur through the Koramangala-Challaghatta (KC) Valley project. This water is then pushed into 126 lakes scattered around Kolar, many of them left dry by successive droughts.
The purpose of the project is to rejuvenate the depleted groundwater in the drought-hit Kolar region by allowing the treated water to percolate down from these lakes and tanks. This, said experts, will help farmers who are largely dependent on groundwater for irrigation and if successful, the project could be replicated in the other water-starved regions of India.
“This can be a model for the country for sharing wastewater for agricultural use,” S Vishwanath, Bengaluru-based water conservation expert, told IndiaSpend.
The water reaching Kolar is strictly not for direct irrigation because once it reaches one lake, it has to percolate and through gravity-based flow, move to fill subsequent tanks. It benefits farmers only by raising the groundwater level in the region.
The experiment comes at a time when India’s estimated per capita availability of water by 2025 is estimated to be 1,341 cubic metre. (An area with an annual per capita availability of less than 1,700 cubic metre per person is considered to be water-stressed, and less than 1,000 cubic metre per person, water-scarce.) The current availability may further fall to 1,140 cubic metre in 2050, bringing India closer to scarcity, IndiaSpend reported on December 30, 2017, citing a 2017 assessment by the ministry of water resources. In the decade ending 2011, India’s water availability fell by 15 percent
Further, India is the world’s largest consumer of groundwater, extracting twice as much as China, the world’s most populous country. India extracted 250 cubic km of groundwater in 2010--1.2 times the capacity of the world’s biggest dam--of which 89 percent was used for irrigation.
Experiments like the Kolar one are on elsewhere as well to make better use of recycled water and stave off scarcity. The Nagpur Municipal Corporation, for example, is expected to be the first in the country to treat and reuse over 90 percent of the 525 MLD sewage it generates, The Times of India reported in January 12, 2019. The Maharashtra State Power Generation Company intends to use 190 MLD of this water for its thermal plants. Noida, in Uttar Pradesh, has also increased its treatment capacity to become a ‘zero-discharge’ city by recycling 100 percent of its sewage water.
Nearly 63 percent of the 61,754 MLD sewage generated, nationally, is untreated while the national treatment capacity is 22,963 MLD, noted the government-run ENVIS (Environmental Information System) Centre on Hygiene, Sanitation, Sewage Treatment Systems and Technology data in May 2019.
But the Kolar project which attempts to reimagine the usage of urban wastewater is not without challenges. It was halted by the Supreme Court in January 2019 due to reports of the presence of heavy metals in the recycled water and its likely effect on groundwater sources. The court lifted its stay in April 2019.
We spoke to farmers across Bellur and Narsapura panchayats in Kolar, some 70 km east of Bengaluru, to understand how they respond to the project. Some, who observed an increase in the water levels in their wells, were happy with its impact. Others were anxious about the quality of the water and the chances of it contaminating water sources.
Farming in the Time of Drought
Karnataka has 16 of the 24 most drought-prone districts in India, of which Kolar is one among six permanently drought-prone ones, the state government noted in the assembly in December 2018. In 2019, 30 taluks [administrative unit] in 13 districts, including Kolar, were declared drought-hit.
In 15 years to 2015, only three years in Karnataka--2005, 2007 and 2010--witnessed no drought, as per a 2017 Karnataka State Disaster Management Monitoring Centre’s drought vulnerability assessment report that IndiaSpend cited in a report published on May 8, 2018. The district has zero net groundwater for future use, and has the highest groundwater extraction--211 percent--in the state, noted the 2017 Dynamic Groundwater Resources Assessment of India.
Farmers in the district have been innovative in using drip- and micro- irrigation. But the KC Valley project is “a game changer”, J Manjunath, deputy commissioner of Kolar, told IndiaSpend. “The failure rate for borewells (whose average depth in Kolar is nearly 1,500 feet) is more than 30 percent and in some parts during summer it was 50 percent,” he said. “The farmer will have to spend close to lakhs for digging a new borewell including motor, piping, and other infrastructure.”
So far, the minor irrigation department has pumped 2.5 tmcft of treated water and the aim is to pump 5.5 tmcft within the year, C Mruthyunjaya Swamy, secretary, minor irrigation department told The Hindu on November 12, 2019.
“The daily discharge of 310 MLD of treated water from the BWSSB is being pumped into the project, with the Lakshmisagar lake being the first discharge point,” he said. (Swamy did not respond to multiple requests for an interview from IndiaSpend.)“The daily discharge of 310 MLD of treated water from the BWSSB is being pumped into the project, with the Lakshmisagar lake being the first discharge point,” he said. (Swamy did not respond to multiple requests for an interview from IndiaSpend.)
The authorities were clear that this secondary treated water is not for direct irrigation use and not fit for direct consumption. “The BWSSB only collects domestic sewage and the STPs are designed for such treatment,” Dhananjaya from BWSSB told IndiaSpend.
Farmers found using water pumps to draw this water are penalised, officials told IndiaSpend.
Primary treatment is the minimum level of preapplication treatment required for wastewater irrigation, as per a Food and Agriculture Organization note on wastewater treatment. “It may be considered sufficient treatment if the wastewater is used to irrigate crops that are not consumed by humans or to irrigate orchards, vineyards, and some processed food crops,” as per the note. Secondary treatment further treats effluent to remove residual organics and suspended solids.
The domestic sewage water is treated in Bellandur to standards set by government agencies, said Dhananjaya. “It is a complex institutional setting,” said Vishwanath pointing to the multiple agencies at work: The treatment is done by the BWSSB and the transportation by the minor irrigation department while the lakes belong to panchayats, the groundwater is under the purview of the groundwater authority, and the regulatory framework is with the pollution control board.
“This is one of the largest transfers of wastewater for agriculture project,” added Vishwanath. “Farmers are happily using it.”
‘Yield has Gone Up’
Sudha Ramlingaiah, 32, a farmer from Bellur panchayat, was hard at work under the mild October sun on her family’s two-acre farm located a kilometre from Laxmisagar lake, the first receptacle for the recycled water from Bengaluru. The family grows ragi (finger millet), which does not require much irrigation, and some vegetables.
“The water in the wells have increased,” she told IndiaSpend. “Initially it was smelly, but now it seems clean. But there are mosquitoes.” A well near her farm which had almost dried out now seems to have water, she added.
“Even at 1,800 feet we usually do not find water here, but this year we have been able to grow two crops and we have not had to work on others’ farms,” Sudha Ramlingaiah said, adding that water availability will allow her to grow more vegetables. The farm output this year rose by Rs 50,000 due to increased produce. But this is happening on other farms as well creating a labour shortage in the area.
The project has benefitted Uday Kumar, another farmer in Bellur who owns a 3.5-acre farm that grows tomato, brinjal, chilli, carrots and roses--all rain-dependent. “Earlier, the lakes in Kolar used to fill up only during rains, but now there is water all the time,” he said. “We are getting water at 1,000 feet now, unlike before when we barely got any at that depth.”
Farmers who till now could raise Rs 30,000 through the sale of produce can earn upto Rs 1 lakh depending on the crop we grow and the market rate, he added.
‘It smells, of little use’
But 46-year-old Narayanaswamy, whose one-acre farm adjoins the Hosakere lake, was unhappy with the treated water which he claimed is bringing mosquito-borne disease into his village. “Initially we were happy to see the lake fill up but it smells,” he said. “Even animals don’t venture into it.”
In Narsapura, around 10 km from Laksmisagar, Raja Rao, 71, and Venkatesh V, 48, who have their farms across the Narsapura lake, are unhappy too.
“This water is not clean and has to be filtered: It has not helped us at all,” said Vekatesh who owns an acre where he grows carrots, beans and beetroot. “This water has not been released to us for farming, so it is not useful,” said Rao who owns an acre and two guntas (0.05 acres) of land where he grows vegetables like radishes, carrots, cucumber, and ragi.
The lake needs to be deepened further and the water channels need to be opened if the objective is for the water to improve groundwater, said Venkatesh.
In July 2018, the Narasapura gram panchayat distributed pamphlets cautioning against the use of water from the borewells located in the bed of the local lake because it was contaminated and smelt bad.
“We used the lake water which filled up during rains for our household needs,” said Rao. “Now no one even eats the fish caught from the lake, we do not even dip our feet in it.” The recycled water has not been able to improve water levels in the village because the soil does not allow it to percolate, he said.
The farmers are not allowed to pump recycled water from the lakes to ensure that all subsequent lakes receive adequate water, as we explained earlier. This has caused some resentment against the project in the area. “Our pumps get confiscated by the officials if we try to pump in this water,” said Venkatesh. “Then how is it useful for us?”
There have been around 30 cases of farmers trying to directly lift this water.
“Raids have been conducted where we have warned farmers, and subsequently seized their pump or motor, “We have asked officials to book a case against repeat offenders. Now the minor irrigation department is in the process of recruiting youth or home guards to keep watch at the lakes.”Manjunath, Deputy Commissioner
How can the system be made to work more effectively? “One way is to work with the government in monitoring the treatment of water and help improve water quality,” said Vishwanath. “The other is to help farmers judiciously use the water. There is significant potential for economic regeneration.”
A Legal Challenge
In July 2018, the Karnataka High Court restrained the government from pumping secondary treated sewage water to Kolar after a special leave petition was filed by Anjaneya Reddy, a Chikkaballapur resident and president of Shashwatha Neeravari Horata Samithi (or permanent irrigation agitation committee) which raised concerns about the quality of the water. In September 2018, the High Court issued a new order allowing pumping of water.
The Supreme Court which stayed the High Court order in January 2019 then vacated its stay in April 2019 which allowed the pumping of water noting that it complied with similar practices across the world and asked the petitioner to approach the High Court.
“We have lost 175 days due to the stoppage,” said Manjunath.
But the petitioner who filed the case believes that it is justified. “Kolar region already has water quality issues, and this water can cause groundwater contamination,” Reddy told IndiaSpend.
The water samples collected have heavy metals (cadmium, chromium, copper, lead, cobalt and zinc) above the standard levels and treated water has high ortho-phosphate (indicating pollution), nitrate and organic content, noted a September 2019 report of Centre for Ecological Sciences at Indian Institute of Science.
The contamination occurs because the STP does not have the capability to remove it, said T V Ramachandra, a senior scientist at the Centre for Ecological Sciences and lead author of the report. “In principle, I am not against the project,” he said. “I am against the government agencies doing improper treatment of sewage water.”
But the BWSSB contested this criticism. “There is no question of untreated water being released,” E Nithyananda Kumar, chief engineer (wastewater management) with BWSSB, told IndiaSpend. “Except for drinking, it [secondary treated water] can be used for anything.”
But the concern is that the water will percolate to groundwater sources and contaminate aquifers (the underground layer of water-bearing rock), countered Prince Isac, Reddy’s lawyer. “It may happen now or in a few years,” he said. “If tertiary treated water is provided, there is some satisfaction.”
The state government has informed the High Court that the Indian Institute of Science has been requested to study the environmental impacts of the KC Valley project, The Hindu reported on November 12, 2019.
“There are aspects that need improvement, but the project can be a model for the country for sharing wastewater for agricultural use,” said Vishwanath. “The current imagination is for the city to use it [its own wastewater] but this is a relevant model for India.”
(Paliath is an analyst with IndiaSpend. Rathod is a Bengaluru-based independent researcher. The article is published in arrangement with IndiaSpend)
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