Bengaluru’s sewage treatment conundrum

When fishkill in lakes tells a tale

Sewage contributes to 70 per cent of the pollution load to the water bodies in Bengaluru. More than a decade after the Karnataka State Pollution Control Board (KSPCB) first came up with guidelines for treating wastewater, fishkill has become a regular phenomenon in several lakes while many lakes including the Bellandur and Varthur.

“We are not even halfway into 2023 but already recorded 11 fishkills in eight lakes. Unfortunately, the entire administrative set-up has normalised such incidents,” said Raghavendra Pachhapure of Action Aid. He had documented fishkill in 16 lakes in 2022. Many of these lakes are in the newly added 110 villages where there is no sewage network.

As per the Bangalore Water Supply and Sewerage Board (BWSSB), Bengaluru generates 1480 million litres per day (mld) of wastewater which is supposed to be treated in 36 sewage treatment plants (STPs) with a total capacity to process 1527.5 mld.

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“As of now, we are treating about 1200 mld in the STPs. Two linking works between underground drainages and STPs are pending due to delays in getting clearances and other issues. Once that is done, we hope to treat all the city’s wastewater,” an official said.

Interestingly, when BWSSB officials say “city’s wastewater”, they are yet to include the 110 villages which have seen rapid urbanisation since they were added to the BBMP limits. As part of Cauvery Stage V, the BWSSB has set the target of supplying 770 mld of water. The BWSSB is spending Rs 800 crore for the project.

“The thumb rule is that 85 per cent to 90 per cent of the water received by a household will come out as sewage. As of now, there is no mechanism to handle the wastewater in those areas. The UGD link work needs to be completed before we can see any progress,” another official explained.

Negligence by KSPCB

The KSPCB, entrusted with the power and responsibility to implement the Water (Prevention & Control of Pollution) Act, 1974, has been pulled up by courts for failing to enforce the rules despite repeated directions.

Activists believe unchecked irregularities, coupled with political appointees ruling the roost, have reduced the statutory body into an entity giving approval for projects.

“For years, the government has been blaming the apartments for the pollution but failed to provide any guidance to help apartments comply with the rules. The STP guidelines they issued in March 2021 were so erroneous that they withdrew it the moment people started asking questions,” said Nagesh Aras, who has been tracking the issue for the past 10 years.

A KSPCB official acknowledged that there was no guideline at present for apartments on STP installation and maintenance. “Our guidelines are limited to the quality of the water discharged by the STP. We made an attempt but had to withdraw the document after it received opposition,” he said.

Officials believe about 3,500 apartments in Bengaluru have installed STPs. However, ensuring that the treated water complies with the standards set by the Central Pollution Control Board (CPCB) has become a herculean task.

“Only about 10 per cent of the STPs meet all the standards. Compliance is poor in the remaining ones as they fail to meet at least one of the parameters. We (KSPCB regional officers) pay surprise visits to detect any non-compliance or violations. Notice is issued in case of non-compliance and rectification is done. However, we can’t monitor it all the time,” a senior official said.

Ask about the reasons, and KSPCB officials point to a host of issues, from staff shortage to conflicting rules issued by the KSPCB and the BWSSB, and the lack of infrastructure.

KSPCB chairman Shanth A Thimmaiah admits to the staff shortage. He says more people will be hired soon, but for now, KSPCB is managing with existing staff. “We ask STP owners to conduct a unitwise performance efficiency study and to take mid-course corrections for deviations if any. We compare it with our own reports while considering Consent for Renewal applications,” he says.

Ambiguities in rules

KSPCB’s monitoring efforts have been severely undercut by systemic problems and missteps by various authorities. The glaring example is the amendments made to the rules mandating the setting up of STP.

In 2016, the government made it mandatory for apartments with 20 or more residential units to have an STP facility. However, the BWSSB ran into controversy as it tried to enforce the rule on old apartments where STP installation was impractical due to lack of space and penalised residents for non-compliance.

Then came the 2018 amendments with up to 50 units being exempted from installing STP as long as they were connected to an existing underground drainage network. “There was a flawed approach to implementing the 2016 order. Instead of correcting it, we made a complete U-turn,” an official said.

BWSSB engineer-in-chief Suresh B said they do not have data on the number of apartments releasing sewage into the stormwater drains. “We do not maintain that data,” he said. This results in inaction by all bodies on the violations including BBMP and KSPCB.

Apartments take consent for the establishment (CFE) of STP in the initial face by submitting the design and other details of the plant. After setting up the STP, they need consent for operation (CFO) of the same. “There are at least 10 cases where we have seen that the established STPs are entirely different from the approved designs. But nobody asks any questions and everything is swept under the carpet,” Aras said.

Meanwhile, KSPCB’s own water quality data for 118 lakes shows that for May, 76 lakes had D quality (fit for the propagation of wildlife, fisheries) while 28 lakes have E quality (fit for irrigation, industrial cooling, controlled waste disposal). The data for the rest of the lakes are not available.

This shows that lakes in the city centre were not really in good shape, says Pachhapure. “The KSPCB has not been providing full details of the contamination of the lakes. Their reports only show the grade of the water quality where we don’t get to know the biological oxygen demand, chemical oxygen demand and or coliform contamination in the water. This needs to change,” he says.

Aras said the “opaque” working system of the KSPCB was an indicator of both incompetence and callousness. “People who lack technical expertise are put in key positions. On the other hand, people at the top positions of the Board fail to do anything as it conflicts with their vested interests.”

Missing deadlines

Meanwhile, as Bengaluru expands every day, the violations have only led to the appointment of committees to look into the problem with their recommendations forgotten in the clamour for growth. Expert committee reports, including the Laxman Rau Committee Report (1987), Justice N K Patil Committee Report (2011) and the Mahendra Jain Committee Report on the Restoration of Bellandur and Varthur Lakes (2016) have been forgotten.

The state government committed before the National Green Tribunal that it will treat all the “1400 mld” sewage generated by Bengaluru by the end of March 2020. The deadline has since been shifted to December 2024 and there are misgivings within the KSPCB about the new target.

Neither KSPCB nor BWSSB officials have an estimate about the quantity of water from apartments and individual houses. Activists have long pointed out that the polluter-pays-principle has been ignored when it comes to buildings built in violation of the sanctioned plans.

The BWSSB estimates the sewage flow rate as per the standards set by the Central Public Health Engineering Organisation. For domestic connections, sewage generation is estimated based on the area of the property. However, over the last 10 years, properties measuring between 1200 sq ft and 2400 sq ft have been used to build flats, often in violation of rules.

“There are cases where water and sewage connection is given based on the approved plan for two or three floors but the building would have five floors with one or two residential units in each. The lack of proper data on sewage generation makes it difficult to plan treatment,” an official said.

Quick action needed

A retired KSPCB scientist says the government is yet to wake up to the pollution caused by the industries. “The Peenya industrial area still doesn’t have plants to treat the industrial effluents. It is true that the KSPCB has stopped giving permission for new polluting industries, especially electroplating units. However, what happens to the existing ones? Monitoring them is not an easy task,” he adds.

M N Thippeswamy, retired BWSSB chief engineer who oversaw the implementation of secondary treatment of sewage during his service, says the government and the Board, in particular, were staring at a major crisis.

“The delayed monsoon should have woken up the decision-makers by now. Cauvery River is already over-exploited. Climate change is upon us and we can’t rely on monsoon to meet the growing needs of the ever-growing Bengaluru. The storm runoff and sewage need to be treated and used for non-potable use in the first stage. In the future, we may have to depend on them to fulfil drinking water needs,” he cautions.

The BWSSB is planning to install nine more sewage treatment plants in the northern and eastern parts of Bengaluru. Meanwhile, a KSPCB official said a meeting of officials from the Urban Development Department, BBMP, BWSSB and the KSPCB will be held soon to discuss the issue. “It’s a complicated matter that requires coordination. We will put all the issues on the table during the meeting,” he added.