Muddy waters: Sewage treatment plans stagnate

Bengaluru: Located in what was once the fringe of Electronic City in Bengaluru, the Shikaripalya lake would have ended up as a sewage collection tank, had it not been for the efforts of a group of residents of the village.

“After the intervention, the entry of sewage to the lake was prevented. It is now diverted to Maragondanahalli lake, about 2.5 km downstream,” said Mani Rajan, a member of the group. At Maragondanahalli lake, the sewage is impounded in pond-like structures. “It smells in that area. The larger lake portion does not get the wastewater. That is the temporary relief,” Rajan said.

Throughout India, wastewater is diverted from one point to another, drain to lake, lake to river and then to the sea. Even though surface water sources are increasingly scarce or polluted, treating wastewater is still not a priority. According to Niti Aayog’s India Climate and Energy Dashboard, out of 729 districts in India, 527 face water scarcity, and 21 face absolute scarcity.

The value of treated water for non-potable use, in domestic, irrigation and industrial sectors has been outlined by many studies. However, treatment of wastewater is still slow to catch on with numerous cities dumping sewage into drains and rivers. In some instances, as in the case of Bengaluru, crores of rupees have been spent to pump treated wastewater to nearby towns.

The Supreme Court and the National Green Tribunal have tried to check the pollution of water bodies and improve wastewater treatment methodologies. More than 50 years after the Water (Prevention and Control of Pollution) Act of 1974 identified wastewater as a source of pollution, India continues to struggle with sewage treatment.

Between 2017 and 2023, Bengaluru recorded 61 separate incidents of fish kills in its lakes, a direct result of an increase in organic load in sewage reducing dissolved oxygen content. The Action Aid Association, which conducted a study last year on such occurrences, noted that four lakes that had witnessed multiple fish kill incidents had STPs.

A growing body of research has highlighted the threats posed by inadequate treatment of wastewater. Over the last few years, toxic heavy metals from sewage have been found in grains, fruits and vegetables.

Monitoring and compliance

The Supreme Court’s 2020 deadline for all states to treat 100% of wastewater has long passed. It has been five years since the Central Monitoring Committee (CMC), under the Union Ministry of Jal Shakti, began monitoring the progress of sewage treatment in states.

The committee was tasked with this role by the National Green Tribunal (NGT) after a Central Pollution Control Board (CPCB) study showed over 300 river stretches across India were polluted by sewage.

Data from 27 states and Union territories shows as of June 2024, just about 29% of 45,000 mld of sewage generated is treated. Wastewater that could fill 13 lakh tankers of 10,000-litre capacity is being dumped into the environment today.

Worryingly, no state has published sewage generation and treatment information in rural areas despite the NGT specifically seeking these details out five years ago.

A review of data submitted shows that no state provides clear data on the quantity of freshwater used per day, the generation of waste, its treatment and the use of recycled water.

Even taking the data submitted by the states at face value, the progress in enhancing the treatment capacity is dismal. As of 2020, 27 states reported that they had untreated sewage of about 14,000 mld. Four years later, the states have been able to collectively reduce 1,000 mld of sewage from entering the freshwater sources.

In the September quarterly meeting, the CMC expressed concern over many states, including Delhi, Tamil Nadu and Karnataka, failing to adhere to their deadlines in the construction of sewage treatment plants (STP). “That the timelines of different under construction STPs and upgradation of 18 STPs are being continuously revised is a matter of concern,” the committee noted in its review of Delhi’s progress.

During the review, the committee chairperson, Debashree Mukherjee, also observed the lack of utilisation of STPs to their full capacity in at least five states, including Maharashtra, Gujarat, Tamil Nadu and Karnataka. 

In Gujarat, she noted, even after the construction of sufficient numbers of STPs, there was no improvement in the water quality of priority 1 rivers.

Challenges

On their part, states submitted that they were struggling to fund projects as building underground drainage (UGD) networks and constructing STPs is proving to be costly. The case is best illustrated by Gujarat. The state’s Secretary for Urban Development explained the three-fold problem that the state faced. First, there was a lack of household connections to the existing UGD network. A survey found that 12.9 lakh households remained unconnected. “The state government is now providing Rs 7,000 to owners to encourage connecting households to sewer networks,” he stated.

Secondly, the state is trying to build the UGD network in ‘outgrown and missed out’ areas, with projects worth Rs 5,000 crore being planned. “(The) third issue is that a few Nagar Palikas are not able to run and maintain the STPs properly due to fund paucity and high (operation and management) cost. The state government has decided to provide financial and technical assistance to these ULBs,” he said.

Use of treated water

Meanwhile, in Bengaluru, Rs 2,744 crore is being spent on the K C Valley and H N Valley projects, which seek to pump treated wastewater into Kolar and Chikkaballapur districts. The state has also spent over Rs 5,000 crore on the Cauvery stage V and has announced a budget of Rs 7,200 crore as a part of stage VI.

A senior official agreed that reusing the treated water would reduce the capital involved in sourcing freshwater. “There is an element of fait accompli in Bengaluru’s model. Thousands of crores of rupees have been spent to pump fresh water from 100 km away. By reusing treated water, we can avoid the new projects in the pipeline to draw additional water from Cauvery. However, we are investing heavily in treating water and pumping it out of the city to villages,” he said.

There is a need for Indian cities to move away from large-scale and capital-intensive sewerage infrastructure in favour of a decentralised system to collect, treat and reuse wastewater, suggested a report by the Centre for Science and Environment (CSE), released earlier this month. 

“The case studies of Delhi and Bengaluru demonstrate the implementation of decentralised STPs located in different parts of the city. The treated water from these STPs is reused for various purposes, including lake recharge, recharge of shallow aquifers, industrial supply, and horticulture… This methodology eliminates the necessity for constructing extensive and often costly reuse infrastructure,” the study said.

The state environment impact assessment authorities (SEIAAs) have the power to mandate 100% local usage of treated water while issuing clearances to industries and large apartments. “In Karnataka, we have been insisting on industries to ensure 100% reuse and many of them have complied while some, especially old ones, are struggling due to the gaps in technology. In apartments, we have made STPs compulsory but not the reuse of treated water. The government’s latest policy, in allowing the trade of treated water, has helped many apartments where the scope for using treated water is limited,” said an SEIAA Karnataka member secretary.

Environment authorities in states, tasked with ensuring local utilisation of treated water, have not been able to enforce it. Earlier this month, the Comptroller and Auditor General report revealed that the Coastal Zone Regulation Authority of Tamil Nadu, a crucial body, had cleared 114 of 175 project proposals, without checking the necessary documents. Earlier, the CAG had found that the Karnataka State Pollution Control Board had issued clearances to highly polluting, red and orange category industries without any inspections.

Quality issues 

Any push for the reuse of wastewater can happen only after states ensure that the quality of treated water meets the standards set by the CPCB. However, a review of data submitted by states shows otherwise. The national monitoring committee noted in September that of the 154 STPs in Maharashtra, 61 STPs, including a 757 mld plant at Worli and 797 mld plant at Bandra in Mumbai were
non-compliant. 

The number of non-compliant STPs was 46 in Gujarat. It was followed by Himachal Pradesh (35), Punjab (28), Delhi (17), Karnataka (12) and others. In Punjab, Gujarat and many other states, even industrial effluent treatment plants failed to comply with the CPCB standards.

States have a long way to go in building trust to reuse treated water but they do not have much time. The CSE study also warned that the thirst for freshwater has led to inter-and intra-state, intra-city, and rural-urban water conflicts. “Add to all this the ravages being wrought by climate change, which is manifesting itself as an intensification of the water cycle,” it noted, stressing the need for a model where recycling and reuse of wastewater is prioritised.

Rural context

Untreated wastewater in rural areas is a major concern in view of the direct impact it has on the health of people and cattle. While the government estimates that 2 lakh deaths take place due to lack of clean water, a Lancet study in 2022 said that the number of such deaths in 2019 was 5 lakh. 

Subrata Chakraborty, senior programme manager at the Centre for Science and Environment (CSE), noted that approaches to deal with sanitation issues in rural areas would significantly differ compared to urban areas. “In rural areas, we have distinct grey water. And grey water management is an important component. In urban areas, grey and black water are mostly mixed. Therefore, intervention strategies and technologies differ. The scope of adopting more decentralised intervention is higher in rural areas,” he added. Black water includes water from toilets and bathrooms, which contains faecal matter, while grey water is water from wash basins, sinks and kitchens, which has a lower level of contamination. 

Decentralised intervention is particularly relevant for villages situated in undulating terrain or those located in hilly regions. Some states have reported that they are focusing on decentralised treatment systems by building faecal sludge treatment plants. There is, however, no clarity on the treatment of grey water which will continue to pollute the water bodies.

To a question on the lack of clarity about the treatment of sewage in rural areas, Sumita Singhal, co-author of the CSE study ‘Waste to worth’, said there was a need to prioritise components of different government programmes so pollution levels can be reduced. “We already have various missions that support rural development with different approaches and perspectives. The key question is the effective implementation of these missions,” she said, pointing to a lack of awareness and funding gaps.

Invasive species

Less talked about is the matter of untreated sewage contributing to the silent disaster of invasive species, slowly destroying rich local biodiversity. The contamination compounds climate change, which makes survival difficult for local flora and fauna and creates a conducive situation for invasive plant and animal species to thrive. Water hyacinth, an invasive plant introduced by the British, has become ubiquitous in most lakes. The tadpole snail from North America, a highly invasive species that has threatened local species, found a home in the sewage drains of Kolkata and Assam in the 1990s and has now been reported from many parts of the country. 

Contaminated water

In Cuttack, Odisha, researchers pointed to the use of contaminated water with high concentrations of cadmium, lead, nickel, chromium and copper. Researchers who studied water samples in Kanpur and Varanasi of Uttar Pradesh had warned of ‘definite adverse impact’ on ecology as far back as 2004. 

In Bengaluru, studies by the Indian Institute of Science and the state government’s Environment Management Policy Research Institute found heavy metals in the vegetables grown using water sourced from lakes, posing risks of deadly diseases, liver toxicity and cancer. Last month, DH reported on researchers finding the banned pesticide DDT in River Arkavathy, with samples showing a concentration of the chemical 75 times above safety limits.

Way forward

To a question on the reforms needed in the policy for better management of the water bodies, Debarshee Dasgupta, a Senior Research Associate with Centre for Policy Research’s Transboundary Rivers, Ecologies, and Development Studies programme said there was an urgent need for the states to revisit spatial planning.

“In our view, the states should revisit their spatial planning laws, frameworks, and practices to regulate growth around water bodies. The spatial regulations should also address the concerns of small towns and cities, and peri-urban areas, which in many cases are neglected. The least they can do is to give effect to existing laws and judicial decisions about protecting the water bodies, rivers, and floodplains,” he said.