Case Study: Successful Rejuvenation of a Bengaluru lake

Ecoparadigm’s natural on-site sewage treatment plant now allows only clean water to pour into Bengaluru’s Kundalahalli lake. This public-private project was supported by residents’ associations, the City Municipal Corporation as well as corporate bodies.

Bengaluru’s lakes are known to make news for all the wrong reasons. The familiar sight of the foaming and frothing of Bellandur and Varthur lakes due to extensive pollution has made it to the headlines, even in the international media. Once known as a city of lakes, Bengaluru is increasingly close to being declared unliveable. For years, Dr TV Ramachandra of the Indian Institute of Science’s Centre of Ecological Sciences has warned, time and again, that uncontrolled urbanisation has led to the drying and dying of lakes, and the city needs to pay heed. Anthropogenic activities such as the dumping of building debris and indiscriminate disposal of industrial effluents and sewage waste in the lakes have altered the physical, chemical as well as biological integrity of the urban wetland ecosystem.

The Kundalahalli Lake is situated in eastern Bengaluru and is spread across 30.5 acres, surrounded by tech-parks, multistoreyed buildings and slums. It was used to dump solid waste like plastics and construction debris, which piled up and overflowed onto the shore. The lake periphery was used for open defecation and the lake itself was a cesspool of sewage covered by water hyacinth.

In 2016, the Bruhat Bengaluru Mahanagar Palike (BBMP), the local residents’ welfare association and corporate offices in the area came together to form a publicprivate partnership to rejuvenate the lake. While the Brookefield Residents’ Association and BBMP managed to prevent encroachment and illegal dumping of debris, the central issue of rejuvenating the lake remained. This was when the residents’ association sought the expertise of Ecoparadigm, a Bengaluru-based environmental engineering company, which works on implementing solutions for sewage treatment and rain water harvesting, and has executed projects across 23 Indian states, and 10 countries spanning four continents. With several corporates pitching in for the funding, this INR 6 Crore project saw investments from all stakeholders.

Over nine months, Ecoparadigm planned, designed and executed a waste-water treatment plant using DTS (Decentralised Wastewater Treatment System) technology, which offers a stateof- the-art solution for adequate on-site wastewater treatment, taking maximum advantage of natural processes to achieve a reliable as well as an eco-friendly system. The DTS technology from Ecoparadigm works independent of power supply and daily surveillance, treating the wastewater steadily over time. It enables one to treat both grey water (from bathrooms, laundry and kitchen) and black water (toilets) with minimal maintenance, all the while being cost effective. The DTS system allows reuse of waste water for flushing in toilets and using kitchen organic waste for gardening.

The basic technology for treating waste water with DTS Technology includes a Settler, Fluidized Bed Reactor, Fixed Film Reactor, Planted Gravel Filter and Pond. The treated water is then discharged into the lake. Two Decentralised Treatment Systems (DTS) were installed at the lake that treat around 780 kilolitres of incoming sewage every day. This natural, eco-friendly DTS needs no energy, chemicals or manpower for water treatment.

To date, the DTS at Kundalahalli has clocked over 17,000 hours of working and has treated 550,000 kilo litres of wastewater at a negligible cost of just two rupees per 1000 litres. It has discharged more than 400 million litres of clean treated water into the water body. “It is very important to use technology that is appropriate, decentralised and sustainable in executing projects for the environment, especially pertaining to waste water and solid waste”, said Pravinjith, MD, Ecoparadigm Technologies.

This case study shows that other than active citizenry and funding, it is the adoption of the right technology that is crucial. The rehabilitation and rejuvenation of Kundalahalli Lake won the National Water Award for the year 2018 under the best Residents’ Welfare Association (RWA) category. These annual awards were instituted by the Union Ministry of Water Resources, River Development and Ganga Rejuvenation, and included a citation, memento and a cash prize of INR 2 lakhs. The project was selected from among 3,400 entries for adopting an innovative concept to treat sewage to a high degree of purity and permitting clean water to replenish the lake. The award was conferred at a function in New Delhi by Hon’ble Minister Nitin Gadkari in February 2019.

Says Arvind Keerthy, urban environmentalist and member of the Brookefield Residents’ Association: “When we took up the challenge of rejuvenating the Kundalahalli Lake, we needed a nearly unbreakable treatment system with nearly zero maintenance cost. Ecoparadigm successfully solved this challenge with the DTS technology.” Pravinjith said: “We have to adopt appropriate technology in dealing with our civic issues. The National Award for the project was the result of a collective effort and an example of how teamwork pays off. The Brookfield Residents’ Welfare Association’s effort in initiating this project and selecting this technology paved the way for sustainable rejuvenation. We also thank all the BBMP officials who gave us all the support”.

– Sangeeta Venkatesh