The Bangalore Water Supply and Sewerage Board (BWSSB) is implementing a novel initiative in Karnataka by employing ozonation technology to treat water at the upcoming water treatment plant situated at the TG Halli reservoir. This marks the first time such a technology is being used in the region.

The BWSSB is currently undertaking the revitalization of the TG Halli reservoir to fulfill the drinking water needs of certain areas in Bengaluru. Once a significant water source for the city during the 1970s, the reservoir had completely dried up by 2012. However, its restoration will enable the BWSSB to supply 110 MLD of water to western Bengaluru.

According to high-ranking BWSSB officials, the reason for implementing the new technology is the concern that water from the Arkavathy River, which feeds into the TG Halli reservoir, could be polluted due to nearby settlements that have cropped up over time.

BWSSB Chairperson Jayaram N. explained, “Due to the emergence of some residential areas near the Arkavathy River, we had concerns about potential contamination of the water by sewage or other pollutants. As a precautionary measure, we have opted to utilize ozonation technology.”

In addition, officials mentioned that the water quality may be negatively impacted by the flow of pollutants from the Peenya Industrial Area.

The process of ozonation involves injecting ozone (O3) into the water using high-voltage electricity, which will eliminate any bacteria or viruses present and effectively sanitize the water.

Rajiv K N, Chief Engineer at BWSSB, clarified, “Typically, we use chlorine to disinfect water. However, in this case, water from Yettinahole may already contain chlorine, and adding more chlorine is not an optimal solution. In addition, due to potential higher levels of contamination, ozonation will be employed.”

Upon completion of the ozonation process, the water will be directed through a carbon filter, which will extract any residual ozone remaining in the water.

“After passing through the carbon filter, the water will be completely free of contaminants and deemed safe for household use. Nevertheless, to prevent any pipe contamination during water distribution to residential areas, residual chlorine will be included,” Rajiv further elaborated.

Presently, only a limited number of cities such as Delhi and Nashik have implemented ozonation technology.

The revitalization project for the reservoir began in March 2019, but it has missed several deadlines, with the latest being September 2022. Officials have now stated that the project will be finished by the end of the current year.

Jayaram commented, “Most of the work has already been accomplished, including the delivery of equipment from multiple nations. We aim to complete the remaining tasks and conclude the project by the end of this year.”

High-ranking BWSSB officials cited a shortage of labor and pandemic-related issues regarding equipment import as the reasons for the delay.