Okhla Pase IV Wastewater Treatment Plant, Delhi, India

Okhla Pase IV is a major wastewater treatment facility located in the Jasola area of South East Delhi, India. It serves a population of over 1.1 million, classifying it as a large-scale treatment plant within the Delhi urban agglomeration. The plant is operational and plays a critical role in managing the city's wastewater. As a large plant in India, it is subject to the Central Pollution Control Board (CPCB) standards, which mandate secondary treatment for municipal wastewater. Plants of this scale typically employ biological treatment methods such as activated sludge or sequencing batch reactors to meet discharge norms. The treated effluent from Okhla Pase IV is discharged into the Yamuna River system, which flows through Delhi and eventually joins the Ganges. The Yamuna is heavily impacted by urban and industrial pollution, making effective treatment essential for downstream water quality and ecosystem health. The plant contributes to reducing the pollutant load entering this critical river system.

The plant discharges into the Yamuna River, a major tributary of the Ganges. The Yamuna downstream of Delhi receives significant urban and industrial wastewater, leading to high nutrient and pathogen loads. Effective treatment at Okhla Pase IV helps mitigate eutrophication and health risks in the river, which supports diverse aquatic life and is used for irrigation and drinking water supply.