Mahestala Nangi Wastewater Treatment Plant, Maheshtala, West Bengal

Mahestala Nangi is a wastewater treatment plant located in Batanagar, Maheshtala, within the Kolkata Metropolitan Area in West Bengal, India. The plant was designed to serve a population of 26,725, classifying it as a medium-sized agglomeration under Indian urban wastewater management standards. Under India's regulatory framework, wastewater treatment plants are governed by the Water (Prevention and Control of Pollution) Act, 1974, and the Environment Protection Act, 1986. The Central Pollution Control Board (CPCB) and the West Bengal Pollution Control Board (WBPCB) set discharge standards. For plants of this scale, secondary treatment is typically required, with tertiary treatment in sensitive areas. The designed capacity of 1.00 million liters per day indicates the intended scale of operations. The plant's treated effluent would have discharged into local water bodies within the Hooghly River basin, which flows into the Bay of Bengal. The Hooghly River is a distributary of the Ganges, supporting diverse aquatic life and providing water for agriculture and domestic use. The Kolkata Metropolitan Area faces challenges from industrial and domestic pollution, making wastewater treatment critical for protecting downstream ecosystems and public health.

The plant is located in the Hooghly River basin, part of the Ganges delta system. The Hooghly River flows south into the Bay of Bengal, supporting a rich estuarine ecosystem. The area is ecologically sensitive due to the Sundarbans mangrove forest downstream, which is a critical habitat for the Bengal tiger and other species. Proper wastewater treatment is essential to prevent nutrient and pathogen pollution that could harm this fragile environment.