Bhubaneshwar: As a step towards achieving environmental excellence, Tata Steel`s Sukinda Chromite Mine in the state of Odisha has set-up state-of-the-art Effluent Treatment Plant (ETP) of capacity 108 million litres/day that treats both surface run off and mine water to almost drinking water specifications. This is the biggest ETP in the region and the largest single location ETP in India.
Tata Steel operates one of India’s largest chromite mines at the Sukinda Valley in Odisha producing chrome ore which is subsequently converted it to Ferro Chrome and sold to customers across the world. A large quantity of water, generated during mining and due to rainfall, needs to be handled during the mining operations. The Sukinda Valley experiences about 110 cm to 180 cm of rainfall annually, of which 80% of the rainfall is during the monsoon season i.e. between June and September. Water coming in contact with chromium ore preferentially leaches out soluble hexavalent chromium from the ore body. As a result, water from the mine contains 0.2-4 mg/l of hexavalent chromium against a safe limit of 0.05 mg/l for human consumption; requiring all water to be treated before its release from the mines.
The ETP in Sukinda Chromite Mine has 24/7 real-time monitoring of the input raw effluent and output treated water for hexavalent chromium, pH and Total Suspended Solids through online monitors installed at both input (raw effluent) and output (treated water).The treated water in the ETP is recycled as an input to the Water Treatment Plant for drinking water purpose. This is not only resulting in water conservation but is also a step towards being water neutral.