There are four rivers that flow through the Pune and Pimpri-Chinchwad municipal areas – the Mula, Mutha, Pavana and Indrayani which finally join the Bhima river. The Mula-Mutha which is considered to be a twin river is actually a combination of the Mula, Mutha and the Pavana rivers. Today, all the four rivers, across most of their lengths, are highly polluted.
The Pavana flows right through the middle of the highly industrialised Pimri-Chinchwad area consisting of more than 3000 industrial units of which about 2500 are engineering units, 250 electronics units, 100 chemical units, 25 pharmaceutical units, and ten textile and dyeing units, which are among the worst polluting industries. These units generate an estimated 50 million litres a day (MLD) of effluents which are directly discharged into the Pavana river without being treated.
The waters of the Pavana meet the Mula river downstream and finally merge into the Mutha river in Pune city where it is further polluted with about 700 MLD of untreated domestic sewage and industrial effluents. All this muck flows into the river Bhima whose waters affect the life of more than 75 villages downstream. While the Pavana mostly receives industrial effluents, the Mutha is mostly polluted by residential effluents.
The level of dissolved oxygen at various places in the these rivers is virtually zero – which means its waters cannot support any form of submerged aquatic life. The situation is worsened by the unchecked growth of water hyacinth which blocks out sunlight from penetrating the water. In 1840’s zoologists had recorded more than a 100 species of fishes in the waters of these rivers. Today, there are barely 40 species left.
Initiatives like the PMC’s River Mutha Water Quality Improvement Project have had some effect in reduction in stagnation of water in the river. But with more than one lakh cubic metres a day (CMD) of untreated effluents being released, such efforts are too little. It is the industries which will have to do more.
Municipal corporations are not doing enough. They will not only have to enforce treatment of industrial effluents, but also have to create adequate capacity to treat residential sewage.
The water became dangerous for consumption.According to the Maharashtra Pollution Control Board, organic matter in the Mutha is between 105-255 mg per litre. The permissible limit is 6 mg per litre.