Dissolved oxygen level close to zero in Mutha river

PUNE: The water tested from four points in the Mutha river shows that dissolved oxygen is close to zero in three sampling points (Mhatre bridge, Bhide bridge and Mutha-Nagzira confluence) and less than 1 ppm in Vithalwadi. There were no fishes at these sampling points, turbidity was high and there was a foul smell also. Dissolved oxygen is one of the most important indicators of the quality of water and its availability is vital for aquatic life.For good quality water, the dissolved oxygen level should be more than 5 ppm.
The tests were conducted on Thursday by four organizations - Shrishti Environment and Sustainability Society (SESS), Jalbiradari, SETU and Shristi Eco Research Institute (SERI). These organizations have jointly taken up monitoring of five rivers in the city. Scientific test kits were used to test the water.
The test results show that because of the growing population, the upstream is also getting polluted now, SERI director Sandeep Joshi told TOI. It can be attributed to absence of proper sewage and solid waste management system. "Vithalwadi to Khadakwasla is the upstream of Mutha river. Till 2008, the dissolved oxygen level was around 3 ppm to 4 ppm at Vithalwadi. At Mhatre bridge, Bhide bridge and Mutha-Nagzira confluence, it was around 1 pmm till 2008,'' he said.
Joshi said that when the rapid development of the city is taking place, instead of just giving building permissions, facilities like sewage and solid waste management should also be taken up on priority basis.
"One can find good fish biodiversity if the dissolved oxygen level is more than 5 mg per litre. But we did not see any fish at these points. Gambusia fish, which can tolerate pollution, was also not seen. The high turbidity shows that there can be possibility of pathogenic growth and sustenance in water. We saw people using the water for washing purposes and also for bathing,'' he said.
Joshi said, "Nullahs and streams carry sewage into the rivers. This lead to reduction in dissolved oxygen. In the absence of oxygen, anaerobic bacteria converts waste into methane and other gases, leading to foul smell. Now, the river has turned into nullah."
A visit to Ramnadi by these organizations found that the Ramnadi carries only sewage after the Westerly bypass culvert. The residents of Ramnagar are facing problems due to this sewage. The river bed was also encroached upon.
Suneel Joshi, convenor of NGO Jalbiradari, said that the water testing will be conducted round the year in the Ramnadi, Mula, Pavana and the Indrayani. Four locations have been identified for taking samples. This monitoring programme will be carried out on a weekly basis.Suneel Joshi pointed out that the Constitution of India's clause 51A, fundamental duties, mentions that it is the duty of every citizen to protect and improve the natural environment, including forests, lakes, rivers and wildlife, and to have compassion for living creatures. Thus, citizens should come forward and join in this monitoring programme.SESS was recently registered as a society to provide technical support to the programme. This seven-member society comprises of experts in water, education and environment. Around 30 schools will be roped in for the project, along with experts who will be taking samples from rivers and testing the quality round the year. After water is tested from all rivers, a report will be prepared and will be made available to the public, he added.BOX
Monitoring schedule
Dec 21 Ramnadi Bangalore bypass culvert, Ramnagar, Pashan lake overflow and Baner Road bridge
Dec 21 Mula Aundh, Harris bridge, Holkar bridge and Kalyaninagar
Dec 22 Pavana Ravet upstream, Morya Gosavi Mandir, Rahatani bridge, before Mula confluence
Dec 23 Indrayani Talegaon- Induri bridge, Talawade, Moshi and Alandi