Pune: The civic body’s environment status report for 2023 indicated that Mutha river was extremely polluted, much more than Mula-Mutha. The environment status report (ESR) is based on sample analysis of water from the rivers in the city. It said the biochemical oxygen demand (BOD) and chemical oxygen demand (COD) in the Mutha exceeded the Central Pollution Control Board’s (CPCB) standards.
The CPCB BOD standard is 30mg/l and COD standard is 150mg/l. The Pune Municipal Corporation (PMC) collected samples from six locations across the river, finding the stretch near Mhatre Bridge highly contaminated. BOD is the amount of oxygen consumed by bacteria or microorganisms as they break down the organic matter (like sewage content) present in the water, thus decreasing the level of oxygen and leading to production of various compounds, some harmful.
It also leads to death of aquatic life and presence of water hyacinth. COD is the amount of oxygen needed to dissolve the chemical organic matter (industrial effluents). In all, the ESR studied six locations in Mutha river, eight in Mula-Mutha river, indicators in Pavana and Katraj Lake as well as Ambil, Nagzari and Bhairoba nullahs.
Out of all the locations, the Mutha river showed the highest level of contamination. PMC environment officer Mangesh Dighe told TOI, “Mutha river is very clean before it enters the city limits. However, the many nullahs carrying untreated sewage into the river within city limits contaminate Mutha.
The JI.