Pune: The Pimpri Chinchwad Municipal Corporation’s annual environment status report stated that Pavana, Indrayani and Mula rivers , passing through its areas, were heavily polluted because of discharge of untreated domestic and industrial effluents. The environment status report (ESR) report said the quality of water in these rivers was not suitable for aquatic life, since the average dissolved oxygen in them is below 4 mg/l. It could lead to incidents like mass fish deaths — as has been reported in Indrayani and Pavana rivers in the past.
Chemical tests revealed that Pavana river is more polluted because it passes through the heart of the city and 65 nullahs flow into it. Industrial effluent is the likely reason for contamination of Indrayani since it flows through industrial areas and is the second most polluted river after Pavana. Nine nullahs flow into Mula and 12 into Indrayani, the report said.
A total of 408 MLD of sewage is generated within Pimpri Chinchwad limits and 364 MLD is treated. Pimpri Chinchwad Municipal Corporation ( PCMC ) regularly tests water samples from the three rivers. The average chemical oxygen demand in these rivers in all seasons is below 4 mg/l, which is not safe for survival of some fish species.
“Big fish need more dissolved oxygen; hence their survival chances are low. Besides, there are bunds at many places along the rivers, because of which they cannot migrate and die,” Kiran Ghotkule, expert on the Indrayani ecosystem, told TOI. He.