Kolhapur: The newly constructed sewage treatment plant (STP) at KasbaBawada needs to be upgraded, to treat waste water effectively, according to the draft of the Environment Status Report (ESR).

The task to compile the report was given to a private firm by the Kolhapur Municipal Corporation (KMC).

The report enlists events related to environmental protection in the last two years and status of facilities set up to conserve the city's environmental heritage. The report goes on to suggest ways to improve the environmental quality of the city.

The report was presented to the city level monitoring committee (CLMC) on Monday. The firm has been asked to re-draft the report and submit the final report in the next eight days.

As per senior officials, the report claims that the biological oxygen demand (BOD) of the treated waste water is much higher, which means the waste water is not being treated properly.

A senior KMC official, requesting anonymity, said, "The BOD of the waste water treated by the STP is around 10.2 mg/L. It is much higher than normal levels. Hence, the water is not suitable to be released into the river. We are yet to conclude as to why STP is functioning in such a way. These are only the preliminary findings. The variation in BOD levels is due to changes in season. We have asked the firm to study details of water sample test analysis, available with the Maharashtra Pollution Control Board (MPCB) in order to arrive at a conclusion."

Officials agree that the waste water pumped from Jayanthi nullah is only being treated in the primary stages, which means removal of contaminants in the advanced stages is not taking place.

The waste water is settled in tanks at the STP. After most of the sediments settle at the bottom, the mostly clear liquid is treated with chemicals and then released into the river. The report claims that though most of the pollutants settle down at the bottom of the tank, dissolving harmful chemicals into the water leads to an increase in the BOD.

The members of CLMC have asked the firm to submit a plan of action for air and water pollution in the city. The report needs to be compiled before being made public. The firm has been asked to suggest measures for proper functioning of the bio-diversity board, that was set up recently, said the official.