TNPCB asked to set up reverse osmosis plants

Vellore: The Tamil Nadu Pollution Control Board (TNPCB) has given an ultimatum to all the 10 common effluent treatment plants (CETPs) for tanneries in the district to set up reverse osmosis (RO) plants before September 30.This is to meet the norms fixed by the TNPCB for treatment of total dissolved solids (TDS) and chloride in their effluents, according to K. Kamaraj, District Environmental Engineer (DEE), TNPCB, Vellore.

Delivering a special address at a lecture on "Environmental Pollution" under the auspices of the Indian Institute of Public Administration (IIPA), Vellore District, here on Tuesday, Mr. Kamaraj said that out of the 601 tanneries, only 495 were functioning.The remaining 106 having been closed as per Supreme Court orders for not commissioning effluent treatment plants or not joining CETPs. Ten CETPs have been established in the district with Central and State subsidies and the contribution from the tanneries.

The DEE said that even after treatment, the CETPs had been able to meet the norms fixed by the TNPCB only in respect of 34 out of the 36 parameters.The CETPs were unable to meet the TNPCB standards in respect of TDS and chloride. The TNPCB has stipulated that the TDS should be brought down to 2,100 mg per litre. When various tannery associations challenged in the Supreme Court the norm on the grounds that such norms were not fixed in any other State, the apex court upheld the TNPCB norm. Mr. Kamaraj said that after the court judgement, the TNPCB had taken steps to ensure that the CETPs conformed to the TDS norm. The TDS level could be brought down to 2,100 mg/litre only by two methods, one is solar evaporation, and the other is reverse osmosis.

Since the solar evaporation method was not found feasible for CETPs, which handled large quantities of effluents daily, the reverse osmosis method was found feasible. After the TNPCB had a dialogue with the various tannery associations in the district, the latter had agreed to install RO plants in all the CETPs. Based on the assurance given by the tanneries, the TNPCB has fixed the deadline of September 30.The TNPCB official said that each RO plant would cost Rs.10 crore. The CETP in Vaniyambadi has approached the TNPCB for help to establish the plant.