The zero liquid discharge (ZLD) project of common effluent treatment plants (CETPs) in Vaniyambadi bristles with problems concerning evaporators, according to an official of the Tamil Nadu Pollution Control Board (TNPCB).

He was responding to a question raised by R. Ramasamy, a farmer of Vadasery village near Ambur on the “apathy” of the TNPCB to the continued contamination of groundwater in the Palar river owing to discharge of inadequately treated effluents by the CETPs at the monthly agriculturists' grievance day meeting at the Collectorate here on Friday. The TNPCB official said two out of the four CETPs in Vaniyambadi are implementing the ZLD project in their plants using reverse osmosis (RO) technology. As they have been facing problems in ZLD, they have installed some imported equipment to tide over the problem. The system would be in place within a month, he said.

Mr. Ramasamy said if RO plants are installed, the CETPs should recycle effluents and ensure that they are fully used by the member tanneries within their premises and that not a drop of effluent is let out. To this, the TNPCB official said that 50 per cent of RO-treated effluents are used by tanneries for their processes, while the remaining is allowed to be evaporated. But, as there is some problem with evaporators, the CETPs have installed foreign equipment.

Ajay Yadav, Collector of Vellore, who presided over the meeting, said the present evaporation technology was not good to achieve total evaporation. This problem was there even in the treatment plants for dyeing industries in Tirupur, he said.