TWO Common Ef fluent Treatment plants (CETPs), 86 dyeing and washing units attached to these CETPs and an Individual Effluent Treatment Plant (IETP) were closed down by the Tirupur branch of the Tamil Nadu Pollution Control Board (TNPCB) on Wednesday, as the units were found to be discharging effluents into the Noyyal river. Based on complaints, a team of TNPCB officials, led by District Environmental Engineer R Kannan, conducted surprise raids at the CETPs at Veerapandi and Arulpuram on Tuesday. The team found that the CETPs and the dyeing units had not implemented the proper treatment systems for achieving zero liquid discharge, thus violating TNPCB norms regarding the same. Taking action on the issue, the Tirupur branch of the TNPCB closed down all the 86 dyeing and washing units attached to the two CETPs and the IETP. The electricity connections to the units were also snapped.