Several residents of Ottaparai Panchayat staged a demonstration in front of Chennimalai Bus Stand on Thursday demanding closure of dyeing and bleaching units in their village. Effluent The protesters complained that the nearly 10 polluting units illegally diverted untreated effluent into the village tank causing contamination of ground water and urged the Tamil Nadu Pollution Control Board to seal the units with immediate effect. The protest that had the participation of welfare organisations was led by Ottaparai Panchayat vice-president Thangavel and members from various residents’ associations.