CHENNAI, April 22:Declining to extend the time given for setting up common effluent treatment plants, the Madras High Court has ordered the closure of 434 dyeing and bleaching units in Karur, following their failure to check effluent discharge from their units.It might be recalled that a writ petition was filed by the National Trust for Clean Environment seeking action against dyeing and bleaching units in Karur for not taking steps in accordance with the pollution control law.