A Guelph resident is concerned about the use of the herbicide Roundup near Guelph Lake after speaking to a worker applying the chemical in the area. Jesse Merrill explained he was driving back from dropping his son off at sailing camp for the day on Tuesday when he spotted a man spraying something on plants growing on the causeway crossing the lake. Through what Merrill termed “a very civil conversation,” he learned the chemical was Roundup and the worker was contracted by the Grand River Conservation Authority (GRCA).