Residents in Fall River are being told to watch their water for signs of oil contamination. A residential oil tank spill overnight on Thursday is thought to have leaked oil into Lake Fletcher. Anyone who gets water from the lake is being told to watch out for s strong odour or oily sheen in their water. Nova Scotia’s Department of Environment is in the process of trying to contain and clean-up the spill and say it remains unclear just how much oil may have made it’s way into the water.