Over the last five months, Isabelle Couture has become accustomed to boiling pots of water on her stove, buying 18-litre jugs, and brushing her teeth with a water bottle. "I haven't felt very safe to drink it, because I don't know exactly what's going on," she said. She doesn't know what harmful substances have been detected — or when it will be safe to consume water again directly from the tap.