It's never pleasant to learn your new "neighbor" is going to be a huge industrial complex - in this case a hydro plant - especially if it's being constructed on what you thought was a protected naturalized area. Making matters worse is the fact that the Oak Ridges Moraine is a watershed and aquifer providing drinking water to ~250,000 people. And for those folks in the area relying on private wells, it has been a real shock as they are also finding out that their wells have tested positive for coliforms and e.coli. And that is unfortunate. What is unclear in this report from the Sunday Star (December 20, 2015) is whether the wells had previously been tested.
According to the Ontario ministry, owners of private wells should be "formally testing the quality of the water at least 3 times a year". Testing can alert well owners to needed maintenance; providing the opportunity to act against the factors in their control. One such choice is to install a continuous disinfection system like UV to protect their drinking water 24/7. It doesn't relieve you of the responsibility of well upkeep nor the threat of external land-use changes, but it does provide peace of mind. Learn more about UV or contact a water treatment professional in your area for more information.