The #1 thing to do if you have a private well
If you have a private well, test it for arsenic. The ministry of health or ministry of environment in your province or territory can tell you how to do this. If your arsenic level is above 0.01 milligrams per litre (0.01 mg/L) or 10 micrograms per litre (10 µg/L), stop drinking from the well and take steps to reduce the level of arsenic. You can get information about reducing the arsenic levels in residential water treatment systems from Health Canada.
If your water is contaminated with arsenic, you may have to use bottled water until the arsenic problem is fixed.