Water testing is relatively cheap when considering the consequences. Well water testing should be done annually, usually in the Spring, but anytime is fine. Many homes in and around the Knoxville and Tri-Cities area have their own water wells. While well water can be among the highest quality water in the world, sometimes it is not fit to drink, even though it looks and tastes pure. Older homes on City Water should be tested as well. Remember, any piping system can be contaminated. Regardless of the water source, I highly recommend getting a water test.