Water quality is required by state and federal regulations to be monitored; Fairfax Water Authority took 13,000 samples over last year to come up with their quality tables that they have released into their nine page yearly report. If you’re curious how safe our water is you should give it a read; the short answer is: very safe. Northern Virginia probably has some of the safest water in the world provided to the 1.7 million customers.
Water comes from either the Potomac or the Occoquan rivers, goes through coagulation, flocculation, sedimentation (which leaves cleaner water), ozonation (which kills bacteria), filtration (removes care products and pharmaceuticals), and then goes through fluoridation and chlorination before being delivered to your home.
Some people may be sensitive to the minute amounts of chlorine added to the water, an average of 2.6ppm (parts per million) in 2012, which might mean a water conditioning system would be worth considering, but for most households they simply won’t provide much benefit.