Water quality is an important issue that should not be taken lightly.
As for safety, many people throughout the country have no qualms about drinking tap water due to regular testing and monitoring by government agencies to ensure it is safe. Drinking water can reasonably be expected to contain at least small amounts of some contaminants. As long as those contaminants are at levels no higher than EPA standards, the water is considered safe to drink for healthy people.
But numerous consumers still seek cleaner, better tasting water, as evidenced by the $11 billion spent on bottled water last year. And because of recent reports that some bottled water supplies come from municipal water - not pristine water sources as promoted - coupled with questions about the safety of the plastic used in many water bottles and their environmental impact, consumers are left wondering what other options exist.
While filtration is an individual decision, the first step is educating your self. A quick online search can help ease concern and steer homeowners in the right direction.
Environmental Protection Agency: http://www.epa.gov/epahome/whereyoulive.htm
Water Quality Association: http://www.wqa.org/consumer/enter.cfm