Is filtered water safer than tap water?

Safety Concerns with Filtered Water

Not all water supplies are alike; to filter effectively, you need to know what contaminants come out of your faucet.
Not all water supplies are alike; to filter effectively, you need to know what contaminants come out of your faucet.

Setting up a filtering system at home isn't an automatic tap-water fix. It's a potentially good idea that requires certain steps to implement properly. Without those steps, the system can be ineffective or, worse, detrimental.

The first consideration is your specific tap water. Not all water supplies are alike -- far from it. To implement a useful home filtering system, you need to know what you're trying to filter out. A point-of-entry aerator won't be of any use if you're aiming to eliminate bacteria.


It's easy enough to find out what's in your water if you use the city utility system, which provides water-testing results to its customers every year in the required Consumer Confidence Report. If you haven't received one, you can call your water company and request it.

If you get your water from a private well or you want to be sure the water coming out of your faucet is OK (if you've got an old house with lead pipes, for instance), you can do your own testing. The U.S. Environmental Protection Agency or EPA's Safe Drinking Water Hotline can recommend companies in your area.

There are two more issues to be aware of when it comes to filtered water. First, look for an NSF-certified filter so you know it's doing what it claims. The National Sanitation Foundation, or NSF, tests water-safety products and determines whether they meet national and international standards and live up to their claims.

Finally, and this is a big one, make sure you maintain the filter the way the manufacturer recommends, especially in terms of periodic replacement. If a filter gets overly clogged with contaminants and you just keep running water through it, those contaminants can leak into the water, leaving you with more dangerous water than you started with.

As with any precautionary action, it's best to start from a position of knowledge. Especially before investing in a whole-house system, find out what's in your water, what you want to remove, and how best to do it for your particular situation. Smartly implemented, a filtering system can be an effective and cost-efficient water-safety measure.

For more information on filtered water, water safety and related topics, look over the links below.

Related Articles


  • Boyles, Salynn. "Many Tap Water Filters Work Well." WebMD. April 9, 2007.
  • Consumer Guide to Water Filters. NRDC.
  • Different Water Filtration Methods Explained. APEC.
  • Ingham, Barbara. "Tap Water, Bottled Water, Filtered Water: Which to Choose?" University of Wisconsin.
  • Water Health Series: Filtration Facts. EPA.