What is the difference between tap water and filtered water?

Is tap water the same as filtered water?

No. Filtered water starts as tap water (or well water) and is then treated at home. Tap water from a public utility must meet safe drinking water standards, and the utility must tell you if it fails them, says the CDC.

Is filtered water better than tap?

Only if your water has a problem the filter fixes. CDC says to test your water first, and that you may not need a system if it has no harmful germs or chemicals. Taste, smell and appearance are not always good indicators of safety.

What do filters actually remove?

• Pitcher and fridge filters mainly improve taste and smell, and some reduce heavy metals such as lead. Most are not designed to remove germs.
• Reverse osmosis removes parasites, bacteria and viruses plus some chemicals such as lead, copper and chromium.
• UV treatment removes germs but not chemicals.

Check the label for what a product is certified to remove.

Can a filter be worse?

CDC notes filters can remove helpful substances: fluoride helps prevent cavities and chlorine kills germs. Germs can also grow in filters that are not maintained, so replace cartridges as the maker says.

What about private wells?

CDC says private well water is not regulated, treated or monitored by officials; test it at least once a year. If you have a weakened immune system, talk to your healthcare provider before choosing a filter.