Read your water reports
Plug your zip code into the Environmental Working Group's Tap Water Database https://www.ewg.org/ (This website also list information on poisons in your food and neurotoxin in hair dyes.) Or you can request a report from your local water utility. If you can't understand all the scientific terms ask your water provider to explain it, says Mark H. Weir, Ph. D., an assistant professor of environmental health sciences at The Ohio State University in Columbus.
Know your city's pipes
Especially those that serve your house. Your city water department can tell you whether you have lead service lines, but if your home was built in the late 1980s or after, the chances you have them are relatively low, says Weir.
If you do have lead pipes, run water for at least 30 second or until it's cold before drinking it to flush out liquid that's been sitting in them, doing so can reduce lead levels in water by 90 percent; drink and cook only with cold water, the metal dissolves more easily in hot water.; clean your faucet's filter screen every few months.
Filter, filter, filter
Look for a unit that gets rid of specific contaminants found in your area, and change the filter according to the manufacturer's recommendations. Expensive filtration systems will sift out everything, but may not be necessary if your water has only one or two chemicals of concern.
Test your water
You can buy at-home kits at hardware stores, but the most reliable result come from state-certified labs find on at https://www.epa.gov/ground-water-and-drinking-water which will charge you around $100.
Buy the best bottled water
According to a Natural Resources Defense Council (NRDC) report, about 25 percent of bottle water is actually tap water, which may or may not receive further treatment. A seal form NSF International signals the product has been independently tested and certified for quality.