Is My Tap Water Safe?

Medically Reviewed by Dan Brennan, MD on August 24, 2021
4 min read

You drink the tap water in your home every day, but is it safe? All water contains some minerals and contaminants, but water is only safe to drink within certain established levels.

When you consider the safety of drinking water, tap and bottled water are comparable. The Food and Drug Administration (FDA) manages the standards for drinking water to ensure that it meets safety standards. The Environmental Protection Agency (EPA) does the same thing for tap water.‌

The EPA provides consumers with information about water in their geographic area, including:

  • Water source‌
  • Contaminant levels
  • Potential health risks‌

Keep in mind that if you rely on well water, the EPA doesn’t oversee your water quality. Instead, you should conduct your own water quality tests at least once a year to ensure contaminants are within safe limits.

In addition to contaminants, your water also contains minerals. Neither water type is better for you, but hard water that contains high mineral levels may pose some health risks. You may have a preference based on how hard and soft water tastes to you.

Sources estimate that 85% of water sources in the U.S. are hard. Because there are some stigmas around hard water, many people install water softeners to reduce the mineral content of tap water.

You can tell if your water is hard or soft by measuring the calcium and magnesium content

  • Water is soft if it has 17 parts calcium and magnesium per million or less
  • Water is slightly hard if it has 17 to 60 parts per million
  • Water is moderately hard if it has 60 to 120 parts per million
  • Water is hard if it has 120 to 180 parts per million
  • Water is very hard if it has more than 180 parts per million ‌‌

Your body needs minerals like calcium and magnesium to stay healthy, but too much of a good thing can be dangerous. Some studies show links between hard water and an increased risk of some health conditions like cardiovascular disease.

Just because your water is hard does not mean it's contaminated. The EPA classifies contaminants as:

  • Physical – particles you can see in the water, like soil from a river or lake
  • Chemical – pesticides, metals, toxins, and drugs
  • Biological – bacteria, viruses, parasites, and other living organisms
  • Radiological – similar to chemicals, these elements are unbalanced based on the number of protons and neutrons they have. 

U.S. water systems that serve 100,000 or more households are required to provide annual online water quality reports. You can visit the EPA website to access the report for your water system. When you find the report, find the summary section that identifies any contaminant levels that are higher than acceptable cutoffs.‌

You can read about health risks associated with each contaminant. Your water service provider should have a plan in place for addressing any contaminants that fall outside of the acceptable range. They should also list suggestions for things you can do on your own to address the contaminants in your tap water. If you have questions about the report or your tap water quality, contact your water supplier or call the EPA directly.

If you live in an area with fewer than 100,000 households or you rely on well water, you may want to conduct your own water quality test. If you live in a home built before 1986, it’s a good idea to test your tap water separately from the water quality tests your provider conducts. This is because homes built before 1986 may contain lead pipes, increasing the contamination in your water compared to newer homes in your area.‌

You can purchase a tap water testing kit or ask your water supplier to provide one. However, the EPA recommends using a certified lab for the most accurate results. Plan to spend between $20 and $150 on your test kit. If you use a certified lab, there may be a waiting period for your results.

If you aren’t comfortable with the level of contaminants in your tap water, invest in a water filter. Reverse osmosis filters are the most effective because they remove a wide variety of contaminants, but they can cost $1,000 or more. They're also very large and may take up a lot of room under your sink or require your plumbing to be reworked.‌

A carbon filter may improve the taste of your water, but it won’t remove all of the lead. You can ensure you purchase a high-quality filter by reading the label to see if it follows standards established by the American National Standards Institute (ANSI) or NSF International. You can also look for an indication that the filter is certified by one of four labs:

  • NSF International 
  • The CSA Group
  • Underwriters Laboratories (UL)‌
  • The Water Quality Association (WQA)