Is Tap Water Safe?

Is tap water safe to drink? Is bottled water safer than tap water?

  • Testing of bottled water is less frequent than tap water.
  • The EPA regulates tap water quality.
  • Leaching of plastic in bottled water is not tested.
  • Bacteria growth during storage is not tested in bottled water.
  • Municipal water agencies are required to conduct extensive regular water quality testing by certified laboratories.

Following recent reports of nationwide scandals involving water quality, Americans continue to question the safety of their tap water provided by municipal sources. We use tap water to wash the dishes, water our lawns, share with our pets and most importantly we drink it. While some Southern Californians drink tap water, others prefer bottled water and continue to ask whether Southern California tap water is safe?

The Food and Drug Administration (FDA) is responsible for monitoring the safety of bottled water, while public tap water is regulated by the U.S. Environmental Protection Agency (EPA). The difference in the regulation processes between the two vary greatly. In California, bottled water must be tested and meet the same limits as potable water, but testing is much less frequent and is performed only on samples at the bottling plant. This would not detect any leaching of plastic components from bottles or bacteria that might grow during storage.


Potable water systems, which include drinking water, monitor and conduct testing throughout the pipelines delivering water to customers. Bottled water is required to report test results only if requested, while public water systems must provide water quality results each year to their customers.

In comparison, because of the Safe Drinking Water Act, municipal water agencies are required to conduct extensive regular water quality testing by certified laboratories. Furthermore, public water agencies are required to provide customers with annual water quality reports. Customers can easily access reports on the local water supply by reviewing information on their water agency’s website; bottled water companies are not required to do the same.

“Drinking water is carefully regulated with oversight in California by the State Water Resources Control Board Division of Drinking Water (DDW).  Testing is performed at a minimum daily, weekly, monthly, quarterly, annually, and triennially for a wide variety of constituents including all Maximum Concentration Limits (MCL) to ensure safe water is delivered to customers,” shares Brenda Meyer, Western Municipal Water District Principal Engineer.  “Water system operators also carefully monitor various parameters during treatment and delivery to ensure the source water is effectively and reliably treated to drinking water standards.”

Ms. Meyer is responsible for reviewing all required data to ensure MCLs are met and later reports the data to the DDW.  She and her staff are required to submit various monthly, quarterly, and annual reports proving the water agency’s continual delivery of safe drinking water.  She also monitors for trends of various constituents to ensure there is sufficient warning to continue to meet water quality standards in the future. Constituents are organic and inorganic matter found in water, in the liquid form.


“Two things come to mind that I believe make people doubt tap water quality.  The first is the ‘bad’ news, such as the water quality crisis in Flint.  This type of news is somewhat like a product recall, but instead of targeting the specific area of impact the entire potable (drinking) water industry becomes suspect,” continues Ms. Meyer.  “There are thousands and thousands of potable water systems that continually and consistently deliver safe water, but doubt is cast on all if one system has problems. The second item is the advertising done by bottle water producers.  To me, there is an implied message that only bottled water is pure and therefore, water from the tap must be bad.”

As Californian’s continue to be curious about the quality of their drinking water, their interest can take them on a journey to learn more about their public water sources and safety. The key to making informed decisions is to research and learn about how their tap water is treated and tested. A simple look at a water quality report can answer several questions concerning water quality.