Is Mission Viejo Tap Water Safe to Drink?

Yes, tap water is drinkable.

Tap Safe includes data from many publicly available sources, including the WHO (World Health Organization), CDC (Center for Disease Control), and user submitted databases, but unfortunately there's not enough data about Mission Viejo.

To see user submitted ratings of the water quality for California, see the "User Submitted Ratings" box on this page.

Yes, Mission Viejo’s tap water is generally considered safe to drink as it met the EPA’s water quality mandates in its 2020 Water Quality Report. From April 1, 2018 to June 30, 2021 Mission Viejo’s Moulton Niguel Water District has had no Safe Drinking Water Act Violation. One should not get sick from drinking Mission Viejo tap water. 

Though Mission Viejo’s tap water is generally safe to drink, one should consider the possible safety impacts of low levels of regulated contaminants, unregulated contaminants, and water quality issues caused by severe weather.

While Mission Viejo’s tap water is generally safe to drink, long-term residents may consider using water filters for their everyday drinking, as the EPA is still assessing the health impacts of long-term exposure to certain contaminants that they do not yet have regulations for, and long term exposure to certain contaminants which are already regulated, but below the currently acceptable levels. 

Where Does Mission Viejo Tap Water Come From?

According to Mission Viejo’s 2020 Water Quality Report, Moulton Niguel Water District obtains water for its customers from the city aquifer:

Here in the Moulton Niguel Water District, our water is imported from Northern California and the Colorado River. Water from Northern California travels to us through a complex delivery system known as the California State Water Project. Designed and built in the 1960s, the State Water Project is one of the most significant public water and power utilities globally, providing drinking water for more than 27 million people statewide. 

The project is managed by the California Department of Water Resources (DWR). The project stretches over 700 miles, from Lake Oroville in the north to Lake Perris in the south. Water stored in Lake Oroville, Folsom Lake, and other tributaries, fed by snowmelt from the Sierra Mountains, flows into the Sacramento and San Joaquin rivers and reservoirs in the Bay-Delta region. Giant pumps lift the water into the 444-mile-long California Aqueduct from the Bay-Delta, flowing southward to cities and farms in central and Southern California. Composed mainly of concrete-lined canals, the Aqueduct also includes over 20 miles of tunnels and nearly 160 miles of pipelines. Along the way, the water is pumped 2,882 feet over the Tehachapi Mountains. The Edmonston Pumping Plant alone lifts millions of gallons a day up 1,926 feet, the highest single water lift in the world.

Main Contaminants Found in Mission Viejo Tap Water

As we mentioned above, Mission Viejo tap water meets the requirements set by the EPA. For more precise information please see their 2020 Water Quality Report. Though Mission Viejo drinking water meets EPA standards that does not mean it is contaminant free as there are levels that the EPA considers acceptable. Though the EPA regulated contaminants must meet a certain threshold for the city’s water to be deemed acceptable, many are still present in the drinking water at some level. The EPA continues to evaluate the long term impacts of these chemicals as more research is available. For example, the rules around arsenic, as well as, lead and copper are currently being re-evaluated.

Additionally, there are a number of “emerging” contaminants that the EPA has not determined acceptable levels for and is currently researching. For example, Per- and polyfluoroalkyl substances (PFAS), for which the EPA has issued a health advisory. PFAS are also called ‘forever chemicals’ since they tend not to break down in the environment or the human body and can accumulate over time. We do not yet fully understand the dangers of PFAS as they are currently being investigated. We do not have any information on PFAS in Mission Viejo’s drink water, so there may be a risk of contamination.

Lead piping is another potential source of contamination for many homes, both through service lines and in your home. The National Resource Defense Council has a great walk-through on how to determine if you may have lead service lines.

So while Mission Viejo’s tap water does meet the requirements set by the EPA, it still makes sense to try to purify the tap water further to reduce contaminants to lower levels.