Drinking Water Quality

Irvine Ranch Water District (IRWD) is the local water provider for central Orange County, serving all of Irvine and portions of Newport Beach, Costa Mesa, Tustin, Orange, Lake Forest, and unincorporated areas.

Drinking Water Safety

Irvine’s drinking water is safe. It meets all of the exacting standards set by the state and federal governments. California’s drinking water standards are among the most stringent in the nation and, in many cases, are more demanding and therefore supersede federal requirements.

IRWD and its regional water suppliers frequently go beyond what is required by these federal and state regulatory agencies — monitoring Irvine’s water from source to tap for regulated and unregulated elements. IRWD also maintains a state-certified water quality laboratory in Irvine that annually performs over a quarter of a million tests on its water supply to ensure high quality.

IRWD releases a Water Quality Report by July 1 every year, informing customers about the quality of their drinking water. View the latest report and learn more information at IRWD.com/quality.

Water Sources & Reliability

IRWD is innovative with its water supply and is fortunate not to be dependent upon only one source of water.

  • 65% of Irvine’s drinking water comes from local groundwater wells managed by IRWD and the Orange County Water District (OCWD).

  • 35% comes from imported water from the Colorado River via the State Water Project and Colorado River Aqueduct.

Having access to local water keeps the cost of water lower for Irvine residents and businesses and significantly increases the overall reliability and resiliency of Irvine’s water supply. For more information on water resiliency, visit the IRWD website.

Recycled Water

Recycled water is not used for drinking water or other uses inside homes and businesses, but it significantly reduces Irvine’s dependence on imported water.

About 28% of the water needs of IRWD’s service area are met using recycled water, primarily for landscape and agricultural irrigation. Doing so extends the drinking water supply — because every gallon of recycled water saves a gallon of drinking water.

For more information on IRWD’s use of recycled water, visit IRWD.com/recycledwater.

Water History in Irvine

El Toro Groundwater Remediation Facility

In 1985, trichloroethylene (TCE) was found in portions of the groundwater basin beneath the former Marine Corps Air Station El Toro (now the Great Park) and portions of central Irvine. TCE is a volatile organic compound that was widely used as a solvent for aircraft cleaning.

IRWD, OCWD, and the United States Department of the Navy have completed a joint project, the El Toro Groundwater Remediation Project, to clean up the TCE plume.

Regular testing of water from IRWD’s 27 drinking water wells has never detected TCE in drinking water served to customers. There are no drinking water wells in the TCE plume emanating from the former Marine Corps Air Station El Toro. In March 2009, the U.S. EPA determined that no "potential vapor intrusion problems" exist in Irvine neighborhoods.

For more information on the El Toro Groundwater Remediation Facility, visit the IRWD website.

Irvine Desalter Project
In the late 1980s, it was discovered that portions of the groundwater beneath Irvine have high salt levels because of the natural geology of the area and the history of agricultural use.

The Irvine Desalter Plant was designed and constructed to clean the elevated levels of salt in this previously untapped local groundwater, thus adding to IRWD’s drinking water supply.

For more information on the Irvine Desalter Project, visit the IRWD website.

More Information

Learn more about City of Irvine Environmental Programs here.