The U.S. Environmental Protection Agency is rolling out a new plan aimed at stopping the spread of groundwater contamination in one of Orange County’s most critical drinking water sources and is asking the public to weigh in before it moves forward.

The proposed interim cleanup plan targets the most heavily impacted portions of the Orange County North Basin Superfund site, which stretches beneath parts of Anaheim, Fullerton, and Buena Park. The area sits within the larger Orange County Groundwater Basin, which supplies about 85% of the drinking water for central Orange County.

The contamination traces back to past industrial activity that polluted roughly 6.4 square miles of the basin, with pollutants found as deep as 500 feet underground. Because of the risk, six drinking water wells in Anaheim and Fullerton were taken offline to ensure residents continue receiving water that meets state and federal safety standards.

EPA’s proposal focuses on containing and treating the polluted groundwater before it can spread further or reach additional supply wells. The plan calls for installing about 17 extraction wells to pull contaminated water out of the ground, routing it to a centralized treatment facility, and then sending the cleaned water back underground through another 17 injection wells. Long-term monitoring would track contamination levels, while restrictions would limit groundwater use in the most affected areas.

If implemented, the system is designed not only to protect wells currently in service but potentially allow some of the shut-down wells to safely return to operation in the future.

The agency has opened a public comment period on the proposal through February 19, 2026, and will host a public meeting on January 29 to walk through the plan and answer questions. Meeting materials and a recorded presentation are available on the project’s website.

The Orange County North Basin site was added to EPA’s National Priorities List in 2020, placing it among the nation’s most complex hazardous waste cleanup locations under the federal Superfund program.

For communities that rely heavily on groundwater, the proposal represents a significant step toward long-term protection of a resource that sits out of sight but remains essential to daily life in Orange County.