North and South Basin groundwater cleanup projects
Protecting Orange County’s valuable local water supply
The Orange County Water District ensures the water it provides meets or exceeds state and federal drinking water standards. It implements a proactive groundwater monitoring and surface water program to protect the quality of the Orange County Groundwater Basin, which it manages.
Industrial chemicals have impacted an area in the North Basin (near Fullerton, Anaheim and Placentia) and the South Basin (near Santa Ana, Tustin and Irvine) of the Orange County Groundwater Basin that supplies two-thirds of the drinking water for more than 2.5 million people in north and central Orange County. Plumes created by past manufacturing are spreading and threaten to impact the basin. Five water wells have already been removed from service. The Orange County Water District is proactively seeking ways to clean up the pollution in a united effort with local and national regulatory agencies. The initial cleanup efforts are focused on cutting off and preventing the spread of contamination before it travels further into the main aquifer supplying hundreds of potable supply wells.
OCWD is committed to working with the community to solve threats to groundwater. Together, we can ensure a clean and reliable water supply, protect ratepayers and protect long-term property values. Information including presentations, reports, studies, press releases, and other related data will be updated regularly on this website. To submit questions or comments, please Contact Us.

North Basin
The Orange County North Basin Superfund Site focuses on a six-and-a-half-square-mile portion of the groundwater aquifer located under Fullerton, Anaheim and Placentia.

South Basin
The South Basin Groundwater Remedial Investigation and Feasibility Study focuses on a two-square-mile portion of the groundwater aquifer located under Irvine, Santa Ana and Tustin.