City of Santa Ana PFAS Treatment at John Garthe Reservoir

The Orange County Water District (OCWD) manages the groundwater basin underlying north and central Orange County that provides 85% of the water supply to 2.5 million people. OCWD and the 19 local water suppliers it serves, such as the City of Santa Ana, provide safe and dependable drinking water that continually meets all state and federal water quality standards.

PFAS are a group of thousands of manmade chemicals that are used in a number of industrial processes and firefighting activities and to make products non-stick and/or resistant to water, oil, and stains. Produced by chemical manufacturers, these substances have been detected in parts of the Orange County Groundwater Basin. While OCWD and the City of Santa Ana are not responsible for their release into the environment, they are collaborating to ensure their removal from local water supplies.

Project Overview

Construction of a treatment facility at the City of Santa Ana’s John Garthe Reservoir, located at 2401 N. Bristol Street, will begin in Spring 2026. The new treatment facility will treat 13.8 million gallons of water per day from five existing drinking water wells (three of which are on-site). Construction consists of the installation of three pre-treatment vessels and 12 ion exchange pressure vessels, and enhancements to existing on-site wells and hydrogenerator. As part of the project, landscaping improvements and an updated frontage wall will be added along Bristol Street.

Construction Timeline

  • Date: Spring 2026 – Summer 2028
  • Hours: Monday through Friday from 8 a.m.-5 p.m. No work will be performed on weekends or holidays

Project Materials and Updates

  • Coming soon

Impacts to the Community

OCWD and the City are committed to completing this work as efficiently as possible while minimizing impacts to the surrounding community. The facility will be built entirely within the City’s John Garthe Reservoir location. However, sidewalk travel along Bristol will be limited during construction. Temporary traffic control will be in effect during this time. Bristol will remain available to vehicles and access to residences will remain open at all times. Those near the construction site may notice an increase in noise, dust and construction equipment.

Questions and Information

  • For questions about this project, please contact us
  • For information about the City of Santa Ana’s Water Resources Division, please visit the City’s website
  • For information on how OCWD is addressing PFAS in Orange County, please visit the PFAS education center