Stoneridge Well PFAS Treatment System Project


In a continuing effort to supply the Tri-Valley with safe, reliable water that surpasses state and federal drinking water standards, Zone 7 is implementing a water treatment system to address Per- and Polyfluoroalkyl substances (PFAS) found in the local groundwater at the Stoneridge Well.

Existing facility
With the proposed treatment facility
  • The purpose of the project is to add necessary water treatment facilities to the existing Stoneridge Well to remove PFAS from the well’s groundwater supply.
  • Construction is taking place at Zone 7’s Stoneridge Well, located at 3750 Stoneridge Drive in Pleasanton.
  • Download our general one-sheet to get an overview of the new facility. Stoneridge Well General One-Sheet
  • Download our technical one-sheet for detailed information on the technology. Stoneridge Well Technical One-Sheet
Ion Exchange Treatment
How PFAS Removal Will Work at Stoneridge

  • At the regularly scheduled Board meeting at 7:00 p.m. on October 19, 2022, the Board approved the project.
  • Construction began on February 2, and is expected to continue through Spring 2024.
  • The treatment system is anticipated to be functional in summer 2023, and all construction is anticipated to be completed by Spring 2024.
  • Job site construction hours would be from 8 a.m. to 5 p.m., Monday through Friday. ·      
  • We do not anticipate any significant impacts to traffic or property access during project construction.


Please contact Brandon Woods at (925) 454-5078 or with any concerns. We appreciate your patience throughout the construction of this project as we make these important improvements to your water treatment system. 

Learn more about PFAS
  • All water supplied to our customers meets the regulatory standards set by the state and federal governments. 
  • In almost all cases, the quality was significantly better than required. 
  • Zone 7 continues to deliver all water below the California Division of Drinking Water’s response levels for PFOA and PFOS.
  • For more information about how we keep your water safe from PFAS click here.
  • To learn about new PFHxS advisory levels click here.