The Army is committed to ensuring quality drinking water is provided to its Soldiers, family members, and civilians.  Proactive sampling is performed by the Army on its drinking water systems and coordination with other purveyors of drinking water to installations occurs to ensure PFOS/PFOA remains below 70 parts per trillion (ppt) for PFOS and PFOA (individually or combined). While not an enforceable regulatory standard, this represents a concentration in drinking water that is not expected to produce adverse health effects if the water is consumed over an entire lifetime.

Status: Finished drinking water, which is the treated water people drink at Sierra Army Depot, does not contain PFOS/PFOA above the EPA health advisory levels. Additionally, Army-provided drinking water complies with the standards of the Safe Drinking Water Act, a federal law designed to protect the quality of drinking water supplied to the American public. The Army will continue to sample and monitor on-installation drinking water to ensure the EPA lifetime health advisory levels or a properly promulgated state safe drinking water standard are not exceeded.

PFOA + PFOS Results:  below laboratory's ability to detect

Test results date: August 2023

Testing Frequency:  semiannually

Future Testing Event: March 2024

History: As a proactive measure in 2017, the Army tested the wells that supply the treated drinking water system at Sierra Army Depot for PFAS. One of the three wells that make up the system had a test result (150 ppt) that exceeded the EPA life time health advisory. The well was immediately removed from service. A treatment system to remove PFOS and PFOA was installed on the drinking water system. When CA regulatory authorization is provided to operate the treatment system, the well will be brought back into service. Drinking water testing results have been below the EPA lifetime health advisory since the well was shut down.  

Type of drinking water systems: Army-owned

For questions contact:  Public Affairs

Office phone number:  (530) 827-4343

Office e-mail address:  douglas.l.magill.civ@army.mil

Water Quality Reports


The Army follows the federal cleanup law, the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 (also known as “Superfund”), and long-standing Environmental Protection Agency (EPA) regulations for all chemicals in its cleanup program, including PFAS.  In collaboration with federal and state regulatory agencies and interested stakeholders, the Army follows the CERCLA process to investigate a release resulting from Army activities and to assess the appropriate cleanup actions based on risk to human health and the environment.

When the Army identifies that it has impacted drinking water above the EPA’s 2016 health advisory levels for PFOS/PFOA on or off an installation, it takes appropriate actions to provide alternate water and ensure drinking water levels are promptly reduced below the health advisory levels (for example, by providing bottled water, shutting down wells, installing treatment systems or connecting to municipal water).

Final reports, points of contact, and/or site specific web links will be updated on this page as cleanup actions progress.

CERCLA is a complex, multi-phase process that provides a consistent, science-based approach across the nation for cleanup and may take years to complete. Read more about CERCLA and the phased approach here


Current CERCLA Phase:  Remedial Investigation underway



For more information, contact:  Public Affairs

Office phone number: (530) 827-4343

Office e-mail address:   douglas.l.magill.civ@army.mil