LOW LEVELS OF PFAS DETECTED IN ST. STEPHEN DIOCESAN CENTER WATER SYSTEM ON OʻAHU

Posted on Jun 3, 2025 in Newsroom
Map of St. Stephen Diocesan Center

HONOLULU — Low levels of PFAS (perfluoroalkyl and polyfluoroalkyl substances) have been detected in water samples collected at the SSDC-1 Well Chlorinator of the St. Stephen Diocesan Center water system (Public Water System HI0000314, owned by the Roman Catholic Church, Hawaiʻi) which serves a portion of Windward Oʻahu.

The detections of Perfluoroctane Sulfonic Acid (PFOS) are below the U.S. Environmental Protection Agency’s (EPA) Maximum Contaminant Level (MCL) and are unlikely to pose a public health risk.

The PFOS detections were sporadic, with concentrations ranging from non-detected to 2.7 nanogram per liter (ng/L), which is below the EPA MCL for PFOS of 4.0 ng/L. MCLs are the highest levels of contaminants that are allowed in drinking water by the EPA.

PFAS ChemicalSample Collection DateDetected Level (ng/L)Maximum Contaminant Level (MCL) (ng/L)
Perfluoroctane Sulfonic Acid (PFOS)July 18, 20232.24.0
Perfluoroctane Sulfonic Acid (PFOS)Oct. 4, 2023Non-Detected4.0
Perfluoroctane Sulfonic Acid (PFOS)April 21, 20252.64.0
Perfluoroctane Sulfonic Acid (PFOS)May 19, 20252.74.0

The water system formally notified the Hawaiʻi Department of Health (DOH) of the initial detection of PFOS via email on May 29, 2025. According to the EPA, PFAS, which have been used since the 1940s, are fluorinated organic chemicals that have been used extensively in consumer products such as carpets, clothing, fabrics for furniture, paper packaging for food and other materials (e.g., cookware) designed to be waterproof, stain-resistant, or non-stick. They are also a component of firefighting foam and have many industrial uses.

For more information on PFAS, please see https://www.epa.gov/pfas or https://health.hawaii.gov/pfas. Impacted users may also contact St. Stephen Diocesan Center water system.

This press release is issued in accordance with Hawaii Revised Statutes (HRS) § 340E-24(b).


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News Release – Low Levels of PFAS Detected in St. Stephen’s Diocesan Center Water System on Oʻahu