PFAS detected in Consolidated Baseyards water system on Maui

Low levels of PFAS (perfluoroalkyl and polyfluoroalkyl substances) have been detected in water samples collected at the Consolidated Baseyards Wells 1 and 2 tank tap of the Consolidated Baseyards water system (Public Water System HI0000258, owned by Consolidated-Waiko Water Association, Inc.) which serves a portion of Central Maui.

The detections of the chemical Perfluorohexane Sulfonic Acid (PFHxS) are below the US Environmental Protection Agency’s (EPA) Maximum Contaminant Level (MCL) and are unlikely to pose a public health risk.

The detection of PFHxS was sporadic, with concentrations ranging from non-detected to 2.2 nanogram per liter (ng/L), which is below the EPA MCL for PFHxS of 10 ng/L. MCLs are the highest levels of contaminants that are allowed in drinking water by the EPA.

The water system formally notified the Hawaiʻi Department of Health of the initial detection of PFAS via email on May 15, 2025. Although PFAS was not detected in the October 2023 sample, the March 2025 result confirmed sporadic detections.

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 their water purveyor, Consolidated-Waiko Water Association, Inc.