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For Immediate Release
March 31, 2023

Board of Water Supply Confirms Low Level Detection of PFAS at Halawa Wells Pumping Station

HONOLULU –   The Board of Water Supply (BWS) has confirmed the low-level detection of various perfluoroalkyl substances (PFAS) at its Halawa Wells Pumping Station.   The type of PFAS chemicals and the levels detected is shown in the table below.   The BWS reported the findings to the Hawaii Department of Health (DOH) in accordance with Hawaii State Law.

On March 14, 2023, the U.S. Environmental Protection Agency (EPA) issued proposed National Primary Drinking Water Regulation maximum contaminant levels (MCLs) for Perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic acid (PFOS).  In addition, EPA also proposed a Hazard Index to determine the combined risk of four specific PFAS chemicals in drinking water at a site.  The Hazard Index is calculated by summing the ratios of each detected compound relative to its Health-Based Water Concentration.  The table below shows the PFAS detected and its amount in relation to EPA’s proposed standard and existing DOH environmental action levels (EALs)

According to DOH the amount of PFOS and PFOA detected are above EPA’s interim lifetime health advisory of 0.02 ppt and 0.004 ppt respectively which could indicate a potential health risk over a lifetime of drinking water with these levels of the chemicals.  DOH has advised that those concerned may use a home filtration option to reduce these PFAS chemicals.  Based on existing DOH environmental action levels and no exceedance with EPA’s proposed Hazard Index for the remaining PFAS chemicals detected, there is no significant health concern.

BWS detected these chemicals as part of its PFAS testing program.  Multiple samples were tested to confirm the finding and improvements in test methods and technology enables the detection of these very low levels.  The Halawa Wells Pumping Station was shut down on 12/8/21 in response to the Red Hill contamination crisis.  It continues to remain shut down and not serving any water to the system.  The well station is located in Halawa Heights on Aliipoe Drive.  BWS previously detected PFOA and PFHxS in August 2020 and reported the findings to DOH at that time.  DOH then issued a press release in October 2020.

PFAS 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 also have been used in fire-retarding foam.

Manager and Chief Engineer Ernest Lau stated, “We take our kuleana to provide safe drinking water to our community seriously and will continue to test for PFAS chemicals and monitor for any changes.”


Kathleen Elliott-Pahinui
Information Officer
Honolulu Board of Water Supply
Phone: (808) 292-4672