bws logo black and white

For Immediate Release
April 26, 2023

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

HONOLULU –   The Board of Water Supply (BWS) has confirmed the low-level detection of various perfluoroalkyl substances (PFAS) at its Kaamilo Wells Pumping Station.  The type of PFAS chemicals and the levels detected are 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 well station is located in Aiea and serves the area from Pali Momi Street to Halawa District Park. 

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