News Releases from Department of Health

HONOLULU – Additional PFAS (perfluoroalkyl and polyfluoroalkyl substances) have been detected in water samples collected at the Waialua Sugar Pump 2 water system (Public Water System HI0000309, owned by OPU Waialua Corp.) and serves approximately 500 persons in the northwest area of the island of O‘ahu. This new detection is a result of the continuing investigation into the initial detection of PFAS in 2023, which identified different derivatives of PFAS. The 2023 news release can be viewed here.

 Additional PFAS at the Waialua Sugar Pump 2 water system were confirmed in lab reports dated Nov. 27, 2023, and Feb. 6, 2024.  The water system notified the Department of Health (DOH) of the initial detection of the 2 additional PFAS (PFHxS and PFHxA) through an email on Feb. 26, 2024.  Although there is no Maximum Contamination Level (MCL) for PFHxS, the Hazard Index based on the PFHxS detection is 0.233, which is below EPA’s proposed 1.0 compliance threshold. Currently, there is no Hazard Index nor MCL for PFHxA.

The detected levels of PFAS at the Waialua Sugar Pump 2 water system’s two wells (Well F and G) samples are listed in the table below. 

Well	PFAS Chemical	PFAS Chemical Abbreviation	Detected levels (ng/L)1	EPA Proposed MCL (ng/L)1
Well F	Perfluorohexanesulfonic acid	PFHxS	2.0- 2.2	n/a (see note 2)
	Perfluorohexanoic acid	PFHxA	2.1- 2.2	n/a
Well G	Perfluorohexanoic acid	PFHxA	2.0- 2.2	n/a

¹   ng/L = nanogram per liter = parts per trillion (ppt) 

²   This contaminant is considered in the proposed Hazard Index calculation.   

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 fire-fighting foam and have many industrial uses. 

For more information on PFAS, please see https://www.epa.gov/pfas or https://health.hawaii.gov/pfas. Users may also contact their water purveyor. 

This press release is issued in accordance with Hawaii Revised Statutes (HRS) Section 340E24(b). 

Acronyms and Definitions 

DOH – Hawaiʻi Department of Health, responsible for regulation and oversight of impacts to the environment and health of the people in Hawaiʻi.  This includes regulated drinking water systems. 

EPA – United States Environmental Protection Agency responsible for the protection of human health and the environment on a national level. 

HRS – Hawaii Revised Statutes are laws enacted by the Hawaiʻi State legislature. 

Hazard Index – A cumulative health risk to be considered when multiple compounds are present even if individual MCLs or EALs are met. The Health Index is the sum of the ratios of the respective contaminants. The proposed EPA requirement is to be less than 1.0 (unitless) to be in compliance. 

MCL – Maximum Contaminant Level, set by EPA, is the highest level of a contaminant that is allowed in drinking water. Proposed MCLs are not enforceable. On March 14, 2023, EPA issued proposed MCLs for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) and Maximum Contaminant Level Goals (MCLGs) for four additional PFAS compounds. Final MCLs are anticipated in late 2023, at which time these values would become enforceable legal limits and public water systems would be required to test for these chemicals. As of this press release, the final MCLs have not yet been published. 

PFAS – Perfluoroalkyl and Polyfluoroalkyl substances, fluorinated organic chemicals that have been used extensively since the 1940s. 

# # #