The Hawaii Department of Health today said trace levels of Perfluorooctanesulfonic acid – or PFOS — were recently detected in water samples collected from the Kipapa Acres water system in Central Oahu.

The system near Waipio serves approximately 50 individuals.

Health officials say the system continues to be in full compliance with all federal and state standards for drinking water. However, the PFOS levels are above new, interim advisory levels set by the U.S. Environmental Protection Agency, and potentially pose a health risk over a lifetime of consumption.

“The trace levels of these chemicals in the Kipapa Acres system are small and do not pose an acute public health threat,” said DOH in a news release. “However, long-term consumption of drinking water with PFOS could pose health risks. While no action is necessary for users at this time, those concerned may use a home filtration option to reduce PFAS.”

PFOS is part of a large group of synthetic chemicals commonly referred to as polyfluoroalkyl substances (PFAS) — used to make a variety of consumer products more resistant to stains, grease, soil, and water, according to the EPA.

Until 2000, they were used extensively in consumer products such as carpets, paper and cardboard food packaging, and non-stick cookware. They are also a component of fire-fighting foam and have many industrial uses.

In June, the EPA proposed an interim health advisory level for PFOS of 0.00002 micrograms per liter — much lower than the prior one at 0.070 micrograms per liter — to avoid human health risks based on a lifetime of consuming water containing that level of contaminant. This new advisory level is undergoing further evaluation, according to officials.

DOH said the PFOS level confirmed at Kipapa Acres ranged from 0.0026 micrograms per liter to 0.0034 micrograms per liter, which are above the new EPA interim health advisory levels.

The Kipapa Acres water system is looking to transition to the Honolulu Board of Water Supply as its source by 2024.

“As we learn more about PFAS and possible risk to health, it remains a priority to ensure that the public is aware of these contaminants in drinking water,” said state Toxicologist Diana Felton in the release. “While these detections do not pose an acute risk to public health, we continue to work with EPA and other stakeholders to reduce PFAS exposures and establish enforceable PFAS limits that protect public health.”