Some Hawaii residents using bottled water due to 'forever chemicals' in wells

Around 650 Hawaii residents have been relying on bottled water since March, after the state health department detected synthetic chemicals, known as PFAS, in the local water system.

The contamination dates back to at least October, when Hawaii's Department of Health detected the chemicals in one of two wells that serve Kunia Village, an affordable housing development on O'ahu.

The department announced in January that the levels detected exceeded the Environmental Protection Agency's proposed limit for two types of PFAS — called PFOA and PFOS — in drinking water, as well as Hawaii's state limit, above which communities are expected to treat their water systems or provide an alternative source. The concentration is under the current EPA limit, however.

Kunia Village stopped using the contaminated well after that. Then in early March, the water system's operator started dispensing bottled water to residents out of concern that the second well might also be contaminated, which health department tests confirmed last week.

Residents were instructed to use bottled water for drinking or brushing teeth and tap water for washing hands, doing laundry or taking baths.

"We just felt it's important to act quickly and conservatively," said Stephanie Whalen, president of the Kunia Water Association.

PFAS stands for per- and polyfluoroalkyl substances, but they're more often referred to as "forever chemicals" because they're nearly impossible to destroy so can linger permanently in air, water and soil.

The class of chemicals is associated with health consequences, including low birth weight, high cholesterol and thyroid disease. PFOA, in particular, has been linked to an increased risk of kidney cancer. A study published last year found that exposure to high levels of PFOS was associated with an increased risk of liver cancer.

PFAS are used in the manufacturing of consumer products such as food wrappers, cosmetics and textiles because of ​​their ability to resist stains, grease and water. They're also found at some military sites due to the use of a PFAS-based firefighting foam dating back to the 1970s. The military still uses the foam to respond to emergencies but has stopped using it for testing and training.

PFAS contamination in water is widespread across the U.S. The Environmental Working Group, a research and advocacy organization focused on toxic chemicals, told NBC News that at least 1,500 sites would violate EPA's proposed PFAS limits for drinking water — 4 parts per trillion — which the agency hopes to finalize by the end of this year.

The EPA, meanwhile, said in March that up to 6,300 water systems — serving as many as 94 million people — contain levels of PFAS above its proposed limits.

"There are very few places we’ve looked for PFAS and not found them," said Jamie DeWitt, a toxicology professor at East Carolina University who reviewed the water sampling results from Kunia Village. "That's just a testament to just how pervasive they are in the environment."

But Kunia's levels are higher than the average background concentrations found across the country, according to Anna Reade, a senior scientist at the Natural Resources Defense Council, an environmental advocacy group.

"This is a pretty alarming level that they’re picking up," Reade said.

In one Kunia Village well, PFOA levels were up to double the EPA's proposed limit, and PFOS levels were up to 3.5 times higher. In the other, PFOA levels were around five to seven times higher than the proposed threshold, and PFOS levels were at least 11 times higher.

"It hits all of the marks of being too contaminated for people to drink safely," Reade said.

Hawaii's health department said it has been testing small water systems located near probable PFAS hot spots — such as industrial or military sites — with the help of grant money from the EPA.

Kunia Village is one such site, the department said, but added that it did not know how long PFAS were present in the area's water before the tests in October.

"The major concern is, people may have been consuming this for many, many years — maybe even decades," DeWitt said.

Testing for PFAS is becoming more common, though: The Safe Drinking Water Act requires large public water systems — and some medium and smaller ones — to screen for the chemicals through 2025 and report results through the following year.

The type of monitoring that Hawaii is doing is voluntary, Reade said, but over the next few years, "we will get quite a bit more information on what we’re facing in our drinking water."

Individual water systems respond to high levels of PFAS in different ways. Some provide bottled water temporarily, but Reade said that many also employ long-term solutions like connecting to a new water source or installing a specialized treatment system.

It can take a while for communities to decide on or implement such solutions, however. The town of Emmaus, Pennsylvania, for example, is still weighing its options more than a year after elevated PFAS levels were detected in its water.

The source of the contamination in Kunia Village hasn't been identified, but the health department said the PFAS compounds detected appear to match those from other sites with known contamination from firefighting foam.

DeWitt, too, said that in Kunia Village's case, "it seems as if the sources are military sources, as opposed to an industrial source or a landfill."

The health department said it is waiting on the Army, which owns one of the wells, to provide more information.

The U.S. Army Garrison Hawaii said it does not know the source of the contamination but is investigating whether PFAS-containing materials may have been stored, used or released at military sites nearby.

In April, Whalen said, Kunia Village started running water from a different source through the water line to flush out the contamination. It's waiting on results of more recent tests.

"Those results come back clean, great. We'll stop bottled water. They don't, then we continue bottled water," Whalen said.

Low levels of PFAS have been detected in several water systems in Honolulu this year as well. Reade said it's not surprising given the state's history of military activity.

"I think it will, unfortunately, be an issue that Hawaii will have to deal with beyond a few wells," she said.

Aria Bendix is the breaking health reporter for NBC News Digital.