Although test results received on Aug. 8 showed minute amounts of perfluorinated compounds, or PFCs, in Wells 7 and 8, Sammamish Plateau Water assures customers that its water is perfectly safe to consume.

According to the test, which was taken July 27, Well No. 7 contains 0.015 parts per billion of perfluorooctane sulfonate (PFOS); this matched the level of PFOS found at Well No. 7 during a June 15 test.

The newest test also showed 0.029 parts per billion of PFOS 350 feet away at Well No. 8, which had never before had any problems, according to Operations Manager Scott Jonas.

Both wells are far below the Environmental Protection Agency’s advisory level of 0.07 parts per billion of PFOS and perfluorooctanoic acid (PFOA) combined, meaning that the water is absolutely harmless to drink. There were no PFOAs found at all in the water.

However, Jonas said that the water district will continue to perform rigorous testing because “we want to find out where this stuff is coming from.”

The answer may not lie too far away; Wells 7 and 8 share an aquifer with the city of Issaquah, which has been having its own problems with PFCs this year.

After the EPA sent out its new PFC advisory levels in January, Issaquah turned off its Gilman Well No. 4, which was found to have PFCs last year. The PFC levels detected at Well No. 4 were much higher than those found in Sammamish; testing done June 13 showed 0.6 parts per billion of PFOS in unfiltered water.

To fix the issue, the city of Issaquah installed a filtration system that cost $658,000 in 2016 alone. The system, which Jonas applauded as a “very proactive approach” to the problem, has been doing the job; filtered water at Well No. 4 showed no detectable amounts of PFCs in the June 13 test, and the well is back up and running.

Meanwhile, June 28 test results showed 0.0294 parts per billion of PFOS at Issaquah’s Gilman Well No. 5, which shares a pump house with Well No. 4.

As this is below the EPA’s health advisory level and actual detection level, Well No. 5 is still running, city of Issaquah Communications Coordinator Warren Kagarise said in an email. However, the water is being “further diluted with Well No. 4 [filtered] water.”

“Stringent testing has been conducted — even below levels defined by the EPA as an actual detection — to better understand the potential sources of PFCs,” Kagarise stated.

Issaquah tested Sammamish’s monitoring Well No. 7.3 back in May to try to figure out the source of the contamination. Though only 0.019 parts per billion of PFOS were found at the monitoring well, which is 45 feet away from Well No. 7, Jonas said that the water district “thought it was prudent to check” the other wells for PFCs after that.

PFCs are not regulated chemicals, but Jonas explained that the EPA routinely puts out lists of unregulated chemicals to check for.

“New chemicals are being released into the environment — the EPA wants to see if they’re making it into the water system,” Jonas said. After all, he went on, “30 years ago people didn’t think asbestos was harmful.”

PFCs are used in the production of fire suppressants, Teflon and waterproof clothing like Gore-Tex. In high amounts they have been linked to a variety of health issues, such as cancer, thyroid problems, a weakened immune system, high cholesterol and pregnancy complications such as preeclampsia. Jonas said that around 90 percent of people have tiny amounts of PFCs in their system.

“These chemicals weren’t created to be in the environment,” Jonas said. “It’s a nasty chemcial — that’s why we take it seriously.”

Sammamish Plateau Water will continue working with its consultants, Corona Environmental Consulting and CDM Smith, to actively monitor the water for PFCs. This is standard practice for the water district, which normally takes about 900 samples per year.

“[PFCs] are not regulated, but that doesn’t mean we don’t need to do our due diligence,” Jonas said. “We want to know what the levels are … and in order to do that we need to sample on a routine basis. We will be sampling aggressively.”

And as with the latest Well No. 8 findings, Sammamish Plateau Water will continue to make the public aware of any toxins, no matter how small an amount.

“If we were to find anything, we’d be forthright and honest,” Jonas said. “We try to be open and transparent.”