Aranakigaa, a spring about a quarter-mile from Marine Corps Air Station Futenma’s southwestern fence line, is pictured in Ginowan city, Okinawa, on Aug. 1, 2024. The spring registered 1.1 micrograms of PFAS per liter, 22 times the provisional standard, according to an annual report released by the Okinawa prefecture’s Environmental Protection Division in April. (Keishi Koja/Stars and Stripes)
MARINE CORPS AIR STATION FUTENMA, Okinawa — Okinawa added four more checkpoints outside this U.S. base in its hunt for the source of PFAS in nearby wells, the prefecture announced in a meeting Wednesday.
The prefecture began digging the checkpoints last week between MCAS Futenma and wells registering high levels of PFAS contamination, a spokesman for the prefecture’s Environmental Protection Division said by phone Thursday. The prefecture announced the additional checkpoints at a meeting of PFAS experts on Wednesday in Naha.
The checkpoints — part of a three-year project to find the source of PFAS contamination in the affected wells — may be finished in August or September, the spokesman said. Eight checkpoints — four per year — were dug in 2022 and 2023, he added.
“I think we will be able to get data by around October and hope we can show it in November when the next meeting will happen,” the spokesman said.
Some Japanese government officials are required to speak to the media only on condition of anonymity.
“We still think that contaminated groundwater is accumulated or exists under MCAS Futenma and this is flowing to these wells,” the spokesman said.
Researchers at two Okinawa universities also discovered PFOS — a component of PFAS — at levels 82 times Japan’s national average in porcupinefish caught in a canal where groundwater from MCAS Futenma flows, according to a Thursday report by Okinawa Times.
Japan’s Ministry of the Environment surveys the level of chemical substances in living organisms each fiscal year.
Professor Yutaka Tashiro of Meio University, who conducted the study with associate professor Takuma Ito of Okinawa International University, could not be reached by email Thursday. The report was not available online.
PFAS and its components, PFOS and PFOA, are found in firefighting aqueous film forming foam, once commonly used on some U.S. military bases. They are also found in a wide variety of consumer products, including nonstick cookware and stain-resistant clothing and fabrics.
In April 2020, 38,000 gallons of firefighting foam spilled into a stream and neighborhood near MCAS Futenma.
The Defense Department has removed the firefighting foam from all its Navy and Marine Corps bases in Japan and from all Army bases and Misawa Air Base on Honshu, the largest of the country’s four main islands, U.S. Forces Japan said in June 2023.
The U.S. Environmental Protection Agency dubbed PFAS and its components “forever chemicals” because they persist a long time in the environment. They pose a potential danger to the body’s immune system and may be linked to kidney and testicular cancer, low birth weight and lower anti-body response to vaccines, according to the Centers for Disease Control and Prevention.
The prefecture’s Environmental Protection Division discovered PFAS above Japan’s provisional safe drinking water standard in 19 of 37 sites it sampled around MCAS Futenma between August 2023 and January, according to an annual report released by the division in April. Japan’s provisional standard is 0.05 micrograms per liter.
