The enterprise bureau inside the prefectural government of Okinawa disclosed on its website before May 20 the results of its surveys on perfluorohexane sulfonate (PFHxS) found in the water source of the Chatan water treatment facility as well as treated water there. In the latest survey conducted on April 22, the highest concentration of PFHxS was detected in water sampled from Dakujaku River, which runs to the northeast of U.S. Air Force’s Kadena Air Base, at 150 nanograms per liter. The PFHxS level found in treated water was 10 nanograms per liter.
The enterprise bureau analyzes untreated water at the Chantan water treatment facility, treated water there and water sources at five locations to ensure water quality. The second highest PFHxS concentration was found in water from the Hjia River water intake facility at 46 nanograms per liter followed by a well in Kadena at 26 nanograms per liter. (Abridged)