The US has rejected the request of the Japanese Defence Ministry's Okinawa Defence Bureau to access Kadena Air Base and U.S. Marine Corps Air Station Futenma, both located on the island of Okinawa, after it was found that the level of carcinogens in rivers and at water treatment facilities that surround the US military bases seriously exceeded norms, the Japanese newspaper Asahi Shimbun reported.
According to the newspaper, test sites in the vicinity of the bases have high concentrations of the compounds perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA).
READ MORE: Tokyo, Okinawa Gov'ts Agree to Start Talks on US Base Relocation — Reports
The US can issue such a rejection under the Japan-US Status of Forces Agreement (SOFA) which stipulates that the US has a right to "take all the measures necessary" for the "establishment, operation, safeguarding and control" of its facilities and areas.
Okinawa accounts for only 0.6 percent of Japan's territory but hosts 74 percent of US military facilities and more than half of all US forces deployed in Japan. According to the prefecture's administration, there are 25,800 US servicemen and 19,000 members of their families and US civilians in Okinawa.
In FY 2016, Okinawa officials spent approximately 170 million yen ($1.5 million) on measures designed to control the contamination.