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U.S. Military Accountability for PFAS Contamination on Bases in Okinawa

Craig Thomas Donovan


  • Discusses the U.S. Marine Corps release of approximately 64,000 liters of wastewater with a potentially dangerous chemical into the municipal sewer system in Okinawa, Japan.
  • Addresses the Marines lack of accountability leading to Japan bearing the cost of the removal and disposal of 360,000 liters of wastewater.
  • Notes that Japan SOFA should require that U.S. military assessments of on-base environmental damage, remediation plans, and records be publicly available.
U.S. Military Accountability for PFAS Contamination on Bases in Okinawa
e-kamakura via Getty Images

On August 26, 2021, the U.S. Marine Corps (Marines) Air Station Futenma (MCAS Futenma), located in Ginowan City on Japan’s Okinawa main island, released approximately 64,000 liters of wastewater with a potentially dangerous chemical into the municipal sewer system. The wastewater contained spilled fire-fighting foam stored on the base. The foam contained perfluorooctane sulfonic acid (PFOS), a compound that belongs to a chemical family known as per- and polyfluoroalkyl substances (PFAS). The decision to release the wastewater was virtually unexpected by Okinawa prefectural and Japanese central government authorities. The U.S. Marines had informed authorities only 25 minutes before the release occurred, assuring that the PFOS was treated and at a safe level. Initially, the United States and Japan had planned to discuss test results of treated wastewater sampled from the base and the wastewater's safe disposal later that same day.

When the authorities requested entry to MCAS Futenma to confirm the water's PFOS level, the Marines denied the request. The authorities took water samples from a manhole outside the base shortly after. They found a combined concentration of PFOS and another PFAS compound (PFOA) measuring 0.67 µg/L, which was 13 times higher than Japan's national safe drinking water threshold (0.05 µg/L). Residents living around MCAS Futenma have protested, and Okinawa authorities have objected to the Marines' actions. Japan only has national water quality safety guidelines for PFOS levels in rivers and drinking water, but no safety standards for PFAS discharged into sewers. Because of the high levels of PFAS detected on or near MCAS Futenma and other bases, Okinawans and U.S. military personnel now face a grave concern that the U.S. military's storage and use of fire-fighting foam have contaminated Okinawa's drinking water and the environment. 

PFAS comprise more than 4,000 synthetic chemicals used in industry and consumer products in the United States and worldwide for more than 70 years. In the late 1960s, the U.S. military's use of PFAS increased, following a catastrophic fire on the aircraft carrier, U.S.S. Forrestal. Soon after, the U.S. military and industry developed a PFAS-containing aqueous film-forming foam (AFFF) that could successfully extinguish large petroleum and flammable-liquid fires. The Pentagon deployed AFFF on U.S. military ships, fuel storage areas, and bases at home and abroad.

PFAS can enter the environment and migrate during their production and use. They commonly seep into groundwater that becomes drinking water through improper AFFF storage and uses at airports and military bases, wastewater processing that produces biosolids applied to farmland as fertilizer, discharge and runoff of industrial waste, and consumer products discarded in unlined landfills. PFAS also persist in the environment. Human and animal exposure may occur through accumulation in the food chain. Researchers have found PFAS in agricultural plants and the tissues and organs of farm animals, pets, and other terrestrial and aquatic organisms in and around Japan like the Japanese sparrowhawk (Accipiter gularis) and Dall’s porpoise (Phocoenoides dalli). Although more research is needed to conclusively link PFAS to adverse health effects in humans and animals, studies have shown that PFOS and PFOA may lead to a high risk of cancer, liver and kidney disease, reproductive and developmental damage, and other medical disorders.

News of Okinawa main island's PFAS contamination began in 2016 when Okinawa authorities measured elevated PFAS levels in water samples taken from rivers and streams running through another U.S. base, the Kadena Air Base. Okinawa authorities conducted several follow-up tests that repeatedly showed high levels of PFAS in waterways, soil, and drinking water provided to the island’s residents. Tests near MCAS Futenma also indicated that wells and springs had high levels of PFAS. Moreover, in 2019, Kyoto University researchers conducted blood tests of residents living around MCAS Futenma. The PFOS concentration in residents' blood was four times the national average, at 13.9 nanograms per milliliter (ng/mL). These surveys strongly indicated that two significant sources of PFAS contamination were MCAS Futenma and the Kadena Air Base. Investigators concluded that Okinawans became exposed to PFAS contamination through three pathways: on-base fire-fighting training, accidental spills of AFFF, and improper disposal of AFFF. The U.S. military generally does not grant Okinawa and Japanese authorities' requests for on-base access to conduct investigations and denies responsibility for any contamination.

Inequities and Structural Weaknesses in Japan SOFA

Post-WWII history and the U.S. military's current status in Okinawa Prefecture are critical to understanding why the U.S. military lacks environmental accountability and generally refuses Japanese and Okinawa authorities access to its bases when PFAS contamination occurs. In April 1945, the last major battle of WWII began with the U.S. attack on Okinawa main island. The Japanese surrendered the island 82 days later, and the U.S. military’s occupation of Okinawa Prefecture started. After the war ended on August 15, 1945, the U.S. military formally occupied mainland Japan until April 1952. From 1952 until the present, the United States has maintained a significant military presence in Okinawa Prefecture. There are 32 U.S. military bases including one USFJ-JSDF joint base on Okinawa main island and its vicinity. Okinawa Prefecture constitutes approximately 70.6 percent of the land used for U.S. bases in Japan, and hosts approximately 26,000 active U.S. military personnel.

In 1951, the United States signed the Treaty of Peace with Japan. This treaty allowed Japan to retain the title but gave the United States total administrative, legislative, and jurisdictional control over Okinawa Prefecture. In 1972, the United States returned Okinawa Prefecture to Japanese sovereignty. Okinawa Prefecture was made subject to the 1960 U.S.-Japan Security Treaty and other agreements that continued U.S. military base operations and defense of Japan. 

One such agreement was the 1960 U.S.-Japan Status of Forces Agreement (Japan SOFA). Japan SOFA establishes the legal rights and obligations of the U.S. military and its civilian components stationed in Japan. Japan SOFA allows the United States to control military base access and refuse inspection requests by Japanese authorities. It provides that, “[w]ithin the facilities and areas, the [U.S.] may take all the measures necessary for their establishment, operation, safeguarding, and control." Id. Japan SOFA also exempts the U.S. military from any obligation to remediate environmental damage on former military installations returned to Japanese civilian use or fund the cost of remediation. It states that, “[t]he [U.S.] is not obliged, when it returns facilities and areas to Japan on the expiration of this Agreement or at an earlier date, to restore the facilities and areas to the condition in which they were at the time they became available to the [U.S.] armed forces, or to compensate Japan in lieu of such restoration." In addition, based on a vague legal standard, Japan SOFA releases active U.S. service members from liability and compensation claims for actions committed in the performance of an "official duty" that cause Japanese property damage.

Moreover, Japan SOFA establishes the U.S.-Japan Joint Committee (Joint Committee) to handle daily U.S. military base issues in Japan. The Joint Committee interprets the SOFA and determines the Japan Environmental Governing Standards (JEGS) concerning environmental protocols on U.S. military bases. It is a self-regulating body and makes decisions without public disclosure and scrutiny. In 2015, the United States and Japan signed a clarification to SOFA called Cooperation Concerning Environmental Matters. This clarification gave Japan the right to request access to military bases to observe the U.S. military's actions in addressing a spill or before returning land to Japan and conduct sampling together with the U.S. military. Approval, however, rests within the broad discretion of the local base commander, Commander U.S. Forces in Japan (COMUSJAPAN), or a designee, who may deny the request if it would "interrupt military operations, compromise force protection, or hinder the management of the facilities and areas.” If approved, any observations or sampling must not "interfere with the actions of the [U.S. military] in addressing the spill or with other operations."

Some Recommendations for a New Path Forward

Two recent developments have occurred concerning MCAS Futenma's August 26 wastewater release. On September 10, 2021, the Marines replaced the AFFF supply containing PFOS and PFOA at MCAS Futenma and other bases in Okinawa Prefecture with a safer, more environmentally friendly alternative. The Marines, however, have not disclosed the chemical ingredients of the replacement foam to the public. The United States and Japan also announced that the Japanese Ministry of Defense would remove and dispose of the remaining 360,000 liters of wastewater containing used fire-fighting foam stored at MCAS Futenma. Japan will bear the removal and disposal, costing about 92 million yen ($836,000).

Although these may be positive signs of how seriously the United States and Japan are now treating Okinawa Prefecture’s PFAS contamination, the U.S. military's lack of environmental accountability and transparency and denial of access to its bases remain. Therefore, a new path forward is needed. The United States and Japan should renegotiate a more equitable and balanced Japan SOFA that incorporates international environmental law norms like the "polluter pays principle" and no transboundary environmental harm to other states. The U.S. military should remediate past and present environmental damage that it has caused on or around its former bases before returning them to Japanese civilian use and bear the costs of evaluating and remediating this environmental damage or compensating Japan instead of restoration. The U.S. military should also provide Japan with a legal right of access to bases for observation and investigation, and consult and coordinate with Japanese and local authorities before conducting on-base remediation.

Moreover, U.S. service members whose acts cause damage to Japanese property should be held accountable. Japan SOFA should contain a clear definition of performance of official duty and include a stringent legal standard for exemption of liability and compensation claims. The U.S. military should also prove by clear and convincing evidence that service members' actions that cause damage to Japanese property satisfy this legal standard and provide Japan with a legal right to review the evidence and respond. 

Furthermore, Okinawa main island has a dense residential population living around MCAS Futenma and other bases. Japan SOFA should grant Japan the legal right to promptly enter U.S. bases without advance notice for investigation when a significant spill or contamination emergency occurs that cannot be contained within a base's boundaries or threatens local Japanese drinking water. Japan SOFA should require that U.S. military assessments of on-base environmental damage, remediation plans, and records be publicly available and provide an opportunity for local authority and public review, so long as these do not compromise classified information or genuine U.S.-Japan security interests. Such reforms would be a good start toward repairing the U.S. military's fractured relationship with the Okinawans and restoring confidence in U.S. environmental leadership internationally.