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Unreported Yokota air base spills raise questions on US Forces Japan transparency

The around 800 pages of documents provided by the U.S. government after a freedom of information request are seen on June 21, 2019, in Chiyoda Ward, Tokyo. (Mainichi/Emi Naito)
(Mainichi)

TOKYO -- The 131 unreported fuel and other chemical spill incidents discovered by the Mainichi Shimbun at the U.S. Air Force's Yokota base in western Tokyo have raised serious questions about what exactly has been going on out of sight from nearby residents and the Japanese government.

The Mainichi Shimbun discovered the spills that occurred over an eight-year period up to 2017 through some 800 pages of documents obtained through a freedom of information request filed with the U.S. government. The documents plus responses to enquiries to the base's 374th Airlift Wing Public Affairs Office revealed that in February 2012, grass surrounding fuel tanks had been found to have changed color. A subsequent investigation found that some 734 gallons of diesel fuel, approximately 2,770 liters, had leaked due to tank corrosion and deterioration.

In August the same year, a fuel and water mixture was being discharged from a tank into an oil and water separator by base personnel when some of the fuel ended up in the sanitation system. Some living quarters on the base then filled with fumes, causing the evacuation of the occupants.

In the documents obtained by the Mainichi, comments in a spill report on its possible effects read: "It is possible that 5-20 gallons of JP-8 flowed off base via the sanitary sewer system to the Fussa City WWTP (Wastewater Treatment Plant). Off-base effects are unknown at present."

In September 2016, fuel leaked from a C-130 Hercules military transport aircraft in mid-flight. The report describing the spill reads, "The plane had 40 kilopounds (about 18,000 kilograms) of fuel upon take off. During flight, fuel could be seen gushing from the left wing. A lot of fuel was lost in-flight. Upon landing, the plane had 20 kilopounds (around 9,000 kilograms) of fuel and continued leaking." The report also states the flight, which was originally headed for Guam, was cut short upon discovery of the leak.

Leakage incidents over the period haven't been confined to fuel. In August 2014, a report indicates that material containing asbestos may have been disposed of off-base by a contractor.

In released documents relating to the 2012 diesel spill, under the section asking if there was a "Potential Environmental / Off-base Impact" the "Yes" field is filled in. In response to enquiries from the Mainichi Shimbun, the base's public affairs department stated that a separate report was "the most accurate report on the 734 diesel fuel spill," adding that, "After a thorough assessment, CE (Civil Engineer Squadron) determined the spill had no impact to the surrounding communities or on base residents."

Despite requests for further clarification, the public affairs department did not provide a clear explanation on why the spill had originally been deemed to have had potential effects on the environment or off-base.

Regarding the 2014 asbestos disposal, the base responded, "The investigation did not determine if ACM (asbestos-containing material) was disposed of off-base by a local national contractor, but all ACM identified by base personnel was disposed of properly by an environmental contract as a result of the investigation."

This photo disclosed to the Mainichi Shimbun shows a fuel spill at the U.S. forces' Yokota Air Base in the suburbs of Tokyo in November 2015. According to internal documents of the forces dated on the day of the accident, 30 to 50 gallons of unidentified mixture including oil seeped from a pile of iron scraps near a tarmac and maintenance area. The spilled substances flowed into drains, but there were no signs of them leaking off the base, according to the documents. Another internal document dated eight days after the accident identifies the spilled material as some 30 gallons of operating fluid.

When it came to the 2016 mid-flight fuel spill from the C-130 transport plane, the base explained, "The 20K lbs of JP-8 that was lost mid-flight dissipated before reaching the ground." It also said that "an estimated 5-10 gallons of JP-8 that was spilled on the flight line was cleaned on-site with absorbents. No fuel reached soil or drainage system."

In 1997, the Japanese and U.S. governments agreed on a notification system for events and accidents at the time they occur based on the possibility that the cases may be harmful to the environment. The agreement covers effects from dangerous items, harmful items, the misuse, disposal or leakage of radioactive materials, and other chemical discharges.

The Japan Environmental Governing Standards (JEGS), a set of guidelines detailing the U.S. military's rules on managing dangerous materials in Japan, also includes provisions for reporting leaks. But the rules it sets down on conveying information are unclear.

Regarding Petroleum, Oil & Lubricants (POL), JEGS state that amounts "in excess of 400 liters (110 gallons)" constitute a "significant spill." Regarding the mandated response to a significant spill, it reads: "When a significant spill occurs inside a DoD (Department of Defense) installation and cannot be contained within the installation boundaries or threatens the local Japanese drinking water resource, off-base population or property ... the appropriate GoJ (Government of Japan) authorities will be notified immediately."

However, in three incidents that did not exceed the amounts prescribed by JEGS, including the approximately 10 gallons of jet fuel that leaked in July 2010, Japanese authorities were informed. Conversely, in what appears to be an inconsistent response, the spillage of some 734 gallons of diesel was not reported.

An individual connected to Japan's diplomatic services said, "JEGS has been established by the U.S. military, so we can't say that Japan has a right to interpret the guidelines." Yoshiyuki Yoichi, a former head of the Japanese Ministry of Defense environmental policy office chimed with this view, saying, "JEGS are internal U.S. military rules, which Japan has no right to inspect. It can't be discounted that the interpretation of what 'threatens the off-base population' may come down to an arbitrary decision by U.S. forces."

When a liaison council made up of six municipal authorities around Yokota base and the Tokyo Metropolitan Government received reports of the incident in which approximately 100 gallons of jet fuel leaked from a C-130 military transport plane in March 2017, it responded by saying it wanted any subsequent similar incidents to be conveyed quickly. But five months on, when a similar case saw around 100 gallons leaked, no reports were made to the liaison council.

When asked why the base had not responded to the requests from municipal and metropolitan authorities, the base's 374th Airlift Wing Public Affairs Office said, "There was little difference between the two spills, in regards to amount spilled, contained, and cleaned up. Neither of the spills required reporting. We cannot determine exactly why GOJ was informed of the 3 March 2017 spill."

In response to questions regarding the September 2016 C-130 leak of some 9,000 kilograms of fuel, the public affairs office stated that as the plane was mid-flight and taking part in an off-installation training event, it is not required under JEGS for the incident to be reported.

(Japanese original by Tamami Kawakami, City News Department)

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