The Defense Ministry announced that its estimate of the overall cost of constructing a replacement facility for a U.S. military base in Okinawa Prefecture will nearly triple to 930 billion yen ($8.48 billion) and take much longer than expected.

The government blamed the delay and cost overrun for the reclamation work in coastal Henoko in Nago on the need to solidify a vast expanse of soft seabed at the site.

Details of a new estimate for the project, all funded by Japanese taxpayers, were presented Dec. 25 when specialists met to advise on the reinforcement work for the Defense Ministry.

The facility will replace the U.S. Marine Corps Air Station Futenma in Ginowan city.

The new cost projection is about 2.7 times higher than the central government’s initial estimate five years earlier. It was the first time that the overall cost, including the strengthening work, has been presented to the public by the central government.

Revised projections call for the work to take 12 years--four more than initially planned--after Okinawa prefectural authorities sign off on the central government’s application for design change in the reclamation work.

The central government must still gain approval for the design change to proceed with reclamation work on the northeastern side of Henoko point, where poor subsoil has been discovered.

Reclaiming offshore land on the southwestern side began in 2018.

The Futenma airfield, located in the middle of a densely populated residential area, is being relocated because it is considered to pose a threat to residents.

Okinawans had long clamored for early closure of the Futenma facility and for Tokyo to find an alternative site outside the prefecture.

In 2014, Defense Minister Itsunori Onodera estimated that at least 350 billion yen would be needed to complete the project.

The Defense Ministry was alerted to the poor subsoil, which was described as having the “consistency of mayonnaise,” through surveys by 2016, but only disclosed the matter in 2018.

In 2013, the central government’s estimate for the reclamation work was 231 billion yen.

The figure then jumped to 722.5 billion yen due to the additional work to shore up the weak ground.

The land reclamation, including the reinforcement work, is expected to take nine years and three months to finish, while construction of a V-shaped airstrip and related facilities will take about three years, bringing the total to 12 years or so.

When Tokyo and Washington agreed in 2013 on the timetable for returning the land occupied by the Futenma base, officials envisaged a handover date of fiscal 2022 at the earliest.

But the new estimate shows this will now be postponed to the mid-2030s, delivering a blow to residents of Ginowan exposed to the deafening noise of aircraft taking off and who live in fear of an accident occurring.

“I was shocked” by the central government’s announcement, said Kenei Yamashiro, 81, who heads a group of plaintiffs in a lawsuit seeking compensation for noise pollution from the Futenma airfield, on Dec. 25.

Yamashiro, who lives in the neighborhood of Futenma, said, “The announcement means that nothing will be done about the danger of Futenma while I am alive.”

The central government is expected to apply for the design change in the reclamation work involving the soft seabed by the end of March.

But Okinawa Governor Denny Tamaki, a staunch opponent of the base project, will almost certainly never agree. It might be the last card he can play to block further construction work.

In November 2018, the prefectural government projected that the overall cost will total around 2.5 trillion yen and take 13 years to complete.

Prefectural officials also contend it is technically impossible to solidify the weak seabed with the technology currently available in Japan.

Vessels engaged in reclamation work can operate to a depth of about 70 meters from the sea surface, according to experts. The depth of the sea is 30 meters on the northeastern side of Henoko. The weak surface extends to a depth of 60 meters, totaling 90 meters from the surface.

Tamaki questioned the soundness of embarking on project that is deemed technically dubious and financed entirely by taxpayer money.

The central government’s new estimate for the overall cost came after a government official expressed a preference that the price tag be kept within the threshold of 1 trillion yen.

Okinawa's Vice Governor Kiichiro Jahana blasted the revised estimate on Dec. 25.

The central government has pitched the project to build a new U.S. military facility in Okinawa Prefecture, citing Futenma base’s precarious location. It also maintains there is no viable alternative site even though the southernmost prefecture hosts around 70 percent of all U.S. military facilities in Japan.

The revised schedule means that Ginowan's residents will have to put up with the threat posed by the Futenma airfield for at least 10 more years, probably longer.

“The central government's goal of removing the threat around Futenma as soon as possible is now falling apart,” Jahana said.

Hideko Yamada, a 65-year-old Nago resident who joins a daily sit-in near the U.S. Marine Corps Camp Schwab, was perplexed about the wisdom of flinging such a vast amount of public funds at a project whose feasibility and completion are not guaranteed.

“We want our country to spend money on you and your children, not a U.S. military base,” she said to a young member of the riot police who was present during the protest.

(This article was compiled from reports by Ryuichi Yamashita, Ryo Aibara, Kazuyuki Ito, Ryutaro Abe, Takahiro Takenouchi and Shinichi Fujiwara.)