A century-old ryokan traditional inn in southwestern Japan has only been changing its hot spring bathwater twice yearly, leading to legionella bacteria levels as much as 3,700 times over standard limits, local officials said Friday.

The Daimaru Besso inn in Chikushino, Fukuoka Prefecture, which says in its website that its past guests include Emperor Hirohito, posthumously known as Emperor Showa, is suspected of providing false information about the frequency of bathwater replacement. Local ordinance says such water should be changed at least once a week.

The Daimaru Besso inn in Chikushino, Fukuoka Prefecture, is pictured Feb. 24, 2023. (Kyodo)

The inn apologized on its website for causing concerns, while noting that it has resumed the operation of its main common bath since the end of December after meeting hygiene standards.

According to the Fukuoka prefectural government, the case was brought to light after legionella bacteria was found to have caused an individual, who had visited multiple locations including Daimaru Besso, to fall ill.

A local health office inspected Daimaru Besso in August, detecting in the bath area legionella bacteria levels twice those allowed under the prefectural government ordinance.

The inn at that time maintained that it was appropriately replacing water and using chlorine for disinfection. It also reported to the prefectural government in October that the bacterial levels were below the standards based on its own test.

But an inspection in November by the prefectural government came back with bacteria levels as much as 3,700 times the acceptable limits.

The inn admitted in January that it had only been changing its water on two non-business days a year, and that it had not properly been adding chlorine. Such practices had continued from around 2019.

The local government is investigating the case in light of possible violation of the Public Bath Houses Act.

Daimaru Besso's main bath is operated by circulating hot water. Under the ordinance, the whole bathwater needs to be replaced at least once a week and the residual chlorine concentration needs to be 0.4 milligram or more per liter.


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