Photo/Illutration The Daimaru Besso inn in Chikushino, Fukuoka Prefecture (Yoshitaka Unezawa)

CHIKUSHINO, Fukuoka Prefecture--A long-standing onsen inn here is in hot water after being found to have violated a prefectural ordinance.

The Futsukaichi Onsen Daimaru Besso inn only changed the water in its large bath two days a year, when the inn was closed, according to Fukuoka prefectural officials and other sources.

The inn continued to let guests use the bath in such conditions, however. The water is supposed to be changed at least once a week.

The inn also regularly failed to put chlorine in the hot water and maintain the required concentration of the chemical in the bath.  

The prefectural health center has scrutinized the large bath’s hygienic conditions as it found last year that it contained up to 3,700 times the allowed maximum number of bacteria from the Legionella genus.

The inn’s management company declined to comment, telling the media that it will not make public details of its business.

The luxurious Daimaru Besso inn opened in 1865 and is known for where Emperor Hirohito (1901-1989), posthumously known as Emperor Showa, once stayed.

Natural hot spring water from its original source continuously runs to the Daimaru Besso’s large bath--a method to supply water to an onsen bath called “kakenagashi.”

The large bath also uses hot water that is circulated and filtrated.

A Fukuoka prefectural ordinance requires the entire amount of hot water in a public bath be changed at least once a week if it is filled with circulated and filtrated hot water and is used daily. 

The ordinance also requires the chlorine concentration of hot water in such a bath be 0.4 milligrams or more per 1 liter of hot water.

(This article was written by Yoshitaka Unezawa and Eiji Zakoda.)