On Monday, the expo organisers announced that the popular daily fountain shows and a shallow pool area had been temporarily cancelled for deep cleaning due to bacterial contamination.
The aquatic show at the Water Plaza has been suspended since June 4, when Legionella bacteria of up to 20 times the legal limit were detected in the water, local media reported.
Another area, the Forest of Tranquility – a shallow 2.3 hectare (5.7 acre) reservoir in the centre of the venue where visitors can soak their feet – has also been closed for cleaning due to contamination.
“I’m disappointed because the only reservation I could get was for the water show,” a visitor told media channel News On Japan on June 4.

Legionella bacteria, found in aquatic environments, can cause respiratory problems if the contaminated aerosolised droplets are inhaled. Possible complications range from a mild flu-like Pontiac fever to the deadly pneumonia-type illness called Legionnaires’ disease.