Having only touched Tokyo before heading to northern Japan, Typhoon Nepartak spared the organizers of the Olympic Games a few cold sweats. Sometimes heavy, the overnight showers caused the 15-minute postponement of the women’s triathlon, which started on Tuesday July 27 at 6:45 a.m. from the Odaiba nautical base, located on a polder in Tokyo Bay.
More agitated than for the men’s event, organized the day before, the water at nearly 30 degrees but still below the regulatory limit of 32 degrees, did not present any health problem either, a major concern for the triathlon but also as for the open water swimming events scheduled for the beginning of August.
Because the typhoon does not only represent a risk for the rowing events, initially scheduled for Tuesday and postponed to Wednesday for fear of “Uneven and potentially unmanageable racing conditions”, says the official statement. The rains it causes can saturate Tokyo’s dilapidated water treatment network, which is more than a century old and whose particularity is to manage both rainwater and wastewater at the same time before discharging it into the seven rivers and dozens of streams and underground canals that lead to the bay.
“In the event of heavy rains, the treatment capacities can be exceeded, so that the waste water, which includes the water from the toilets, is not treated except by a simple addition of chlorine, and flows into the watercourse “, explains Junji Hashimoto of the independent research center Aquashere. Tokyo Bay also receives wastewater – sometimes untreated – from the departments of Saitama, Chiba and Ibaraki, or nearly 30 million inhabitants.
In periods of strong heat, this can cause red tides, a proliferation of coliform bacteria or Escherichia coli (E. coli), even foul odors in the bay and therefore at the nautical base, ” a closed body of water where pollutants tend to stagnate ” says Hashimoto.
22 tonnes of sand dumped on the most polluted sludge
The problem is old since swimming and fishing activities have almost always been banned since the development, in 1996, of the artificial beach in Odaiba. This did not prevent the organizers of the Games from selecting it to make it the starting point for the triathlon and open water swimming events.
A long contested choice. In 2014, the newly elected mayor of the capital, Yoichi Masuzoe (2014-2016) worried about the pollution of the area and mentioned a move of the site to Yokohama, south of the capital. Strong reactions, among others from the district of Minato – on which Odaiba depends – had dissuaded him.
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