Belgium withdraws from mixed relay triathlon after athlete who swam in Seine River falls ill

The Paris Games in Switzerland are altering their roster due to athletes from both countries falling ill after recent triathlon events. The cause of the illness is uncertain, but concerns have been raised about the water quality in the Sun River, where athletes were scheduled to swim. Organizers have faced criticism for this decision, especially after a spike in E. coli levels following recent rainfall, which led to the postponement of the first event in the river.

What efforts were made by organizers to address the water quality issues?

How did recent rainfall affect the water quality in the river?