Start of Olympic mixed relay triathlon includes swimming in the Seine River amidst worries over water quality

The mixed relay event for Olympic triathletes started on Monday morning with participants diving into the Seine River despite concerns over water quality. Swimming in the river had been prohibited since 1923 due to pollution, but recent improvements in water quality allowed for the event to proceed.

Representatives from World Triathlon, the International Olympic Committee, Paris Games organizers, and local authorities reviewed water tests the night before the event. The tests showed that the water quality at the triathlon site had improved and met the required standards for the competition.

Prior to the event, the Belgian Olympic committee decided to withdraw its team from the mixed relay triathlon after one of its athletes who swam in the Seine fell ill. It was uncertain if her illness was linked to the swim in the river.

Paris invested 1.4 billion euros in cleaning up the Seine by enhancing infrastructure, such as creating a basin to collect rainwater and upgrading sewer systems and wastewater treatment plants. Despite heavy rains during the Games leading to increased levels of fecal bacteria in the river, organizers remained confident that warm temperatures and sunlight would help reduce germs before each event.

Daily water quality tests were conducted to monitor levels of fecal bacteria, including E. coli, in the river. World Triathlon’s guidelines allow competitions to proceed as long as E. coli levels are below 1,000 colony-forming units per 100 milliliters.

The triathlon mixed relay consists of four-person teams, each member swimming 300 meters, cycling 6.8 kilometers, and running 2 kilometers. Athletes had previously swum in the river for individual triathlons, with some delays due to water quality issues.