Susan Barry, left, and Jo Robb, members of the open water swimming group Henley Mermaids, exit the river Thames after a swim, in Henley-on-Thames, England, Friday, June 14, 2024. Britain has become notorious as a place where a casual swim could lead to an extended visit to the toilet, if not the hospital. A torrent of news on dirty water has spilled into next month's election to determine which party controls government for the next four or five years. (AP Photo/Alberto Pezzali)
Endurance swimmer Joan Fennelly, member of the open water swimming group Henley Mermaids, shows a map of the river Thames on her smartphone, in Henley-on-Thames, England, Friday, June 14, 2024. Fennelly is undaunted by frigid water and long distances, swimming year-round in the wild. But she takes extra precautions in her own backyard. The River Thames is one of Britain's many waterways contaminated with sewage and agricultural pollution. (AP Photo/Alberto Pezzali)
Endurance swimmers Joan Fennelly and Jo Robb, members of the open water swimming group Henley Mermaids, enter the river Thames, in Henley-on-Thames, England, Friday, June 14, 2024. Fennelly is undaunted by frigid water and long distances, swimming year-round in the wild. But she takes extra precautions in her own backyard. The River Thames is one of Britain's many waterways contaminated with sewage and agricultural pollution. (AP Photo/Alberto Pezzali)
A general view of the river Thames, in Henley-on-Thames, England, Friday, June 14, 2024. Britain has become notorious as a place where a casual swim could lead to an extended visit to the toilet, if not the hospital. A torrent of news on dirty water has spilled into next month's election to determine which party controls government for the next four or five years. (AP Photo/Alberto Pezzali)
Susan Barry, member of the open water swimming group Henley Mermaids, swims in the river Thames, in Henley-on-Thames, England, Friday, June 14, 2024. Britain has become notorious as a place where a casual swim could lead to an extended visit to the toilet, if not the hospital. A torrent of news on dirty water has spilled into next month's election to determine which party controls government for the next four or five years. (AP Photo/Alberto Pezzali)
Endurance swimmer Joan Fennelly, member of the open water swimming group Henley Mermaids, shows a map of the river Thames on her smartphone, in Henley-on-Thames, England, Friday, June 14, 2024. Fennelly and other members of the Henley Mermaids, a group of wild swimmers, now consult the Thames Water phone app that shows sewage releases. They also do the sniff test before jumping in. (AP Photo/Alberto Pezzali)
Endurance swimmers Joan Fennelly and Jo Robb, members of the open water swimming group Henley Mermaids, prepare to enter the river Thames, in Henley-on-Thames, England, Friday, June 14, 2024. Fennelly is undaunted by frigid water and long distances, swimming year-round in the wild. But she takes extra precautions in her own backyard. The River Thames is one of Britain's many waterways contaminated with sewage and agricultural pollution. (AP Photo/Alberto Pezzali)
Endurance Swimmers Joan Fennelly, right, and Jo Robb, members of the open water swimming group Henley Mermaids, speak during an interview with The Associated Press, in Henley-on-Thames, England, Friday, June 14, 2024. Fennelly and Robb are undaunted by frigid water and long distances, swimming year-round in the wild. But they takes extra precautions in their own backyard. The River Thames is one of Britain's many waterways contaminated with sewage and agricultural pollution. (AP Photo/Alberto Pezzali)
Endurance swimmer Joan Fennelly, member of the open water swimming group Henley Mermaids, displays her swimming cap, in Henley-on-Thames, England, Friday, June 14, 2024. Fennelly is undaunted by frigid water and long distances, swimming year-round in the wild. But she takes extra precautions in her own backyard. The River Thames is one of Britain's many waterways contaminated with sewage and agricultural pollution. (AP Photo/Alberto Pezzali)
Jo Robb, member of the open water swimming group Henley Mermaids, prepares for a swim in the river, in Henley-on-Thames, England, Friday, June 14, 2024. Britain has become notorious as a place where a casual swim could lead to an extended visit to the toilet, if not the hospital. A torrent of news on dirty water has spilled into next month's election to determine which party controls government for the next four or five years. (AP Photo/Alberto Pezzali)
A group of people swim in the river Thames in Henley-on-Thames, England, Friday, June 14, 2024. Britain has become notorious as a place where a casual swim could lead to an extended visit to the toilet, if not the hospital. A torrent of news on dirty water has spilled into next month's election to determine which party controls government for the next four or five years. (AP Photo/Alberto Pezzali)
A view of a sign, in Henley-on-Thames, England, Friday, June 14, 2024. Britain has become notorious as a place where a casual swim could lead to an extended visit to the toilet, if not the hospital. A torrent of news on dirty water has spilled into next month's election to determine which party controls government for the next four or five years. (AP Photo/Alberto Pezzali)