People and pets told to keep out of river at Ham amid anger over Thames Water’s plans to pump treated sewage Swimmers are being warned not to enter the water at the first official bathing site on the River Thames, in south-west London, because of toxic blue-green algae in the water. The blue-green algal blooms are rare in moving water but are likely to be caused by the extreme heat, low river flow, and nutrient pollution from sewage waste. Thames Water’s Hogsmill sewage treatment plant, in Kingston upon Thames, is situated three miles upstream of the Ham bathing site. Continue reading...