"A major part of Rio’s winning Olympic bid was a plan to capture and treat 80 percent of the sewage that flows into Guanabara Bay, something organizers now admit will not happen — certainly not by August, if ever. For the past couple of years, sailors in training for the Olympics have reported putrid conditions and floating debris, their stories and shocking pictures drawing worldwide attention to the tainted water. Some have unsuccessfully called for the relocation or postponement of sailing and other open-water events, such as kayaking, triathlon and marathon swimming.
But Olympic athletes and international visitors will come and go. Remaining will be roughly nine million people who live in the watershed of Guanabara Bay. About half of them are not hooked up to sanitation systems."