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Felipe Dana, Associated Press
In this Oct. 23, 2013 photo, a man works on the reforestation of mangrove forests along Guanabara Bay in Rio de Janeiro, Brazil. Rio’s Olympic committee has pledged in writing that the pollution problems will be fixed, and many had hoped the Olympics would force authorities to tackle decades of neglect and poor planning that have blighted waterways. Rio de Janeiro will host the 2016 Olympic Games.

RIO DE JANEIRO — Olympic sports federations say they will be monitoring efforts to clean up the polluted waters around Rio de Janeiro to prevent health risks to athletes at the 2016 Games.

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An Associated Press report this week showed nearly 70 percent of Rio's sewage is untreated and dumped into iconic beach areas like Copacabana and Ipanema and picturesque Guanabara Bay. Those waters will host several of Rio's events at the Olympics and Paralympics.

Rio organizers have been pressed by the International Olympic Committee to speed the pace of venue construction. Cleaning the water could add to delays in preparing for the games, which will cost about $15 billion in public and private money.