The green diving pool is supposed to be crystal clear, like the other pools. Someone apparently dumped hydrogen peroxide instead of chlorine into the diving pool, which reacted badly with the chlorine, and caused an algae bloom. It got darker and darker every day, and now it's just an oblique murkiness that smells like Olympic farts. They've tried filtering and changing the chemistry of the water, nothing has worked.
The solution is to drain the pool and fill it with clean water from the nearby water polo pool, which won't be used again in these games. It'll take, they say, 6 hours to drain and clean the pool, and then 4 hours to refill it with clean water. Supposed to be finished a few hours before the synchronized swimming events start. Oh, and they're just gonna drain the pool into the city's sewer system, so that it can dump into the bay where they are doing the rowing, canoeing, sailing, triathlon and open water swimming.
But the best line so far from these Olympics is from the green diving pool, spoken by Mario Andrada, chief spokesman and head of aquatics for Rio 2016, when he said, "Chemistry is not an exact science."
Then he later doubled down and said of the nearly 1 million gallons of water in the pool, "The rain didn't help. It diluted the chemicals we were using."