First the Olympic diving pool in Rio turned green, and that was weird. Then, on Friday, Games officials closed it to decontaminate the water. That was even weirder. Then a German diver said that the whole building “smells like a giant fart.”
The problem began Tuesday during the synchronized diving events. By Wednesday, the murky green color had spread to the nearby water polo pool. Friday morning, the diving pool was closed. Rio Olympic organizer spokesman Mario Andrada says that the changing color was the result of increased alkaline levels, much like an aquarium can turn green when not monitored properly. “When we went to fix the green, there was a discussion about the best chemicals. We can’t use too much chemicals in the water because athletes are training in it,” Andrada told the Associated Press in Rio.
“We certainly could have done better in the beginning to prevent the water from turning green. Once it turned green, we again made another bit of a mistake.”
And then it rained. That may have made things worse. “Chemistry is not an exact science,” he said. “Some things, as you can see, went longer than expected.”
One quick fact check: “Chemistry is an exact science,” says Ernest Blatchley III, an environmental engineer at Purdue University who studies water chemistry in pools and drinking water systems. “If this problem is caused by algae, it’s not just a chemical problem, it’s also a biological problem.” In fact, an entire aquatic ecosystem may have sprouted up in the Olympic diving pool.
Chlorine would kill most of the algae, but not all of it. And it’d take physical filtration to pull out the dead algae. Oh, plus, the reaction between the algal cells and chlorine produces a group of chemicals called chloramines, which give indoor pools that “chlorine smell,” and trichloramines that irritate human tissues like skin and eyes.
Blatchley was careful to say that he has not seen the water samples from the pool and has no data from Rio. “But there are thousands of outdoor pools maintained in sunny climates where algal growth does not take place and is not a problem for the pool,” he says. It does take some expertise to do it without hurting swimmers. “I would not say it’s a trivial effort. You have to be disciplined and conscientious to maintain a pool in those circumstances.”
So what can the Rio folks do? Karen Robinson, who handles sales calls at Robell Industries, which distributes pool chemicals throughout the Northeast US, suggested feeling around the sides of the pool for algae. “That should help,” Robinson says.
But is that green color … normal? “We don’t hear of it that often,” she says.
The pool reopened for the women’s springboard competition on Friday afternoon. It appeared that the color improved slightly, to a cloudy aquamarine.