Widespread complaints over foul-smelling drinking water in Rio de Janeiro have triggered a run on supermarket bottled water, though the public utility denied any health risk Wednesday.
Rio governor Wilson Witzel set alarm bells ringing in a Twitter post on Tuesday, saying the situation -- fueled by social media rumors -- was "unacceptable" and calling for a "rigorous investigation."
Moving to calm growing fears, public water utility Cedae attributed the problems to the presence of geosmin, a harmless organic compound, insisting the resulting earthy-tasting tap water was safe to drink.
"The results of the analyses show the presence of geosmin, at a rate sufficient to change the taste. But there is no risk to health," Sergio Marques, the official in charge of water quality, told a press conference.
Cedae later said it had fired the head of the Guandu treatment plant, which supplies nearly 80 percent of Rio's drinking water.
It said the supply from Guandu would be treated with carbon in the coming days to get rid of the geosmin.
According to O Globo newspaper, nearly 70 districts of the capital have been affected.
It reported that more than 1,300 cases of gastroenteritis were recorded over the last 15 days in Santa Cruz in the west of Rio, where water quality complaints were rife.
Cedae's president Helio Cabral apologized "to the whole population for the problems in the water supply," which began earlier this month.
The problem has been exacerbated by false rumors circulating on social media that the water was toxic.
Despite assurances, many Rio citizens were taking no chances. In supermarkets, mineral water stocks have been selling out and long queues are formed as soon as they are replenished.
Geosmin is also responsible for the earthy taste in some vegetables.