Smelly Rio de Janeiro water supply has residents on edge

David Biller & Diane Jeantet

RIO DE JANEIRO (AP) – There’s a creeping sense of alarm in Rio de Janeiro after more than a week of foul tasting and smelling tap water in dozens of neighbourhoods. Rumours are flying, and residents are hoarding bottled water.

People in the metropolitan area have taken to social media to show glasses of water that appears reddish or brownish. Several supermarkets visited by the Associated Press yesterday had run out of bottled water.

There have been rumours – denied by officials – that the state water utility, Cedae, would cut off supply of water to millions of residents, or that tests have determined the water unfit for consumption.

Mariana Bretas, 29, received a viral text message saying people must plug their ears with cotton when showering.

“I don’t know if it’s true, but we’re getting scared,” Bretas said after buying five litres of water.

Workers toss down bottled water to be distributed in supermarkets in Rio de Janeiro, Brazil. PHOTOS: AP
A woman buys bottled water at a supermarket in the Copacabana neighbourhood of Rio de Janeiro

Cedae has said the peculiar water is due to geosmin, an organic compound that is innocuous, and that the water meets Health Ministry requirements. Even so, it said it will begin using powdered activated carbon at the start of treatment to curb geosmin.

At a press conference yesterday, Cedae officials reiterated that geosmin was the cause of the smell and taste, and insisted there was “nothing alarming” about its levels in the city’s water reserves.

The number of cases of diarrhoea, gastroenteritis and vomiting in two health clinics of Rio’s west zone doubled between December 20 and January 5 over the same period last year, but it’s too early to associate higher incidence of symptoms with contaminated water, particularly after holiday season parties, the state health secretariat said in an emailed statement.

Rio Gov Wilson Witzel’s patience has worn thin. On Tuesday night he called for analysis of the water’s quality as well as of the utility’s management.

“The disorder the population has been suffering due to the problem with water provided by Cedae is inadmissible,” Witzel said on Twitter.

“The company must accelerate its ultimate solution to improve water quality and sewage treatment in cities near the springs. The consumer cannot be harmed.”

Maurício Oliveira da Silva, a 51-year-old resident of Complexo de Alemao, a group of slums in Rio’s north zone, said coloured water had been coming out of the tap for several days until it improved yesterday. Still, he accused the government of lack of interest in some of the state’s areas.

“We feel abandoned,” da Silva said, adding that poorer folks like himself couldn’t afford to buy gallons of bottled water. “We feel powerless.”

As for the water’s colour, Cedae officials yesterday attributed it to the piping systems of individual homes, something for which the company can’t be held responsible.

“In my house, I always drink Cedae’s water,” the company’s president Helio Cabral assured journalists.

Geosmin is produced by different bacteria, including cyanobacteria, commonly known as blue-green algae. Its sharp, earthy flavour and pungent smell are more noticeable to some people than others. But the compound is not hazardous, said Celeste Journey, a water quality specialist with the United States Geological Survey in Columbia, South Carolina.

“If it’s just a geosmin problem it’s not a human health issue at all,” Journey said. “It’s usually just an aesthetic issue. It doesn’t taste very good.”

However, cyanobacteria also can produce toxins such as microcystin, which forced a shutdown of the drinking water system in Toledo, Ohio, in 2014, after blue-green algae formed on nearby Lake Erie. A study by the United States (US) agency concluded that utilities detecting geosmin in their water should test for the presence of toxins formed by cyanobacteria, which have no taste or smell, Journey said.

Those toxins can cause gastrointestinal symptoms such as vomiting, she said.

The level of cyanobacteria in Cedae’s most recent testing is below that at which protocol requires additional testing for potentially harmful toxins, but anyway the company has begun carrying out such analysis daily, according to the company’s press department.

Waterways contaminated with cyanobacteria often are green or reddish, but such discoloration typically fades as water is treated for drinking, Journey said.

Utilities in the southeastern US, where geosmin is a recurring problem, often use powdered activated carbon filtration systems, she said. Like a sponge, carbon absorbs the geosmin and removes it from the water.

Cedae’s Cabral denied media reports that the head of the water treatment station that provides water to Rio’s Baixada Fluminense area had been dismissed, but rather said he’d merely changed departments under a previously scheduled move.

The facility is one of the largest in the world and receives water from the Paraiba do Sul River, but also several sewage-contaminated streams, which Cedae does an insufficient job of treating, said Joao Paulo Machado Torres, a professor of environmental biophysics at Rio’s federal university who has previously studied the city water system.