“Unbearable”: Residents demand action against bad odors in Billings

Residents of the southern area of São Paulo have signed a petition demanding action from the authorities to resolve the problem of bad odors at the Billings Dam. The group reports that the “sewage odor” has impacted the health and quality of life of those who live and work near Billings.

“Last night I couldn’t sleep because of the bad smell,” said Mayara Torres, 30. A resident of the Pedreira neighborhood, the lawyer is the founder of the Direito Nosso project, an organization that works to defend the rights of peripheral populations, and is one of the leaders of the petition.

More than 3,600 people from neighborhoods like Pedreira, Interlagos and IV Centenário have already registered their names on the document since December 6. Residents are demanding that São Paulo City Hall and the state government develop an urgent plan to end bad odors and demand more inspections, cleaning and wastewater treatment in the dam area.

Nausea, nausea and dizziness

In comments on the signature collection platform, people say they feel bad because of the smell.

“We live with closed windows and doors in this heat and, despite this, we can’t wait to eat,” commented Sandra Ferreira. “I spend the day feeling sick, I can’t eat and I can’t even have visitors. This situation needs to be resolved,” said another user, who identified herself as Camila.

Yasmim Souza, 25, a logistics assistant, has lived near the Interlagos circuit for six years and says the situation has never been as bad as it is now. “I’ve never seen this smell like it is. It always gets worse at the end of the year, but now it’s much worse,” he told Metropolises.

She says she hasn’t been able to eat at home because of the problem. “We don’t even have the appetite to eat,” he says, noting that even the family dogs eat less at the end of the year.

The young woman also reports having suffered attacks of dizziness during each prolonged stay at home.

Teacher Iula Marques, 42, said the situation has affected students and staff at the school where she works, at Parque Residencial Cocaia, in Grajaú.

“It became unbearable. At first, we thought it was a problem at the school, but when we started researching, we saw that it was coming from the dam, it was everywhere in the region. It’s a smell that we can’t stand, it’s very strong,” he says.

Iula says the stench gets worse on sunny days and when it rains after many dry days. On these occasions, she reports feeling sick, dizzy and nauseous.

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Billings Dam on Avenida Mar Paulista

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Billings Dam on Avenida Mar Paulista

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Billings Dam in the Cantinho do Céu region, in Grajaú, south of São Paulo

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Billings Dam in the Cantinho do Céu region, in Grajaú, south of São Paulo

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Billings Dam in the Cantinho do Céu region, in Grajaú, south of São Paulo

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Billings Dam in the Cantinho do Céu region, in Grajaú, south of São Paulo

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Aquatic, at the Billings Reservoir, in the Cantinho do Céu region, in Grajaú, in the southern zone of São Paulo

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Where does the smell come from?

Coordinator of the Environmental Analysis Laboratory of the Water Pollution Index Project (IPH) of the Municipal University of São Caetano do Sul (USCS), biologist Marta Marcondes affirms that the strong odor is the result of the action of microorganisms amid the pollution of the dam.

“These micro-organisms are what we call cyanobacteria. When we start to smell this odor, it means that there is an exacerbated increase in these micro-organisms,” explains the researcher who has been studying the quality of the water from the dam for years.

Until 2024, the manager of the dam was the Empresa Metropolitana de Águas e Energia (Emae), which was bought by Sabesp the same year. The Environmental Corporation of the State of São Paulo (Cetesb) is the environmental agency of São Paulo responsible for developing control, authorization, inspection and monitoring actions for potentially polluting activities.

Wastewater and eutrophication

Marta says untreated sewage dumped in Billings, along with the overturning of the Pinheiros River, which carries water from the river to the dam on rainy days, helped accelerate a phenomenon known as eutrophication.
“Eutrophication is when you throw a lot of organic matter into a body of water and that body of water reacts. It’s the microorganisms that break down that organic matter, that use the oxygen to break it down. When I add a lot of organic matter, the microorganisms use up all the oxygen that’s there.”
The phenomenon makes the water cloudy and also leads to the death of fish. According to the biologist, as oxygen decreases, microorganisms enter the scene and, to carry out decomposition, release compounds responsible for the bad odor, such as methane, sulfide and sulfate.
The researcher says it is necessary to invest in cleaning and oxygenating water to improve the situation.

MPSP triggered

Mayara says the odors have also impacted businesses and services in the area. The lawyer claims that employees of a gym in Estrada do Alvarenga use sprays to try to alleviate the smell of the dam among their clients. There are also reports of restaurants experiencing sales due to this issue.

Through the Direito Nosso Project, she contacted the São Paulo Public Prosecutor’s Office and requested the opening of an investigation and public civil action to investigate responsibility for the environmental and health damage resulting from the bad smell.

The group also sent a letter to the Secretariat of Environment, Infrastructure and Logistics requesting a meeting with Sabesp, Cetesb and Emae to discuss a solution to the matter.

“People just want to live well, to rest after a day of work. It’s very frustrating to see that you have to make an effort to achieve the minimum,” says Mayara.

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Garbage on the banks of Billings Dam

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Billings Dam seen from the Jardim Apurá neighborhood

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Illegal housing development on the banks of the Billings Dam

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Billings Dam

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Other side

The city of São Paulo says it periodically cleans about 10 streams that flow into the Billings Reservoir, eliminating about 37 tons of waste per month. In addition, it promotes the collection of common, recyclable and sanitary waste throughout the territory.

According to the municipal administration, under the current administration, the Mananciais program has already transformed the lives of more than 40,000 families living around the Billings and Guarapiranga dams with the delivery of 1,689 new housing units between 2021 and 2004, in addition to parks, recreational areas and urbanization projects, for a total of more than 3.77 billion reais in investments.

“There are, to date, no consolidated records that confirm a direct relationship between complaints of nausea, dizziness or headaches and the odor coming from the Billings Dam. Teams from the Municipal Health Department (SMS) are still responsible for evaluating all patients. As a preventive measure, the population should keep environments ventilated, avoid prolonged exposure to the odor as much as possible and consult the referral health unit in case of persistent symptoms or worsening of the clinical condition”, completes the note from the town hall.

When contacted, Sabesp, Emae and Cetesb did not respond to this information. The space remains open for demonstrations.