Opinion, by Alfonso Stefanini

RIO DE JANEIRO, BRAZIL – The Jardim Botânico do Rio de Janeiro (Botanical Garden), located in the South Zone of the city, was founded in 1808 and is currently a UNESCO biosphere reserve and World Heritage site. But the Botanical Garden now has a steady flux of sewage and greywater seeping into its main river, Rio dos Macacos, and its water tributaries.

Alfonso Stefanini, environmental consultant in Rio de Janeiro.

The Rio dos Macacos River traverses the length of the park and at the end of its course, before it flows into to Rodrigo de Freitas Lagoon, the smell and waste is particularly noticeable.

The wastewater comes from three main sources: faulty public water infrastructure lines, local industrial centers, and residences. Independent of rain, sanitary and storm drain sewer effluents mix with clean water coming down from the mountains of the Floresta de Tijuca National Park.

Over the years, the Botanical Garden has been knee-deep in controversy over a historical housing issue related to the consented and illegal squatting in the Garden’s biological corridor that connects it to the Floresta de Tijuca National Park.

The corridor itself, an indispensable ingredient in maintaining the biodiversity and ecological services for the Botanical Garden, is at risk of being completely fragmented by irregular housing.

Citizens of Rio pay a tax that is meant to pay for the sanitary services in the city, and the tax amount is higher for residents living near the Botanical Garden as opposed to those living on the outer boundaries of the city.

One thing is for sure: no one in Rio de Janeiro really knows where water residue goes when the toilet is flushed. When it rains in Rio, the city is taken over by mayhem as most sewage drains overflow with contaminated water.

If the drains don’t overflow, it’s still likely that you’ll get a whiff of untreated water. The situation is far from the acceptable sanitary standards that the taxes are supposed to maintain.

The city suffers from a lack of adequate infrastructure that can effectively capture all the effluents that come from residences and businesses. In the state of Rio de Janeiro, over two billion liters of raw sewage end up in fresh water sources on a daily basis and only thirty percent of the urban population in the state has a sanitary infrastructure to properly handle its wastewater.

It is unfortunate that world’s the biggest contributor to freshwater pollution is untreated sewage, which can lead to public health issues and a lack of clean water. In such a situation, a river, such as Rio dos Macacos, becomes an environmental indicator of the general health of a city.

I believe the Botanical Garden should conduct a wastewater detection campaign using simple technologies such as biodegradable tracing dyes and acoustic leak electronics. These methods are safe and easy to use for determining the source of contaminants.

My suggestions to the Botanical Garden are the following:

Step 1
Perform a general wastewater detection check throughout the Garden, identifying the main sources of pollution contaminating its river and tributaries.

Step 2
Test all factories and commercial sites near the Botanical Garden to identify potential contamination leaks that could infiltrate the garden.

Step 3
Initiate an environmental campaign that encourages residents to test their water pipes in order to help locate possible contamination leaks.

Step 4
Incorporate a monitoring system that ensures that the river will stay clean and free of contaminants.

The clean up of the Rio dos Macacos River could serve as a potential catalyst and exemplary model for conducting other water cleaning projects throughout the city of Rio de Janeiro.


Alfonso Stefanini has an MA in International Environmental Policy from the Monterey Institute of International Studies in California and a BA from Hampshire College. Alfonso lives in Rio de Janeiro, and he can be reached at: Ecobrasilis@gmail.com.


  1. Sorry to say, but what part of this surprises you?

    We live in a city where the public showers at the beach aren’t fit for dogs, let alone humnans; and you can’t brush your teeth with tap water…

    I think that Brazil had a lot of gaul to host the Rio+20 conference. And certainly can’t opine on world issues.


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