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The information here presented are results of research and have scientific and dissemination purposes without commitment or responsability to guarantee the water quality of any of beaches studied.

Traduza Esta Página Para Português.

The bath anywhere is the bather's own risk

Access The Bathing Map


Here we provide data from our research on the health and quality of bathing in 60 beaches on the coast of Rio de Janeiro and Niteroi, based on samples collected and analyzed by the State Enviromental Institute (Instituto Estadual do Ambiente – INEA). Data were classified by the beach, and the latest report available can be easily located on the institute's website in the sector monitoring beaches of the state of Rio de Janeiro.

Still, an historical perspective (2014-2016) of each beach is displayed. We expect this site to be a useful alternative source of information for the locals, residents and tourists as it is based on quality information on sanitary conditions of the beaches of Rio de Janeiro.

About Us

The Hydrobiology Laboratory was created in 1995 from the Environmental Assessment Laboratory and the legacy of Professor Leticia M. Mayr. Our mission is to study the water quality in various environments such as the Bay of Guanabara, Ilha Grande Bay, Atlantic Ocean and rivers of Brazil.

Another important mission is to function as an analytical center or multi-user laboratory chemical and microbiological analysis of water. To know us a little better know our Team.

Wha is Bathing ?

What Is Balneability

Bathing is the quality of water intended for primary contact recreation, the ability that a place has to allow bathing and sports activities in its waters.

The evaluation of bathing patterns is generally based on the and fecal coliforms (FC) and Enterococcus (ENT) which, although not pathogenic, are found in large amounts in human faeces and are more resistant than the other microorganisms and they are easily detected.

They are therefore considered good indicators for pollution from domestic sewage, and many countries use them for this purpose.

How Bathing is Evaluated ?

According to the criteria established in Resolution 274/00 of the National Council of the Environment (CONAMA), the beaches are ranked according to the bathing in 2 categories: Proper and Improper and the first gathers three distinct categories: Excellent, Very Good and Fair.

This classification is made according to the amount of bacteria found in fecal samples.

We used data on the health quality collected and analyzed by the State Environmental Institute - INEA. Samples were collected weekly for up to 60 beaches of the coast of Rio de Janeiro, Niteroi and Guanabara Bay.

Samples were analyzed by standard methods and internationally accepted as to SM9221E2 Fecal coliforms and SM9230 for Enterococcus, both published by American Public Health Association - APHA (2012). The results of the reports (% of proper or improper) were extracted manually bulletins available in State Enviromental Institute website.

Data were organized by the beach, and the latest available report can be found/seen in the bathing section in the State Enviromental Institute website

What The Results Mean

A Beach considered "Properly" need to present a maximum of 1000 fecal coliforms in 80% of a set of samples from each of the previous five weeks, taken from the same location. The lower the number of coliforms, better classified it becomes (satisfactory, very good and excellent, which is not detailed in the State Enviromental Institute report).

A beach is considered "Inproperly" when in the assessed section is observed one of the following events:

  • Failure to meet the criteria for the waters themselves;
  • Value obtained in the last sampling exceeds 250 fecal coliforms or E. coli 200 or 25 enterococci per 100 milliliters;
  • High or abnormal incidence in the Region of communicable diseases by water route indicated by the health;
  • Presence of waste or sewage, solid or liquid, including sewage, oil, grease and other substances, which can pose risks to health or make unpleasant recreation;
  • Bloom of algae or other organisms, until it is proven that it offers no risk to human health;
  • Other factors that contraindicate temporarily or permanently the exercise of the primary contact recreation.


Hidrobiology Laboratory - Biology Institute - Federal University of Rio de Janeiro

Street Professor Rodolpho Rocco, CCS Building, Block A, office A1-71 - Rio de Janeiro - RJ

Tel: +55 21 3938 6303 | Email: