PDBG & dry-weather captures

Back in 1981/1982, through Internacional de Engenharia (IESA), I coordinated a work called Projeto Rio and, immediately afterward, a “Guanabara Bay Depollution Program - PDBG”.

It was the first PDBG, when little or nothing was yet said about it.

The idea of the subject excited some people and led to a meeting in the BNH building (Banco Nacional da Habitação, today incorporated into CEF), on the corner of Av. R. Paraguai with Av. R. Chile, in downtown Rio. Sérgio Franklin Quintella (then president of IESA), Mário Andreazza (then minister of the interior and virtual candidate for president of the republic), José Reinaldo Tavares (then director general of DNOS), I and two or three others whom I do not remember took part.

There I heard that word for the first time: “depollution”, which came up in the middle of the conversation and was pronounced by Quintella. I found it not very technical, improper, I preferred “sanitation of the bay”. It sounded to me like “unmoveable”, but in ten minutes everyone was already using it, so I conclude that I am the one who does not understand these things of fashionable terminology.

But the main theme was to produce a PDBG based on what we knew about the subject.

Financed (paid for) by DNOS (National Department of Sanitation Works, today extinct but to which Brazil owes a great deal), “Projeto Rio” went from Ponta do Caju to the Sarapuí River, dealing with the “sanitation” of the western margin of GB, with 15 to 20 favelas, generically called “da Maré”.

In that work, we created the idea of making “dry-weather captures” to accelerate the recovery of GB. We made a very ingenious and quite developed conceptual project, which we applied to the basic design of small captures and others quite large, such as for the Mangue canal, for the Cunha canal, for the Irajá Canal and for the Pavuna River canal.

In this “Projeto Rio” I had the honor and luck of coordinating people such as Fernando Botafogo Gonçalves, Amarílio Pereira de Souza, Karl Kuster, and of having an extraordinary participative, proactive and liberal inspector, my professor Eduardo Pacheco Jordão, through FUNDREM. Jordão was against dry-weather captures because he thought there would never again be investment in sewers and that we would be trying to cover the sun with a sieve. But he did not prevent or hinder our creativity and enthusiasm. On the contrary, he supported and helped, even while disagreeing. He must have thought: “patience”, this will not last long.... Nowadays I have been told he is an enthusiast. In the end, we always all agreed that, in the end, one must converge toward the absolute separate system (sanitary sewage totally separated from rainwater), because our rains are tropical and frequent.

But returning to the subject that makes me record these reminiscences:

We put together many “cost curves” and convinced ourselves and many others that, with an investment on the order of 15% of the total necessary to implement a conventional sewage system, it would be possible to solve 75% of the GB pollution problem and that, if we implemented a dredging system with some 10 barges per day unloading 20 km off the coast, 300 days per year, it would even be possible to “rejuvenate” GB over a 30-year horizon.

There was an extra attraction: the designed dry-weather captures would retain 95% of the garbage brought in by rainwater and were 100% usable even for the conventional systems that would be built from them, that is, zero waste, and a great anticipation of results. For those who do not know, the first major problem of GB is the garbage and sediments that reach it.

It so happens that, once this PDBG 1 was concluded, the idea was very well accepted and understood by Andreazza and became associated with his image, and vice versa. In the struggle to become a presidential candidate, Andreazza was defamed and heavily accused of corruption. Having lost the race to be ARENA’s candidate to Paulo Maluf, who in turn lost the indirect elections to Tancredo, of MDB, the subject died.

They were apparently unfair accusations because, having been minister (Transport and Interior), powerful and for many years, he died poor and his children live without possessions, in the middle class.

When the subject was resurrected, it was in the RJ government, around 1990, between the end of Moreira Franco’s government and the beginning of Brizola’s second term, with Japanese financing (JICA) and from the IDB, suppliers, etc., but PDBG 2, let us say, was another program, it began with the construction of the WWTPs, spent more than ten times (in stable currency) what was foreseen in PDBG 1 and did not depollute 1% of GB. It was merely a “Spending Program in GB”.

Now, with the advent of the terminology “diffuse pollution”, dry-weather captures are gaining new momentum. May the main ones be done: Mangue, Cunha, Irajá. In Pavuna, for better or worse, an improvisation was made in order to be able to inaugurate the WWTP where the sewage did not arrive. But it can and should be improved. The projects exist and are very good.

Who knows, one day we may make a presentation about PDBG 1, although the copy volume I kept disappeared many years ago. But I still have Projeto Rio with the best “Dry-Weather Captures” I have ever seen conceived.

As a sailor, father and grandfather of sailors, GB is our home. A pity.

Memoirs of Eng. Miguel Fernández y Fernández

Miguel Fernández y Fernández, engineer, chronicler and columnist, member of the National Academy of Engineering and of the Institute of Engineering # written in Oct 2020 Rd, 5,086 characters.