05/31/24 @mberigan. An interesting question, Matt.
We live at the top of a high rise in the Historic Center of Manaus, and we can see a modern treatment plant from our windows. It's on the point where the Educandos River, which collects several igarapés (creeks) from the southeastern part of the city, meets the Rio Negro, a few miles from where the Negro meets the Solimões to form the Amazon Proper. The state is clearly very proud of this plant: it seems to be modern and well-maintained, and has painted on the wall, "A Work of the State of Amazonas. The Largest Sewage Treatment Plant in the North of the Country".
Still, I've always wondered about it. For one thing, "the largest treatment plant in the North of the country" only seems to cover the area of about one city block; maybe it's super-efficient. For another, the placement seems strange to me. The bairro of Educandos is densely populated but not very large, and surrounded on three sides by water, so I wonder where the plant draws from, and how. Maybe those igarapés that flow into the Educandos.
Manaus, like all of Amazonia, is crisscrossed by igarapés. In 1960, the city had about 343,000 residents, and my in-laws say that people were able to swim in a lot of those igarapés, particularly the ones more than 2 or 3 km from Centro. Since then, the city has grown enormously to the north, northeast, and northwest (Centro and Educandos are now the very tip of Zona Sul), and is home to over 2.1 million people, the seventh largest city in the country and the largest by far in the North. Nobody swims in those igarapés anymore, and sewage is the main reason. Someday I really should research how many other treatment plants we have besides the showpiece between the rivers. If that's the only one, it's woefully inadequate.
The main swimming beach of the city is in Ponta Negra, on the Negro well northwest of Centro, and alleged to be clean most of the time. However, Ponta Negra has become an affluent neighborhood of "Shoppings" and high rises, And where do all the effluents from those buildings go? Who knows?
One Christmas Eve (no kidding!) in the early years of the 21st Century, the Prefeitura passed a law requiring every multifamily building to have a pre-treatment plant for sewage and requiring older buildings to retrofit. The law never got any publicity, and clearly was enacted "for the English to see". Periodically, though, it resurfaces briefly. It did at Christmastime last year, and sent a thrill of horror through our condominium, which was built in the late 1960s, and has nowhere to retrofit any kind of pre-treatment plant. Then it disappeared again, so once more, who knows?
