Inside the aqueducts, there are numerous freshwater sponges that seem to do some additional filtration.
There use to be a lot of breweries in New York, mostly to do with the quality of the water. Much of that water infrastructure is at least a century old, and still going strong.
Rupert’s Brewery used to be up in the 80s on the East side. The mansion is still there and I like to imagine the dray horses barreling down that street to deliver beer to the saloons. In the amazing book by Harpo Marx called “Harpo Speaks” he recalls this vividly.