Why is the Hudson River so dirty

This is how New York gets its five billion liters of water every day

The city of New York uses about 5 billion liters every day. Where does it come from? Drawing the water from the Hudson or East River was never seriously considered. Both rivers are estuaries with considerable salinity due to the connection to the Atlantic. They were also too dirty in the early decades of the 20th century, when New York was growing explosively and you had to worry about where to get massive amounts of water. (Incidentally, the water quality of the rivers is better in 2018 than it was then, here article on NY Aktuell)

Suppliers of the water for New York are 3 large Systems Water Systems ’, as you can see them here (primarily a system of rivers that are connected to reservoirs). All three are far from New York - up to 200 km and are in areas that are relatively sparsely populated and mostly mountainous. 97% of the water comes from the Catskills and Delaware systems, about 3% from the Croton system.

Dozens of reservoirs are fed by the ‘Water Systems, which, by the way, are guarded by a police unit with 200 men. The two largest reservoirs, Pepacton and Asokan, have a capacity on the order of 500 billion liters. The water at the reservoirs is examined and the best water available that day is released and flows south through tunnels and aqueducts towards the city of New York. The two main aqueducts are the 150 long Catskills and the 135 km long Delaware Aqueduct. When the Catskill Aqueduct was completed in 1917, it was such a marvel of engineering that it has been compared to the Panama Canal, which was being built at the same time. The Delaware Aqueduct, which began operations in the mid-1940s, is so massive that submarines have been used for damage inspections.

The water from both aqueducts then flows into the huge Kensico Reservoir, about 25 km from the city limits. In Kensico, pile is added to the previously untreated water and it is disinfected, primarily with UV light, in perhaps the largest system of its kind in the world. UV light provides excellent protection against microorganisms such as Cryptosporidium and Giardia, which pose a threat to New York water.

From Kensico, the journey of the water goes a little closer to New York, to the Hillview Reservoir in Yonkers, which already borders the Bronx. Here you adjust the water supply so that in the morning and in the evening, when people go to work / come from work, and at other peaks in demand, appropriate amounts of water are available. From Hillside the water reaches distribution points in the city through 3 huge tunnels. Tunnel 1 was completed in 1917, tunnel 2 in 1936. Work on tunnel 3 has been going on since 1970. 28 years later, in 1998, operations began delivering water to the Bronx and northern Manhattan, and since 2003 Tunnel 3 has also been delivering to more southern parts of Manhattan. At some point in the coming decades, the work should be completed and Tunnel 3 will then deliver water to the whole city. Nobody knows exactly when, as the project is repeatedly slowed down or comes to a standstill because of the immense administrative and political costs. Once this is done, there will finally be an opportunity to carry out necessary inspections and repairs in Tunnels 1 and 2.

As with the aqueduct system in ancient Rome, the water from the springs, which are up to 200 km away, does not need any technical aids to reach the city - gravity is sufficient. Once in town, the water even makes it to the 6th floor of a building. Higher buildings need water tanks and pumps. (NY Current article on water tanks here)

New York is one of the cities with the best drinking water in the USA. After the water has reached New York, it is continuously tested at around 1,000 test centers throughout the city. The quality of the water is so high that the hundreds of thousands or millions of bottles of water that are sold in stores every day, scientifically speaking, offer no health advantage over normal tap water - some New Yorkers even say that the water is the secret behind the excellent Taste of New York Bagels and Pizza is.