The bulk of the water in New York Harbor is oily, dirty, and germy. Men on the mud suckers, the big harbor dredges, like to say that you could bottle it and sell it for poison. The bottom of the harbor is dirtier than the water. In most places, it is covered with a blanket of sludge that is composed of silt, sewage, industrial wastes, and clotted oil. The sludge is thickest in the slips along the Hudson, in the flats on the Jersey side of the Upper Bay, and in backwaters such as Newtown Creek, Wallabout Bay, and the Gowanus Canal. In such areas, where it isn’t exposed to the full sweep of the tides, it accumulates rapidly. In Wallabout Bay, a nook in the East River that is part of the Brooklyn Navy Yard, it accumulates at the rate of a foot and a half a year. The sludge rots in warm weather and from it gas-filled bubbles as big as basketballs continually surge to the surface. Dredgemen call them “sludge bubbles.” Occasionally, a bubble upsurges so furiously that it brings a mass of sludge along with it. In midsummer, here and there in the harbor, the rising and breaking of sludge bubbles makes the water seethe and spit. People sometimes stand on the coal and lumber quays that line the Gowanus Canal and stare at the black, bubbly water.
Joseph Mitchell
The Bottom of the Harbor, 1951