[VIDEO] Why NYC Built Skyscraper-Sized Sewer Tanks

Beneath New York City, a colossal 7,500-mile subterranean network processes billions of gallons of waste daily, a system that has evolved over two centuries from a patchwork of forgotten infrastructure to modern marvels. Initially, in the early 19th century, New York struggled with sanitation, leading to cholera outbreaks due to a lack of a proper sewer system and contaminated drinking water from shallow wells. While the Croton Aqueduct in 1842 addressed the fresh water crisis, it inadvertently exacerbated the sewage problem as more water closets were installed, channeling waste into street gutters and the harbor. By the turn of the 20th century, the harbor was a biologically dead cesspool, prompting the formation of the Metropolitan Sewerage Commission and, eventually, a unified city charter in 1929. The subsequent construction of advanced wastewater treatment plants, such as the Wards Island Wastewater Treatment Plant in 1937 and the North River Wastewater Treatment Plant (now underneath Riverbank State Park) in 1986, marked a significant shift towards treating wastewater. Today, the system, including the iconic digester eggs of the Newtown Creek Wastewater Treatment Plant, captures and processes nearly all dry-weather wastewater, with the resulting biosolids being transported across states for agricultural use. The city continues to map its antiquated underground labyrinth using digital innovations, ensuring the complex system operates efficiently and sustainably.