The document discusses New York City's water system, including where the city's water comes from in watersheds located in the Catskill Mountains, how it is tested and transported through pipes to city residents, and where wastewater goes after being drained, including potential overflow issues if the sewer system becomes overwhelmed and releases untreated water directly into local harbors. The document encourages readers to conserve water, be mindful of pollutants entering the water system, and to educate themselves and others about these water issues.