Unlike combined sewers, “separate sewers” drain our roofs, curbs and streets directly to our local waterways without treatment. During precipitation, stormwater sweeps up pollutants like trash, oil, pet waste and sediment and carries them straight to our separate sewers and then our waters. Roughly 40 percent of New York City’s landmass is underlain by these drainage systems. Following rain events, these pollutants can make waters unsafe for recreation.
