Stormwater in New Haven


(c) Chris Banks / Wayworks


New Haven in recent years has significantly reduced its point source pollution—pollution coming from a single, identifiable source like a gas station or a household. But the Long Island Sound is still plagued by nonpoint source pollution like stormwater runoff and combined sewer overflows (CSOs). The majority of New Haven is covered with impervious surfaces like roads, buildings, and parking lots that generate a lot of stormwater runoff, especially during large rain events.

In combined sewer systems, like that of the West River watershed, stormwater doesn’t drain into a separate set of pipes, but mixes into the sewer system. This water is carried to the treatment plant and discharged into the Sound. During most storm events, especially when the rain is heavy, water overloads the system and a mixture of sewage and stormwater drains directly into the West River (and other urban waterways).

These challenges present a unique opportunity for researchers at Yale School of Forestry & Environmental Studies to test the effectiveness of green infrastructure in New Haven.