Most of NYC’s 150 year old sewage system is combined with stormwater runoff, according to
Swim Coalition

When it rains (as little as one tenth of an inch per hour), New York City’s combined sewer system’s capacity is overwhelmed and the mix of polluted stormwater from our streets and untreated, raw sewage from our toilets, sinks, and showers is discharged directly into our waterways making them unsafe to touch

The pictured stencils was made to educate viewers about their sewer systems and reduce the amount of street litter ending up in local waterways. Made by Riverkeeper, Gowanus Canal Conservancy, Newtown Creek Alliance, SWIM Coalition, and New York City Soil and Water Conservation District and funded by the New York State Pollution Prevention Institute.

the Gowanus Canal Conservancy has kicked off the stenciling project with two projects, one with community volunteers, and one in partnership with the Brooklyn Urban Garden School (BUGS). Students at BUGS spent the year researching issues facing the Gowanus Canal and working with their advisory group to design and execute a project to combat their issue of choice. Students worked with Gowanus Canal Conservancy to design a stencil and paint the drains near their school, completing 16 stencils and speaking to passersby and business owners along the way.

Riverkeeper offers a storm drain stencil manual and other tips to prevent plastic waste on their website.