How NYC is Keeping Our Waterways Trash Free - DEP

Environmental Protection


Trash in Waterways

How NYC is Keeping Our Waterways Trash Free


When it rains, trash and debris on the street can end up in the city’s catch basins. From there the trash and debris can make its way into the Sewer System, and sometimes all the way to our waterways. New York City implements a variety of programs to intercept trash and debris before it becomes waterborne.

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Street Sweeping

The New York City Department of Sanitation (DSNY) sweeps more than 6,000 miles of roadway each day. Removing trash and debris from city streets reduces the amount that reaches waterways.

Street cleaning regulation signs indicate a block’s alternate side parking rules and the schedule lets Sanitation teams clean the city’s streets with mechanical brooms, also known as street sweepers. The street cleaning regulations apply in metered parking areas, too. Cars must be moved to allow for street cleaning or drivers will be issued a ticket. Remember, it’s never legal to double-park your vehicle, even during alternate aside parking hours.

The city suspends alternate side parking for certain holidays, severe weather or emergencies:

Learn more about Alternate Side Parking.

Report Missing or Faded Street Cleaning Signs.

Catch Basin Inspection Program

Catch basins serve to collect rainwater and direct it to the sewer system. Their design also helps prevent trash and debris from entering the sewer system in three ways. First, grates keep large items out of the basins. Second, sumps allow heavier items to settle to the bottom and stay out of the sewer system. Finally, hoods shield the basin’s pipe outlet and help prevent floatable items from entering the sewer system.

DEP inspects catch basins regularly and in response to complaints. Clogged catch basins are cleaned and necessary repairs are made.

Remember, it is illegal dump anything into a catch basin or sewer. This includes, but is not limited to:

Sewage, wastewater, or pool water

Food grease or cooking oil

Automotive oil

Concrete, cement, sand, or other construction material

Gasoline, chemicals, or natural gas

You can report a Problem with a Catch Basin or Dumping in a Catch Basin or Sewer to 311.

Wastewater Treatment Plants

In parts of the city serviced by a combined sewer system, stormwater runoff is combined with sanitary sewage from homes and directed to one of 14 wastewater treatment plants. At the wastewater treatment plant, screens remove large pieces of trash and debris including rags, sticks, newspaper, s cans, bottles, plastic cups and other similar items. The trash and debris removed from the screens is transported to landfills.

Once past the screens, the wastewater enters sedimentation tanks. Here the flow of water is slowed, allowing heavier solids to settle to the bottom and floatable materials to rise to the top. The settled solids are further treated, with sand, grit and gravel being sent to landfills. The floatable material, such as grease and small plastics, is skimmed from the surface of tanks and properly disposed. Learn more about New York City’s Wastewater Treatment System.

Combined Sewer Overflow Reduction

Sometimes, during heavy rain and snow, combined sewers receive higher flow than the wastewater treatment plants can handle. When this occurs, a mix of excess stormwater and untreated wastewater can discharge directly into the City’s waterways in what is known as a combined sewer overflow (CSO). During a CSO, both the trash and debris from both streets and homes can end up in local waterways.

DEP is working to reduce CSOs. Improvements to gray infrastructure, such as upgrades to wastewater treatment facilities and the construction of CSO retention facilities and tanks, help DEP handle higher flows of combined wastewater. Construction of green infrastructure, like rain gardens, helps reduce the flow of stormwater runoff entering the city’s combined sewer systems. Together, these efforts reduce trash and debris reaching waterways through CSOs. Learn more about Combined Sewer Overflows.

End-of-Pipe Controls

Floating booms and nets are used at certain outfalls to help contain floatable trash and debris after it has been discharged to a waterway. Following heavy rain events, small vessels conduct inspections of booms and nets. If necessary, skimmer vessels are dispatched to retrieve collected floatables from the booms and nets. During dry weather, booms and nets are inspected at least once per week.

Education and Outreach

DEP’s Office of Education provides Pre-K–12 students, college students, and educators with a wide range of free programs and resources about New York City’s water supply, wastewater treatment systems, stormwater management, sound and noise quality, and other environmental topics. Water quality and stewardship opportunities are important themes in these education programs and resources. Learn more about our Educational Programs.

DEP also provides resources for business owners about the most common environmental compliance issues, including noise requirements, grease and fat disposal, and backflow prevention. Learn more about Backflow Prevention Devices.

Similarly, other city agencies also conduct education and outreach programs that help reduce trash and debris:

Learn about Collection and Cleaning from the Department of Sanitation.

Learn about the Zero Waste Initiative.

On-Going Monitoring

Visit Harbor Water Quality for more infomration about our harbor monitoring program.

Download the 2018 Floatables Monitoring Progress Report

To view Floatables Monitoring Progress Reports from previous years, visit our Publications Database and search for “Floatables Monitoring Progress Report.”