Skip to content

Frequently Asked Questions About the Gowanus Superfund Project

Here you’ll find answers to some of the most frequently asked questions about the Gowanus Canal Superfund Project. If your question is not answered below, please use the Contact Us page, email us at or call our hotline at (718) 569-5762.

The Gowanus Remediation Team, abbreviated in various materials as GRT, is the group of contractors and professionals completing the EPA mandated cleanup and environmental remediation of the Gowanus Canal.

The Gowanus Canal is a 100-foot wide, 1.8-mile-long canal in the New York City (NYC) borough of Brooklyn, Kings County, New York. The canal is bounded by several neighborhoods, Gowanus, Carroll Gardens, and Red Hook. Cobble Hill and Boerum Hill are north and Park Slope, east of the canal. The canal begins at Butler Street, between Bond Street and Nevins Street, and empties into New York Harbor

Formally known as the National Priorities List, The United States EPA’s Superfund program is responsible for cleaning up the nation’s contaminated land and waterways based on their ranking on the National Priorities List and responding to environmental emergencies, oil spills and natural disasters. To protect public health and the environment, the Superfund program focuses on making a visible and lasting difference in communities, ensuring that people can live and work in healthy, vibrant places.

The Gowanus Canal was built in the mid-1800s and was used as a major industrial transportation route. Many historical industries operated along the canal. In addition to the legacy industrial pollution, contamination flows into the canal from overflows from sewer systems that carry sanitary waste from homes and rainwater from storm drains. Numerous contaminants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls and heavy metals, are found at high levels in the sediment in the canal.

In April 2009, EPA proposed adding the Gowanus Canal to the National Priorities List (NPL). EPA performed field work to characterize the nature and extent of contamination in the canal; determine the human health and ecological risks from exposure to contamination in the canal; identify the sources of contamination to the canal; and determine the physical and chemical characteristics of the canal that would influence the development, evaluation and selection of cleanup alternatives. This work culminated in the development of a Remedial Investigation and Feasibility Study Report, which summarized the investigation findings and evaluated the feasibility of a range of potential remedies.

On December 27, 2012, EPA released a Proposed Remedial Action Plan (PRAP) describing its suggested remedy for the site. The PRAP recommended removing contaminated sediment that has accumulated as a result of industrial activity and sewer discharges from the bottom of the canal by dredging. In some locations, sediment would be permanently stabilized to prevent migration of contaminants. The dredged areas would then be capped. EPA also recommended controls to prevent combined sewer overflows (CSOs) and other land-based sources of contamination from compromising the cleanup.

The EPA accepted public comments regarding the Proposed Plan for a 90-day period. On January 23 and 24, 2012 EPA held public meetings to present the proposed plan and respond to questions and comments from attendees. More than 300 people attended the meetings.

After the public comment period ended the EPA issued a formal Record of Decision (ROD) selecting a remedy for the site on September 27, 2013. The Record of Decision included a Responsiveness Summary to comments and concerns received during the public comment period which were considered in the EPA’s final decision in the selection of a remedy to address the contamination at the site.

The EPA Community Involvement Plan can be accessed in the Document Library under the EPA Community Documents section, or by clicking here.

A Record of Decision (ROD), selecting a remedy for the site, was signed on September 27, 2013. The plan divides the canal into three segments, or Remediation Target Areas (RTA 1, 2 & 3). The first segment runs from the top of the canal at Butler Street to 3rd Street, the second segment from 3rd Street to just south of the Hamilton Avenue Bridge and the third segment runs from the Hamilton Avenue Bridge to the mouth of the canal. Approximately 300,000 cubic yards of contaminated sediment will be dredged from the first and second segments. For the third segment, approximately 281,000 cubic yards of contaminated sediment will be dredged. The plan also calls for removing contaminated material that was placed in the 1st Street Turning Basin decades ago and restoring about 475 feet of the former basin. The ROD also requires that a portion of the 5th Street Turning Basin underneath the 3rd Street bridge and extending about 25 feet to the east of the bridge be dredged and restored.

In dredged areas of the canal where contamination exists in the deeper native sediment, multiple layers of clean material will be placed to cap the contamination. The multilayer cap will consist of an “active” layer made of a specific type of clay and activated carbon that will remove contamination that could well up from below, an “isolation” layer of sand and gravel that will ensure that the contaminants are not exposed, and an “armor” layer of heavier gravel and stone to prevent erosion of the underlying layers from boat traffic and canal currents. Finally, sufficient clean sand will be placed on top of the “armor” layer to fill in the voids between the stones and to establish sufficient depth in order to restore the canal bottom as a habitat. In the middle and upper segments of the canal where the native sediment is contaminated with particular contaminants of concern, In-Situ Stabilization (ISS) will be employed. The stabilized areas will then be covered with the multiple layer cap as described above. The remedy relies on the control of upland sources of contamination to the canal, some of which are being addressed as an additional part of the Superfund cleanup, while others are being addressed through New York State’s Brownfields program. The ROD also calls for the construction of two CSO retention tanks in the upper canal to protect the integrity of the Superfund remedy that will be implemented in the canal.

The edges of the canal are supported by bulkheads that prevent the soil from eroding or collapsing into the waterway. In some areas, the existing bulkheads will be supported as a part of the cleanup to ensure the structural integrity of the canal banks while the dredging is taking place.

Dredging of RTA 1 began November 16, 2020.
The typical work week is from 7:00am to 5:30pm Monday through Thursday and until 3:30pm on Friday. Depending on weather and overall schedule, working Saturdays and Sundays, extended days, or second shifts are possible. Due to the complexities of outdoor construction and projects of this scope, schedules are subject to change.
A Record of Decision (ROD), selecting a remedy for the site, was signed on September 27, 2013, the plan divides the canal into three segments. The first segment runs from the top of the canal to 3rd Street, the second segment from 3rd Street to just south of the Hamilton Avenue Bridge and the third segment runs from the Hamilton Avenue Bridge to the mouth of the canal. The project staging site is located east of the corner of Smith Street and Huntington Street. Note: the staging area will be moving to a new location in December 2022.
There are three Remedial Treatment Areas (RTAs). Remediation of each area is projected to last up to 3 years. The overall cleanup is projected to last through 2030. Due to the complexities of outdoor construction, schedules are subject to change.
Dredged material is loaded onto small barges and transported down to the primary staging area (currently located at the intersection of Smith Street and Bay Street). At the staging area, water from the dredged material will be decontaminated onsite before being discharged back into the canal. The dewatered sediment will be transferred onto a larger barge and transported to an offsite facility, where the sediment will be processed and transformed into a beneficial-use product, such as landfill cover or otherwise disposed of. The current dredge material processing facility is the Claremont Clean Earth Facility in Jersey City, New Jersey.
After dredging, certain portions of the original bottom of the canal, or native sediment, will be solidified using concrete. These actions will be followed with the installation of a protective layer, also known as a cap. The dredging, solidification, and capping of the northern portion of the canal (RTA 1) is expected to continue through early 2024.

During dredging, it is common to remove other material that is not sediment from the canal. The vast majority of this material is usually identified as modern debris or timber. In accordance with archaeological protocols, outlined in the DRAFT Cultural Resources Plan (September 2020), items are screened from all dredged material and sorted.

Any items which are of potential archaeological or local significance are cleaned, placed in a holding area and cataloged for archaeological review. Please visit our Cultural Resources Page for information regarding items dredged from the canal.

During the cleanup activities, a series of monitoring stations will be set up to measure and record monitor air quality, noise, vibration, movement, and water quality. Environmental monitoring data will be available online at our Monitoring Data Page.

Dredging work in the canal will necessitate frequent bridge closures. Temporary traffic disruptions will occur at Union Street, Carroll Street, 3rd Street, 9th Street, and Hamilton Avenue during bridge closures. Extended closures of the bridges will occur during periods of heavy construction activity. For more details visit our Bridge Information page.

As we continue to adjust to the evolving COVID-19 situation, Gowanus Remediation Team is taking the necessary steps to ensure that decisions about cleanup activities at the Gowanus Canal Superfund site are made with the health and safety of the community and site workers as the priority. Moreover, our contractors are implementing health and safety plans specific to preventing the spread of the COVID-19 virus during cleanup activities. These plans require best practices for site safety, including face covering, gloves, and other appropriate personal protective equipment for employees and visitors, including temperature checks of employees, tracking employees who might be ill or have had contact with individuals testing positive for COVID-19, and social distancing. EPA will continue to monitor site operations and Gowanus Remediation Team’s health and safety practices.

Security includes fencing to restrict access at the staging site. GRT also has 24 Hour security present on the site and has installed cameras to monitor the project work area.

The nature of this work utilizes heavy civil, marine, construction equipment and methods to facilitate the remedy. As a result, at times, there will be noise levels that will be louder than neighbors experience on a typical day. As part of our monitoring program, GRT has deployed specialized equipment to ensure safe conditions. GRT continues to monitor these levels and will make every effort to notify the community in advance of significant events.

As a result of cleanup activities of this nature, neighbors and those in the area will experience odors from time to time. The GRT is monitoring air quality throughout the course of our daily work and has in place several protocols to rapidly and thoroughly address elevated concentrations of air quality levels. Our team monitors these levels throughout the workday and is alerted to changes in concentrations detected by a series of monitors so that appropriate action can be taken.

Parking restrictions are expected to be very limited. When they do occur, GRT will make every effort to inform neighbors in advance.

Huntington Street east of Smith Street will be closed for GRT staging until December 2022.

Our phone number has changed! As of March 2022, please dial (718) 569-5762 to share questions and comments with the Gowanus Remediation Team. You can also email or send us a message using the Contact Us page on our website.

There may be changes to public access for pedestrians and motorists who wish to travel across or near the canal during construction. Frequent bridge closures are needed for Gowanus Remediation Team (GRT) vessels and private construction vessels to traverse the canal. In order for a vessel to pass a bridge, the bridge must be opened and the corresponding roadway temporarily closed. Bridges may also be closed to roadway traffic for scheduled maintenance work. These bridge closures can cause delays and detours for roadway traffic.

The GRT is no longer utilizing the Huntington Street end east of Smith Street as a staging area.

There are restrictions on recreational boating activities as approved by the U.S. Coast Guard and local authorities.

Installed in 1911, the flushing tunnel is a large propeller that brings water into the Gowanus Canal from Buttermilk Channel (between lower Brooklyn and Governor’s Island through a brick-lined 1.2-mile (1.9-km) tunnel. Rehab of the tunnel began in 1994 and it was then reactivated in 1999. An upgrade began in 2010 and it was once again reactivated in 2014.

Certain remedial construction activities will require that the Flushing Tunnel be temporarily turned off. During the capping phases of the project, when clean material is placed along the bed of the canal, the Flushing Tunnel must be turned off to prevent scouring and displacement of clean material. Following the completion of capping material placement, an armor layer will be placed, and the Flushing Tunnel will be reactivated.

Capping material has been placed in the vicinity of the Flushing Tunnel but the armor mat to protect against scouring from Flushing Tunnel flow has not been placed. This armor mat layer is currently scheduled to be placed in November/December 2023, which will allow for reactivation of the Flushing Tunnel. Ceasing ongoing capping activities to allow for armor mat placement now would lead to significant delays in completion of the overall remedy.