What Happened to Passaic River?
The Passaic River, particularly its lower 17-mile stretch, is one of the most heavily polluted waterways in the United States, primarily due to decades of industrial waste dumping, including dioxin from Agent Orange manufacturing. Designated a Superfund site in 1984, the river is currently undergoing a complex, multi-billion dollar cleanup effort managed by the EPA, with significant portions still awaiting full remediation as of 2026.
Quick Answer
The Passaic River remains a major Superfund site, with ongoing, complex cleanup efforts focused on removing highly toxic sediments, particularly dioxin and PCBs. As of July 2026, the final engineering design for the lower 8.3 miles has been approved, and a protectiveness review for the former Diamond Alkali plant site was finalized in January 2026. However, the cleanup faces delays, corporate resistance to funding, and public demands for faster action, with strict fish and crab consumption advisories still in place.
📊Key Facts
📅Complete Timeline15 events
Industrial Revolution Pollution Begins
Early industrial development along the Passaic River, including cotton mills, tanneries, and dye works, began polluting the waterway with industrial residues.
Agent Orange Component Manufacturing and Dumping
Diamond Alkali Company in Newark manufactured Agent Orange, a herbicide, and illegally dumped significant quantities of chemical waste, including highly toxic dioxin, into the Passaic River. Monsanto also dumped PCBs.
Listed as Second Most Polluted River
The Passaic River was identified as the second most polluted river in America, highlighting the severe environmental degradation.
Dioxin State of Emergency
New Jersey declared a state of emergency after high levels of dioxin were found at the Givaudan Fragrances Corporation facility in Clifton, confirming another major source of contamination.
Lower Passaic River Designated Superfund Site
The EPA added the lower 17 miles of the Passaic River to the National Priorities List, designating it as part of the Diamond Alkali Superfund site due to high concentrations of hazardous substances.
Initial Cleanup at Lister Avenue Plant Completed
Cleanup work at the former Diamond Alkali manufacturing facility (Operable Unit 1) on Lister Avenue in Newark was completed, involving containment of contaminated soil and debris within a specially designed cell.
EPA Finalizes Cleanup Plan for Lower 8.3 Miles
The EPA released its Record of Decision for the lower 8.3 miles of the Passaic River, outlining a plan to dredge 3.5 million cubic yards of contaminated sediment and cap the riverbed at an estimated cost of $1.38 billion.
Federal Agencies Launch Natural Resource Damage Assessment Plan
NOAA and the U.S. Fish and Wildlife Service released a final Natural Resource Damage Assessment Plan for the Diamond Alkali Superfund Site to study the impact on wildlife and recover damages from responsible parties.
Final Engineering Design for Lower River Approved
Federal authorities approved the final engineering design for the lower 8.3 miles of the river, including plans to dredge approximately 2.5 million cubic yards of contaminated sediment and cap the riverbed.
Settlement with 85 Responsible Parties Announced
The Department of Justice and EPA announced a proposed consent decree with 85 potentially responsible parties, requiring them to pay $150 million towards the cleanup of the Lower Passaic River.
Natural Resources Park Opens
BASF funded the design and construction of a 5-acre natural resources park on the Passaic River in East Newark, which opened to the public, with BASF also providing 30 years of stewardship and maintenance.
EPA Finalizes Protectiveness Review for Lister Avenue Site
The EPA completed its Sixth Five-Year Review of the Diamond Alkali Superfund Site's Operable Unit 1 (80-120 Lister Avenue), confirming that the cleanup remains protective of human health and the environment.
Updated Fish Consumption Advisories Issued
The NJDEP issued updated 'Fish Smart, Eat Smart' advisories, maintaining strict warnings for the Passaic River, including a complete ban on harvesting blue crabs from the Newark Bay Complex and tidal Passaic River due to contaminants.
Newark Protesters Demand Cleanup Action
Activists with the Ironbound Community Corporation rallied at Riverfront Park in Newark, demanding more action on the long-stalled cleanup of the Diamond Alkali Superfund site.
Passaic River Community Advisory Group Meeting
The Passaic River Community Advisory Group (CAG) held a meeting in Newark to discuss ongoing cleanup efforts and community engagement.
🔍Deep Dive Analysis
The Passaic River, flowing approximately 80 miles through northern New Jersey, has a long history of industrial development that led to severe contamination, particularly in its lower 17-mile tidal stretch from Dundee Dam to Newark Bay. Early pollution began with textile mills and other industries in the 1800s, but the most egregious contamination occurred from the mid-20th century.
A primary source of this pollution was the Diamond Alkali Company's plant in Newark, which between 1951 and 1969, manufactured Agent Orange, a defoliant used in the Vietnam War. The plant illegally dumped manufacturing byproducts, including highly toxic dioxin (2,3,7,8-TCDD), directly into the river. Other significant polluters included Givaudan Corporation, also a major source of dioxin, and Monsanto Company, which dumped PCBs. This legacy of contamination led the U.S. Environmental Protection Agency (EPA) to designate the lower Passaic River as part of the Diamond Alkali Superfund site in 1984, making it one of the nation's largest and most complex hazardous waste cleanups.
The cleanup plan for the lower 8.3 miles of the river, finalized by the EPA in 2016, involves dredging approximately 3.5 million cubic yards of contaminated sediment and then placing an engineered cap over the riverbed. The estimated cost for this portion of the cleanup alone is $1.38 billion. Occidental Chemical Corporation, through its subsidiaries Glenn Springs Holdings and Environmental Resource Holdings (ERH), has been identified as responsible for approximately 98% of the cleanup costs and is managing the detailed remedial design work. In February 2025, the Department of Justice and EPA announced a proposed consent decree with 85 other potentially responsible parties, requiring them to pay $150 million to support cleanup efforts.
As of July 2026, the cleanup is ongoing but faces significant challenges. Environmental activists, such as the Ironbound Community Corporation, protested in June 2026, demanding faster action on the stalled cleanup of the Diamond Alkali Superfund site. While the final engineering design for the lower 8.3 miles was approved in 2024, and the EPA completed a protectiveness review for the former Lister Avenue plant site (Operable Unit 1) in January 2026, active dredging and capping for the main river stretch have not yet commenced. Furthermore, a 2025 report highlighted corporate resistance to paying for major components and potential federal budget cuts in the 2026 budget as threats to progress. Fish and crab consumption advisories, including a ban on harvesting blue crabs from the Newark Bay Complex and tidal Passaic River, remain strictly in effect as of March 2026 due to persistent levels of dioxin, PCBs, and mercury.
What If...?
Explore alternate histories. What if Passaic River made different choices?