How the Passaic River Shaped New Jersey's Industrial History

Quick Answer

The Passaic River has been central to New Jersey's industrial growth, its environmental decline, and its ongoing recovery since the 19th century. Its waters powered factories, supported transportation, and ultimately became contaminated by industrial waste, leading to one of the largest Superfund site efforts in the nation.

Current cleanup operations continue through 2026, while flood control and water quality management remain critical challenges for surrounding communities.

Key Facts

• The Lower Passaic River is part of the Diamond Alkali Superfund site, with cleanup managed by Glenn Springs Holdings, Inc., an Occidental subsidiary, and Environmental Resource Holdings, LLC, which retained environmental liabilities when OxyChem was sold in early 2026.
• The EPA finalized a plan in 2025 to clean up the 80-120 Lister Avenue property in Newark, part of ongoing remediation efforts.
• Two cleanups of the river have been completed, with a third bank-to-bank cleanup plan for the lower eight-mile stretch issued in March 2016.
• The Passaic was named one of America's Most Endangered Rivers of 2025.
• Water quality monitoring continues through the Passaic Valley Water Commission, which published its 2024 Drinking Water Quality Report based on data collected during 2023.
• Flood control efforts include a 15-point plan developed by the Passaic River Flood Advisory Commission, covering buyouts, improved stormwater management, and redevelopment designs to reduce flood damage risks.
• One proposed flood mitigation option is a diversion tunnel costing $4.7 billion with a benefit-to-cost ratio of 1.05; a 10-year nonstructural option costs $1.2 billion with a ratio of 2.1.

The River That Built an Industrial Empire

The Passaic River flows approximately 80 miles through northern New Jersey, draining a watershed of nearly 935 square miles before emptying into Newark Bay. Its journey from the hills of Morris County to the industrial heartland of Paterson, Passaic, and Newark tells a story of transformation that mirrors American industrial history itself.

In the late 18th and early 19th centuries, the Passaic's waterfalls—particularly the Great Falls of Paterson—became the engine of America's industrial revolution. The falls, with a 77-foot drop, provided reliable water power that attracted Alexander Hamilton's Society for the Establishment of Useful Manufactures in 1791.

This decision turned Paterson into one of the nation's first planned industrial cities. By the mid-1800s, the river powered textile mills, locomotive factories, and silk production facilities that employed tens of thousands of workers.

The river's geography made it ideal for industry. Its relatively steep gradient in the upper reaches provided consistent water flow, while the lower sections offered navigable channels for shipping goods to New York City and beyond.

Industrialists built along its banks in a dense corridor stretching from Paterson through Passaic, Clifton, and into Newark. By the early 20th century, the Passaic River watershed hosted chemical plants, metal finishing facilities, and dye manufacturers that produced everything from textiles to munitions.

This industrial growth came with an environmental cost that would not be fully understood for generations. Factories discharged waste directly into the river with minimal treatment.

The same water that powered mills also received their chemical byproducts, heavy metals, and organic pollutants. For decades, this was considered normal—the cost of economic progress in an era before environmental regulations.

The Toxic Legacy Understanding the Contamination Crisis

How Industrial Pollution Accumulated

The Passaic River's contamination story is not one single event but a century-long accumulation of industrial discharge. The Diamond Alkali Company facility in Newark, which operated from 1916 to 1969, produced chemicals including the herbicide Agent Orange used during the Vietnam War.

This facility became the epicenter of the river's pollution crisis, releasing dioxin and other persistent organic pollutants into the water and sediments. The contamination did not stay in one place.

Tidal action in the lower eight miles of the river pushed pollutants back and forth, spreading them across a wide area. Heavy metals from metal plating facilities, PCBs from electrical equipment manufacturers, and pesticides from agricultural runoff all accumulated in the river's sediments.

By the 1960s and 1970s, the Passaic had become one of the most polluted waterways in the United States.

The Superfund Designation and Cleanup Timeline

The Environmental Protection Agency took action by designating the Lower Passaic River as part of the Diamond Alkali Superfund site. This designation triggered a multi-decade cleanup process that continues through 2026.

The cleanup is structured in phases, reflecting both the complexity of the contamination and the practical challenges of remediating an urban river. Two cleanups have been completed to date.

The first addressed the most contaminated hotspots, removing highly concentrated dioxin and other pollutants from specific areas. The second cleanup expanded the remediation footprint.

In March 2016, the EPA issued a plan for a third cleanup—a bank-to-bank removal for the lower eight-mile stretch of the river. This phase aims to remove contaminated sediment across the entire width of the river channel, rather than targeting only the most polluted areas.

Cleanup management is handled by Glenn Springs Holdings, Inc., a subsidiary of Occidental Petroleum Corporation. Glenn Springs is described in current sources as a "highly regarded" operator for its work on complex environmental remediation projects.

In early 2026, when Occidental sold its OxyChem business, Environmental Resource Holdings, LLC retained the environmental liabilities associated with the Passaic River cleanup. This structure ensures that the financial responsibility for the cleanup remains with entities capable of funding the long-term work.

Current Status in 2026

As of July 2026, cleanup operations are in progress on the Lower Passaic River. The EPA continues to oversee the work, with monitoring and management of environmental restoration efforts ongoing.

The 2025 designation of the Passaic as one of America's Most Endangered Rivers highlighted both the progress made and the work remaining. The cleanup timeline extends several more years into the future.

Dredging operations remove contaminated sediment, which is then processed and disposed of at permitted facilities. Habitat restoration follows the dredging, with native plants and structures designed to support fish and wildlife populations.

The entire process is complicated by the river's urban setting—the cleanup must proceed around bridges, utility lines, and other infrastructure while minimizing disruption to communities along the river.

Water Quality and Flood Control Twin Challenges

Drinking Water Safety

The Passaic River serves as a drinking water source for hundreds of thousands of New Jersey residents. The Passaic Valley Water Commission (PVWC) is responsible for treating and distributing this water.

Its 2024 Drinking Water Quality Report, based on data collected during 2023, provides transparency about what comes out of taps in the region. The report details compliance monitoring results for a range of contaminants.

For calendar year 2023, the PVWC collected and analyzed water samples for bacteria, heavy metals, organic compounds, and disinfection byproducts. The report format follows federal requirements under the Safe Drinking Water Act, making the data accessible to the public.

While the reference material does not include specific detection levels or violation records, the existence of public reporting mechanisms demonstrates the ongoing commitment to water safety in the region. Additional monitoring occurs through the Water Quality Portal, which includes data from the USGS for the Passaic River at Totowa Road.

This sampling site provides information about the river's condition before water reaches treatment facilities. Recent data added since March 11, 2024, helps track changes in water quality over time.

PFAS Contamination An Emerging Concern

The 2024 Water Quality Report Card from the Great Swamp Watershed Association includes a spotlight on PFAS contamination in local streams. PFAS—per- and polyfluoroalkyl substances—are a class of chemicals used in non-stick coatings, firefighting foams, and industrial processes.

They are persistent in the environment and have been linked to health effects in humans. The presence of PFAS in Passaic River tributaries represents a newer dimension of the water quality challenge.

Unlike legacy pollutants such as dioxin and PCBs, which have been subject to regulation for decades, PFAS are only now receiving increased regulatory attention. The EPA has established health advisory levels for certain PFAS compounds, and water utilities across the country are investing in treatment technologies to remove them.

For the Passaic River watershed, PFAS contamination likely originates from multiple sources: industrial discharges, landfills, and the historical use of firefighting foams at airports and military facilities within the watershed. Monitoring efforts by organizations like the Great Swamp Watershed Association help identify hotspots and track trends over time.

The Flooding Crisis

The Passaic River has a long history of flooding, with major events causing significant damage to communities in Morris, Essex, and Passaic counties. The river's watershed collects rainfall from a large area, and development in floodplains has increased the damage potential when waters rise.

In January 2024, the Passaic River at Little Falls was projected to rise to 21.9 feet, resulting in major flooding in surrounding townships. This event underscored the ongoing risk faced by communities along the river.

The National Water Prediction Service provides real-time monitoring through gauges at Pine Brook, Little Falls, and other locations, allowing emergency managers to issue warnings and coordinate responses. The Passaic River Flood Advisory Commission issued a 15-point plan to mitigate flood impacts in Morris County and surrounding areas.

Key elements of this plan include:

• Buyouts of homes at greatest risk of flooding, permanently removing structures from flood-prone areas
• Improved stormwater management to reduce neighborhood flooding from intense rainfall events
• Redevelopment designs that reduce flood damage risks, such as elevating buildings and using flood-resistant materials
• Flood-proofing of existing buildings in flood-prone areas
• Robust flood warning and preparedness systems that give residents time to evacuate
• Improved post-flood response programs to speed recovery
• Improved transportation corridors to ensure emergency access across flooded areas
• Municipal involvement in FEMA's Community Rating System, which can reduce flood insurance premiums for residents

The Passaic River Coalition supports stringent development controls in flood zones, arguing that continued building in flood-prone areas exacerbates both the frequency and severity of flood damage. The coalition advocates for policies that prioritize open space, wetlands preservation, and natural flood storage over development.

Economic analysis of flood mitigation options reveals difficult tradeoffs. A proposed diversion tunnel would cost approximately $4.7 billion with a benefit-to-cost ratio of 1.05, meaning the benefits barely exceed the costs.

In contrast, a 10-year nonstructural option—focusing on buyouts, flood-proofing, and improved warning systems—would cost $1.2 billion with a benefit-to-cost ratio of 2.1, making it significantly more cost-effective. This analysis, provided to the New Jersey Department of Environmental Protection, informs policy decisions about how to allocate limited resources for flood mitigation.

The Human and Economic Dimensions

Communities Affected

The Passaic River runs through a densely populated region with significant economic and racial diversity. Lower-income communities and communities of color have historically borne a disproportionate share of the pollution burden.

The Diamond Alkali site in Newark's Ironbound neighborhood sits adjacent to residential areas, meaning that cleanup progress directly affects public health for nearby residents. The Urban Waters partnership between the EPA and local organizations aims to connect communities with the river.

This program supports environmental education, job training in green industries, and community-based monitoring efforts. By engaging residents in the restoration process, the partnership builds local capacity to advocate for continued cleanup and prevention of future pollution.

Economic Impact of Cleanup and Flooding

The Passaic River cleanup represents a massive economic investment. The total cost of the Superfund remediation runs into the billions of dollars, with Occidental Petroleum funding the work through its subsidiaries.

While expensive, the cleanup also creates economic activity—dredging operations require workers, equipment, and disposal services, providing jobs in the region. Flooding imposes its own economic costs.

Each major flood event damages homes, businesses, and infrastructure, requiring expensive repairs and disrupting economic activity. The 15-point flood mitigation plan recognizes that spending money on prevention is more cost-effective than repeatedly paying for recovery.

The benefit-to-cost analysis of nonstructural options supports this conclusion, showing that investments in buyouts and flood-proofing yield returns through reduced damage. Property values along the river reflect both the amenity value of water access and the risks of flooding and contamination.

As cleanup progresses and flood mitigation improves, property values may increase, benefiting homeowners and local tax bases. However, this creates a tension—rising property values can make buyout programs more expensive and can price out long-term residents.

The Role of Advocacy Organizations

The Passaic River Coalition has been a consistent voice for environmental protection and smart development in the watershed. Its advocacy for stringent development controls in flood zones reflects a long-term perspective that prioritizes public safety and ecological health over short-term development gains.

The coalition's involvement in Superfund oversight ensures that community voices are heard in cleanup decisions. The Great Swamp Watershed Association contributes through scientific monitoring and public education.

Its water quality report cards provide accessible information about the health of streams in the Passaic River watershed. The focus on PFAS contamination in recent report cards shows how the organization adapts to emerging threats.

The Path Forward What Happens Next

Cleanup Timeline and Milestones

The Lower Passaic River cleanup is expected to take several more years. The third phase of bank-to-bank dredging in the lower eight miles is the most complex and expensive component.

Following dredging, habitat restoration will reconstruct wetlands, plant native vegetation, and create structures that support fish and wildlife. The 2025 EPA plan for the 80-120 Lister Avenue property in Newark represents a specific milestone.

This property, part of the Diamond Alkali Superfund site, will undergo continued operations as outlined in the final cleanup plan. The exact nature of these operations—whether they involve soil removal, capping, or other remediation techniques—is determined by site-specific conditions and regulatory requirements.

Climate Change and Future Challenges

Climate change introduces additional uncertainty into the Passaic River's future. More intense rainfall events, driven by a warming atmosphere, increase flood risks.

Sea level rise in Newark Bay pushes tidal waters higher, potentially affecting drainage and contaminant transport in the lower river. The flood mitigation strategies outlined in the 15-point plan must account for these changing conditions.

Buyout programs that remove homes from the floodplain become more attractive as flood risks increase. Stormwater management systems need to handle larger volumes of water during extreme events.

The benefit-to-cost analysis of flood mitigation options may shift over time as climate projections become more certain and flood damages increase.

Water Quality Monitoring Going Forward

The PVWC will continue to publish annual water quality reports, providing transparency about drinking water safety. The 2024 report based on 2023 data sets a baseline for ongoing monitoring.

Future reports will track trends in contaminant levels and treatment effectiveness. The emergence of PFAS as a priority contaminant will likely lead to additional monitoring requirements and treatment investments.

Water utilities across New Jersey are evaluating granular activated carbon filtration, ion exchange, and reverse osmosis as PFAS removal technologies. The cost of these upgrades may be significant, but public health benefits are expected to justify the investment.

Frequently Asked Questions

What is the current status of the Passaic River cleanup in 2026?

Cleanup of the Lower Passaic River is in progress under Glenn Springs Holdings, Inc., an Occidental subsidiary. The EPA oversees the work, which includes dredging contaminated sediment and restoring habitats.

The cleanup is expected to take several more years, with the third bank-to-bank phase in the lower eight miles being the most extensive component.

Is the Passaic River safe for drinking water?

The Passaic Valley Water Commission treats water from the river to meet federal drinking water standards. Its 2024 Drinking Water Quality Report, based on 2023 data, provides public information about compliance monitoring.

While the river itself remains contaminated with industrial pollutants in its sediments, treated drinking water is monitored and regulated for safety.

What caused the contamination in the Passaic River?

Industrial discharges from the early 20th century through the 1960s and 1970s caused the contamination. The Diamond Alkali Company facility in Newark, which produced chemicals including Agent Orange, was a major source of dioxin.

Metal plating facilities, chemical plants, and other industries contributed heavy metals, PCBs, and other pollutants that accumulated in river sediments.

How does flooding affect communities along the Passaic River?

Flooding causes major damage to homes, businesses, and infrastructure in communities along the river. The Passaic River Flood Advisory Commission issued a 15-point plan addressing buyouts, improved stormwater management, flood-proofing, and warning systems.

One proposed mitigation option is a $4.7 billion diversion tunnel, while a $1.2 billion nonstructural approach has a higher benefit-to-cost ratio.

What is being done about PFAS contamination in the river?

The Great Swamp Watershed Association's 2024 Water Quality Report Card highlights PFAS contamination in local streams. Monitoring efforts are identifying PFAS hotspots, and water utilities are evaluating treatment technologies to remove these compounds.

PFAS are an emerging concern that may require additional regulatory action and treatment investments.

Reference Notes

Information in this article is based on publicly available sources including EPA documents, the Passaic Valley Water Commission, the Passaic River Coalition, the Great Swamp Watershed Association, and national water monitoring databases. Some details, particularly regarding specific contaminant levels and cleanup timelines, may change over time.

Verify with official sources such as the EPA's Lower Passaic River Superfund site page and the Passaic Valley Water Commission before acting on this information.