EPA Press Office:

EPA Orders Occidental Chemical Corp. to Design Cleanup Plan for the Upper Nine Miles of the Lower Passaic River at the Diamond Alkali Superfund Site in New Jersey

NEW YORK (March 2, 2023) - Today, the U.S. Environmental Protection Agency (EPA) issued an administrative order requiring Occidental Chemical Corp. (OxyChem) to design the interim cleanup plan that EPA selected in September 2021 for the upper nine miles of the Lower Passaic River Study Area of the Diamond Alkali Superfund site in New Jersey. OxyChem will be responsible for preparing work plans and conducting a preliminary investigation. This includes sampling to identify contamination boundaries. OxyChem will also conduct studies to assess the river bottom, shoreline, and other aspects of the river in preparation for the cleanup.

“Under this order, OxyChem will perform the engineering work needed before the actual cleanup work can begin,” said Regional Administrator Lisa F. Garcia. "EPA will closely monitor this work, which is a critical step towards restoring this iconic river for the communities along its banks."

The Diamond Alkali Superfund site includes the lower 17 miles of the Passaic River. The majority of the contaminated sediment is in the lower 8.3 miles, but the contamination in the upper nine miles continues to impact the river's ecosystem and surrounding communities. In September 2021, EPA finalized a cleanup plan that involved removing or isolating the contamination sources under a cap. This cleanup work is planned to coincide with the cleanup of the lower 8.3 miles of the river. OxyChem is designing the lower portion's cleanup plan and will perform the upper nine-mile design. Following EPA approval, the final design report will include site-wide monitoring plans, health and safety plans, and provide a detailed outline of the cleanup plan, including specific details on how the cleanup will be conducted.

The cleanup plan that OxyChem will be designing is an interim action, meaning that when the cleanup has been completed, EPA will evaluate the results and may determine that further work is necessary to address any remaining contamination in this section of the river. The cleanup plan includes the following:

• Capping and dredging of approximately 387,000 cubic yards of contaminated sediment.
• Prior to capping, sediment will be dredged to a depth to accommodate the cap so that the potential for flooding is not increased.
• Additional capping and dredging in areas with the potential for erosion and high concentrations of contaminants in the subsurface.
• Evaluating areas where sediments can be dredged so that capping would not be needed.
• Processing dredged materials at one or more nearby sediment processing facilities.
• Restricting activities in the river to protect the cap, and the continuation of New Jersey's existing prohibitions on fish and crab consumption.
• Monitoring and maintaining the cap to ensure its stability and integrity in the long term.

Background

EPA often divides cleanup activities at complex sites into different areas or operable units (OUs): The Diamond Alkali Superfund site is currently organized into four OUs.

• OU1 is the location of the former Diamond Alkali pesticide manufacturing plant at 80-120 Lister Avenue, for which an interim cleanup for containment was completed in 2001.

• OU2 is the lower 8.3 miles of the Lower Passaic River, from Newark Bay to river mile 8.3, for which EPA selected a cleanup in 2016. The estimated $1.38 billion cleanup plan is currently in remedial design under EPA oversight.

• OU3 is the Newark Bay Study Area. EPA is currently overseeing an in-depth investigation of the bay, including the nature and extent of the contamination and the potential risks to human health and the environment from exposure to this contamination, and an evaluation of technologies and alternatives in order to determine how best to clean it up over the long term.

• OU4 is the 17-mile Lower Passaic River Study Area which includes both the lower 8.3 miles of the River and the upper nine miles. This administrative order covers design work for cleanup of the upper nine miles of OU4 in the Lower Passaic River Study Area which is an interim action. When the cleanup work has been completed, EPA will evaluate conditions in the river, determine if further work is needed, and document the decision in a final decision document.

Visit the Diamond Alkali Co. Superfund site profile page for additional background and site documents.

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For further information: Elias Rodriguez, rodriguez.elias@epa.gov, (212) 637-3664