EPA Superfund site
DIAMOND ALKALI CO.
Human exposure is NOT currently under control
Data limitations: Proximity to a Superfund site boundary does not mean your property is contaminated. EPA site boundaries show the area designated for cleanup, not the full extent of contamination. Groundwater plumes can extend beyond site boundaries. This tool shows publicly available EPA federal data. It is not affiliated with or endorsed by EPA, and is not a substitute for a professional environmental assessment.
About this site's exposure pathways
As of May 2026, the Diamond Alkali Superfund site is considered “Current Human Exposure Not Under Control” (HENC). Residents and recreational anglers are known to be exposed by eating fish and shellfish caught from the lower Passaic River and Newark Bay. The New Jersey Department of Environmental Protection (NJDEP) has issued fish and shellfish consumption advisories for these waters based on contamination with polychlorinated biphenyls (PCBs), dioxins, and mercury.
Currently, the planned activities to address this pathway include: continuing to implement the remedy for the lower 8.3 miles of the Passaic River; designing and implementing the interim remedy for the upper 9 miles; and implementing the final remedy at the former Diamond Alkali facility. EPA will also continue working with NJDEP and local partners to maintain and post fish consumption advisory signage, conduct long-term sediment, water and biota monitoring, and maintain institutional controls.
If you may be affected, you can reduce your exposure by not eating fish or shellfish caught from the lower Passaic River or Newark Bay, practicing catch-and-release, and following posted signs and NJDEP advisories. For more information, contact the EPA Community Involvement Coordinator Drew Curtis via the site webpage or at (212) 637-3726 or [email protected].
EPA currently anticipates that human exposure will be under control by August 2057 because the 80-120 Lister Avenue, Lower Passaic River and Newark Bay remedies are expected to be completed, institutional controls will be fully implemented, and long‑term monitoring is expected to show sediment, water and fish tissue levels making substantial progress toward meeting risk‑based cleanup goals by that time.