Koppers Co., Inc. (Newport Plant)

Overview

The Koppers Co., Inc. Newport Plant is a 300-acre former wood-treating facility in Newport, Delaware. It operated from 1929 to 1971, using creosote and coal tar to preserve railroad ties, telephone poles, and other wood products. Spills, leaks, and waste handling during those decades contaminated soil, sediment, surface water, and groundwater. EPA added the site to the Superfund National Priorities List in August 1990.

The main contaminants are polycyclic aromatic hydrocarbons, or PAHs, which are constituents of creosote. In some areas, liquid creosote exists in a non-aqueous phase liquid form, meaning it does not mix with water and pools separately underground. EPA has also identified 166 total contaminants of concern across soil, groundwater, and sediment, including heavy metals such as lead, arsenic, and mercury, volatile organic compounds like benzene and toluene, pesticides including DDT and dieldrin, and phthalates. Dioxin toxicity equivalents appear in both soil and groundwater. PAHs pose ecological risks to upland, wetland, and aquatic species, including those in the nearby creek and marsh areas.

EPA issued a cleanup plan in a 2005 Record of Decision. That plan called for excavation, engineered capping, a subsurface groundwater barrier wall, free product recovery, pump-and-treat systems, wetlands mitigation along Hershey Run, and institutional controls. The remedy was updated in August 2022 with a Record of Decision Amendment that added soil monitoring, vertical engineered barriers, stream realignment, and solidification and stabilization of materials onsite. EPA currently considers short-term human exposure pathways to be under control and has confirmed that contaminated groundwater migration is stabilized, posing no unacceptable discharge to surface water.

As of the most recent updates, EPA approved a pre-design investigation work plan in October 2024 to fill data gaps before full remedial design begins. Field investigation activities started in March 2025 and are expected to run through spring 2026. Remedial design is projected to continue through 2027, with remedial action potentially beginning in 2028. Physical construction has not yet started, and the site is not ready for unrestricted use.

Community members can consult the August 2022 Community Involvement Plan for details on how to participate in the cleanup process. A pre-recorded video about the proposed cleanup was made available in place of an in-person public meeting. The March 2021 Community Update Fact Sheet also summarizes the cleanup plan. Public records are available at the Delaware Department of Natural Resources and Environmental Control in New Castle, Kirkwood Public Library in Wilmington, and the EPA Region 3 office in Philadelphia.