TERRY CREEK
Hercules removed approximately 85-percent of the toxaphene from the Terry Creek outfall ditch and portions of Dupree and Terry Creeks in 1999 and 2000. EPA’s additional remedy, selected in 2017, builds on this work by capping the outfall ditch and rerouting the flow. The remedy effectively isolated residual toxaphene remaining in the outfall ditch so that it does not present a potential risk to the environment or human health.
Monitoring fish tissue, Back River (2017)
EPA selected the interim remedy after extensive studies were conducted under the federal Superfund process, with the concurrence of EPD. The plan can be found on EPA’s website. Implementation of the remedy involved capping and filling the former outfall channel while redirecting stormwater flow to a newly constructed, state-of-the-art stormwater channel.
Since fish caught in Terry Creek waters were first tested in 1997, the quality of fish tissue has improved steadily, largely due to the removal actions undertaken by Hercules and overseen by EPA. This improvement is reflected in relaxed state guidelines for fish consumption. Remedial actions completed in Terry Creek and at the Brunswick facility resulted in fewer restrictions on fish consumption as shown in the graph below.
*Silver perch - Brunswick facility not likely source of restriction
The completion of the EPA’s selected interim remedy in 2025 effectively prevents the outfall ditch from contributing to downstream contamination, while also promoting future site redevelopment.
The first round of testing in a long-term monitoring plan has confirmed the remedy is working. EPA will continue to determine if further actions are needed. Other portions of the Terry Creek site will be investigated and remediated as needed under the Superfund program, with investigations for the creeks and other areas beginning in late 2025.
Toxaphene does not dissolve in water and is not a groundwater contaminant at the Terry Creek site or at adjacent properties. Ongoing groundwater evaluations overseen by EPD support these conclusions. Nearby drinking water wells have been tested, and neither toxaphene nor volatile organic compounds have been detected in the well water.
Outfall Ditch Remedy
As part of the approved remedy for Terry Creek, a new concrete-block stormwater conveyance channel has been built from the Brunswick plant to Dupree Creek, and the old outfall ditch has been filled and capped. Construction of the remedy was completed in July 2025.
Aerial photo from 2023 when construction on the new channel had just begun.
Aerial photo from August 2025 with grass beginning to grow over the cap atop the former Outfall Ditch.
What’s next
With the completion of the outfall ditch capping and construction of the new channel, Hercules is now focused on the investigation of soils and sediments in Dupree and Terry Creeks, including the areas where the U.S. Army Corps of Engineers historically placed dredged spoils. The investigation will help Hercules and the EPA understand remedial options for these areas.
Field crews sample the marsh (2025)