Brunswick Facility

EPD re-issued the hazardous waste permit for the Brunswick facility in November 2020. Despite its name, the new “hazardous waste permit” reflects the fact that neither Hercules nor Pinova is storing hazardous waste at the Brunswick facility as was done in the past. In January 2022, Hercules submitted to EPD a revised Corrective Action Plan (“CAP”) for comprehensive remediation of the Brunswick facility that took into account feedback received from EPD and the public during 2021’s public review process. During the past two years, Hercules remediated soil and groundwater and made building improvements to prevent vapor intrusion that will help pave the way for implementation of the CAP after it is approved by EPD.

What’s been done and what’s next

Since the 1980s, Hercules remediated more than 50,000 tons of potentially contaminated soil at the Brunswick facility and actively remediated groundwater sources on-site. In 2021, Hercules remediated soil in several areas and installed vapor intrusion mitigation systems at various buildings on-site. In 2022, Hercules obtained EPD’s approval of its revised CAP. Across 2022 and 2023, Hercules implemented three groundwater remediation plans. Implementation of the CAP will continue in 2024 and beyond.

Soils

In 2021, Hercules removed substantial amounts of soil and waste from the former toxaphene tank farm area.

Also in 2021, Hercules completed an “in-situ solidification” remedy for soils impacted by toxaphene. The remedy creates a solid, weather-resistant block that solidifies the soils in place to prevent future exposure while also preparing the area to be potentially reused.

Hercules has remediated more than 50,000 tons of contaminated or potentially contaminated soils at the site.

The CAP explains how Hercules will identify additional areas of soils to be remediated and the technologies that will be available to be deployed as necessary. In 2022, Hercules submitted a plan to describe additional site-wide soil remediation at the facility. The EPD-approved plan was implemented in July 2023.

Groundwater

Hercules investigates and monitors groundwater at the Brunswick facility and off-site areas through a monitoring well network consisting of more than 100 monitoring wells. The network will be modified or expanded as more is learned about environmental impacts. The impacts caused by historical activities at the Brunswick facility are generally limited to the upper surficial aquifer — roughly the first 100 feet below the ground surface. This impacted groundwater does not pose a risk to human health because no one in the area drinks water sourced from the surficial aquifer. With the ocean and tidal creeks so near the Brunswick facility, water in the eastern portions of the Brunswick facility surficial aquifer is brackish and would have an unpleasant taste. People in the area rely on water from the Upper Floridan aquifer, which lies hundreds of feet below the impacted groundwater zone. In 2022, Hercules confirmed that the few private water supply wells located on Terry Creek Road (east of the facility) withdraw water from the Floridan aquifer, which is not affected by the facility. However, two of these wells were replaced as a conservative measure of protection.

Thick layers of clay, called “confining units,” separate the various aquifers and prevent contamination near the surface from reaching deeper aquifers. The Upper Floridan aquifer is at least 500 feet below the ground surface.

Layers of Water and Rock beneath Brunswick

Depiction of the aquifers beneath the Brunswick area and the units that confine groundwater movement. — *Depiction of the aquifers beneath the Brunswick area and the units that confine groundwater movement*.

Hercules has nevertheless implemented three different EPD-approved groundwater treatment plans since 2021. The plans address on-site and off-site groundwater to the east of the facility. In 2023, Hercules expects to implement the third groundwater treatment plan, addressing groundwater to the east and northeast of the site. Going forward, Hercules will continue its on- and off-site monitoring of groundwater in the upper surficial aquifer to confirm the effectiveness of these remedies and to understand any potential changes in conditions.

Vapor Intrusion

In the last few years, Hercules performed a comprehensive assessment of possible vapor intrusion at all buildings at the Brunswick facility. Hercules worked with EPD to evaluate and make adjustments to any buildings where vapor intrusion posed a potential concern. Hercules completed this work in 2022. EPD approved the building modifications and is completing a review of the vapor intrusion evaluation for the entire site.

All of Hercules’ work was performed in accordance with technical guidelines issued by EPA and EPD and under the oversight of EPD and EPA, as appropriate.