Protecting Human Health and the Environment

About the Former Tronox/Kerr-McGee Facility

The former Tronox/Kerr-McGee Wood Treating Facility in Springfield, Missouri (the Facility) was contaminated from almost 100 years of wood treating operations by Kerr-McGee and its predecessors. Primary contaminants include dense nonaqueous phase liquid (DNAPL) as creosote, naphthalene, and BTEX compounds (benzene, toluene, ethylbenzene, and xylene).

In 2002, the MoDNR and EPA approved a final remedy for the Facility that required both post-closure care (PCC) and corrective actions. PCC involves long-term maintenance of the closed hazardous waste surface impoundments and land farm, and corrective actions include operating the Facility’s groundwater treatment system to hydraulically control groundwater and recover creosote. The PCC and corrective actions ensure that residual contamination from the Facility is not continuing to migrate and pollute the environment. When the Multistate Trust assumed ownership of the Facility in 2011, it also took over the Missouri Hazardous Waste Management Facility (MHWMF) Part I Permit requirements, including continued environmental investigations.

Extensive karst features, such as voids, caverns, and sinkholes, exist in the shallow bedrock under the Springfield area, and many springs surface at points around the Facility. These karst features provide underground pathways for groundwater contamination to potentially travel farther than it would in other environments. Groundwater contamination is therefore difficult to fully characterize in karst settings, as groundwater flow does not often follow a predictable pattern. This complicates the evaluation of contamination plumes and DNAPL migration.

Overview of Investigations and Remediation Progress

Milestones Achieved to Date

Between 1976 and 2011, investigations and remediation around the Facility was performed by Kerr-McGee (and later Tronox), as required by EPA and the MoDNR.
Major work included:

  • Installing and operating a treatment system to capture contaminated groundwater and recover DNAPL

  • Closing three lagoons that were designated Hazardous Waste Management Units

  • Establishing a land farm to treat creosote-contaminated soil

  • Installing and sampling from groundwater monitoring wells (on- and off-Facility)

  • Investigating groundwater to find a connection between Vich Spring and contaminant releases from the Facility

Since assuming responsibility for the Facility in 2011, the Multistate Trust has implemented and completed numerous environmental actions and investigations at and around the Facility, including:

  • Soil sampling for Greene County Highway Department’s (GCHD) Northwest Stormwater Basin, June 2021

  • Domestic well sampling (results shared with individual residents), 2021

  • GCHD site investigation activities and reporting, 2021

  • Renewal of the MHWMF Part I Permit, 2020

  • Surface water sampling from Woodlawn Spring, 2019 – Present

  • Vapor intrusion investigations and reporting, June 2017 – January 2019

  • Residential property sampling (results shared with individual residents), 2017 – present

  • Remedial Action Optimization (RAO) work planning, field work and reporting, August 2016 – October 2017

  • Recovery Well Evaluation and Site-Wide Groundwater Monitoring Report, 2013

As of June 2022, the Multistate Trust has:

  • Recovered ±6,000 gallons of creosote from beneath the ground

  • Treated and discharged ±78,000,000 gallons of contaminated groundwater

  • Installed more than 20 groundwater monitoring wells

  • Collected more than 900 soil, groundwater, surface water, indoor air, and outdoor air samples

 

City of Springfield Sewer Main Pipe

In the residential area adjacent to the Facility, the City of Springfield’s (the City) sewer main pipe was found to be degraded and damaged from exposure to chemicals consistent with Facility operations. In 2020, the Multistate Trust began working with the City and the MoDNR to address the sewer main pipe issues and minimize the potential of contaminant migration. The City and Multistate Trust addressed the most critical pipe repairs in 2020 and 2021, including repair of ±9,500 linear feet of sewer main pipe. The Multistate Trust continues to work with the City to identify areas where additional sewer line repairs may be warranted.

 

Current Activities and Work

Due to the Facility’s proximity to residential neighborhoods, the Multistate Trust is prioritizing evaluating both off-Facility contaminant migration and potential exposures of the community to chemicals.

The Multistate Trust has continued implementing the MoDNR-approved Off-Facility Investigation Work Plan, which includes:

  • surface water sampling at Woodlawn Spring, Golden Hills Detention Basin, and the West Fork of Spring Branch;

  • sampling selected public water wells;

  • installing additional groundwater monitoring wells.

Click image to enlarge.

In 2024, the Multistate Trust is planning to:

  • Prepare a work plan and collect soil samples from certain residential properties on High Street;

  • Update the Facility’s conceptual site model (CSM) to evaluate the effectiveness of the groundwater treatment system;

  • Develop plans for removing potentially contaminated soil from the Golden Hills Detention Basin, constructing an engineered wetland in the basin to remediate contaminated groundwater from Woodlawn Springs, and increase basin aesthetics.

As in previous years, the Multistate Trust continues to comply with the MHWMF Part I Permit by performing PCC and corrective actions.

 

Regulatory Framework

The Springfield Facility is regulated as a closed hazardous waste land disposal facility under the State’s Resource Conservation and Recovery Act (RCRA) hazardous waste program. In 1987 and 1988, Kerr-McGee entered into a RCRA Consent Order and Corrective Action Order with EPA, respectively. In 2002, the Facility’s EPA orders were replaced with the MHWMF Part I Permit, along with an EPA-issued Hazardous and Solid Waste Amendments (HSWA) Part II Permit. In 2020, PCC and corrective actions were consolidated under the MHWMF Part I Permit. The State of Missouri is authorized to implement the RCRA hazardous waste program for all permitting, PCC, and corrective actions at the Facility.

 

Our Beneficiaries and Regulatory Agencies

In Springfield, the Multistate Trust is working with state and federal governmental beneficiaries for the Facility:

  • The state of Missouri, represented by the Missouri Department of Natural Resources (MoDNR); and

  • The United States, represented by the U.S. Environmental Protection Agency (EPA).

The MoDNR is the lead agency, which approves site-specific budgets, cleanup plans, activities, and contractors at the Facility. As beneficiaries, the MoDNR and EPA must approve any sale or transfer of the property.