How WGM Helped Clean Up the MRL Triangle: A Landmark Environmental Project in Missoula

The left graphic shows an aerial view of the MRL Triangle site. The right graphic shows an aerial view of the MRL Triangle site with lead concentrations in MRL Park.

Delisting the MRL Triangle Superfund Site: A Major Step for Missoula’s Redevelopment Efforts

After six years of hard work, WGM Group, the Montana Department of Environmental Quality (DEQ), and the City of Missoula Brownfields Program are in the final steps of delisting the state Superfund site commonly known as the MRL Triangle. This marks a key milestone for the project, which will allow the City of Missoula to redevelop the northern portion of the site and maintain the southern portion of the site as a city park. The public comment period for delisting opened on February 4, 2025, and ends on March 6, 2025.

The History and Environmental Cleanup of the MRL Triangle Site

The Montana Rail Link (MRL) Triangle, located at 1930 South Avenue West in Missoula, was listed as a state Superfund site in 1994 due to contamination from industrial and railroad activities. In 2017, the City acquired the MRL Triangle and quickly set out to clean it up using EPA Brownfields funding, aiming to “delist” it from the Superfund list and return it to productive use. At that time, the northern portion of the project site was used by various commercial businesses and the southern portion was mostly vacant for over a decade. Historically, land in the southern portion of the site was contaminated with lead while the northern portion of the site generally contained minor concentrations of arsenic, barium, and polycyclic aromatic hydrocarbons (PAHs).

WGM Group’s Role in the Cleanup Process

WGM’s innovative approach to leverage US EPA Brownfields funding for the assessment and cleanup of this site sets the project apart as something that – to our knowledge – has not be done before. Through the DEQ’s Voluntary Cleanup and Redevelopment Act (VCRA) process, we were able to expedite the project and reduce costs when compared to traditional methods.

In June 2024, the final cleanup phase was completed, which included removing arsenic-contaminated soil from the site. Covenants that were agreed to as part of the cleanup guarantee that future use remains “recreational,” providing green space for residents to enjoy.

What’s Next for Missoula’s MRL Triangle Redevelopment

This project represents a major win for the City of Missoula and the environment. Through innovation, collaboration, and hard work, WGM helped transform a contaminated site into a safe, usable space for future generations. We’re proud to have played a part in this long-awaited project and look forward to seeing the positive impact it will have on the community for years to come.

Contaminants and Cleanup Process: What Was Involved

  • Grant Writing & Technical Memorandums

  • Analysis of Brownfields Cleanup Alternatives (ABCA) development

  • Programmatic Quality Assurance Project Plan (PQAPP) development

  • Sampling and Analysis Plans (SAPs)

  • Conceptual Site Model (CSM) development

  • Monitoring Well Installations and Groundwater Monitoring

  • Soil and Groundwater Sampling for Contaminants of Potential Concern (COPCs)

  • Voluntary Cleanup Plan – Environmental Assessment (VCP-EA) development

  • Voluntary Cleanup Plan – Remediation Proposal (VCP-RP) development

  • Site Surveys

  • Community Relations Plan (CRP)

  • State Historic Preservation Office (SHPO) Compliance

  • Public Forums with Public Outreach

  • Individual Meetings and an Information Repository

  • Development and Submittal of the Construction Completion Report (CCR)

Ashley Scully