Environmental Services (Brownfields Support): Cass Lake, MN

Tribal Land TBA, EPA Region 5 Brownfields Program, Cass Lake, MN
Environmental ServicesOTIE conducted a Phase I and Phase II TBA on a tribal land in Region 5 on behalf of USEPA. OTIE provided the technical assistance needed to further evaluate the current environmental conditions of a former gun range and illegal dump brownfield site near Cass Lake, MN. This Phase I and Phase II TBA was undertaken to assist the Leech Lake Band of Ojibwa with assessing the presence of contamination that may require corrective actions before returning the property to a natural state.

As part of Phase II TBA activities, OTIE prepared project plans and conducted sampling of previously identified recognized environmental conditions (RECs). These RECs were identified by the Tribe and confirmed by a Phase 1 Environmental Site Assessment TBA. The Phase II TBA consisted of surface and shallow soil sampling and grab groundwater sampling. In addition to these surface samples, an area with unidentifiable white powder was also sampled. Direct-push technology (DPT) borings were advanced into groundwater and soil samples were collected from each boring. Temporary monitoring wells were completed in each boring and groundwater samples were collected and submitted for laboratory analyses of volatile organic compounds, semi-volatile organic compounds, polynuclear aromatic hydrocarbons, RCRA metals, and PCBs.

To assess analytical data, OTIE compared sample results to proposed ESA screening levels, which were based on the Cleanup Levels (CLs) in the LLBO Hazardous Substances Control Act (HSCA). OTIE reviewed analytical results, made conclusions, and provided recommendations which included partial excavation and proper disposal of metal-contaminated soil and installation of monitoring wells and sampling of groundwater to evaluate metal contamination.

Client Name: USEPA Region 5


Location: Cass Lake, MN


Contract Value: $40K


Project Features:

  • Phase I TBA
  • Phase II TBA
  • Soil and groundwater sampling