Contaminated Materials

Contamination investigations

Phase I Environmental Site Assessment (ESA)

A Phase I ESA reviews the present and past operations and uses of a property to determine the potential presence of contaminated soil and/or groundwater. Phase I ESA findings are used to evaluate the potential risk of contaminated soil and/or groundwater impacting a project scope of work. If there is a risk of encountering contamination or acquiring a contaminated parcel a Phase II Investigation would be performed.

Phase II ESA

A Phase II ESA is a subsurface investigation which evaluates soil and groundwater conditions in areas of known or potential contamination, as identified in the Phase I ESA. The results of this investigation are used for the following:

• Obtain liability protection prior to acquiring contaminated property
• Determine the extent, magnitude and mitigation of chemical releases at facilities
• Develop contaminated material management plans for construction projects that address:
  • Disposal and/or reuse of contaminated soil
  • Dewatering in areas with contaminated groundwater

Construction Monitoring

Using data from the Phase II ESA contaminated material management plans, such as Response Action Plan and Special Provisions, are prepared when necessary. These plans are used during construction to guide management of contaminated soil and/or groundwater.

Special Provisions and Specifications

• MnDOT special provision 2106 identifies areas of known soil and groundwater contamination
  and project specific details on the management of those areas is written and coordinated by CMMT.
• MnDOT Specification 1717 describes contingency measures for unanticipated
  contamination. MnDOT Spec Book

Tools

• Checklist in lieu of 30% plans (PDF) - Phase II investigations utilize 30% design plans and proposed acquisition locations (EDD-2). If 30% plans are not available, MnDOT project managers should implement this checklist.
• Limited Phase I ESA Site Data Sheet template (Word) - MnDOT recommends that pre-qualified environmental consultants use this template as a guide when creating Site Data Sheets.
• Pre-qualified environmental consultants list - Used to conduct contracts for work type 5.4 contaminated property investigation. To learn more about this process please contact the Environmental Investigation Supervisor.
• Soil management flow charts:
  • Materials intermixed with debris (PDF)
  • Non-petroleum contaminated materials (PDF)
  • Petroleum contaminated materials (PDF)
• CMMT typical process (PDF)