View Spring 2021 issue

Spring 2021

Helping preserve the beauty of northern Minnesota, Barr provided ARD mitigation oversight services on highway realignment project.

Addressing the risks of acid-generating materials

March 15, 2021

Blasting and excavation on projects may expose sulfide-bearing rocks and soil to oxygen, which can create acidic runoff (acid rock drainage or ARD) and leach metals. This can disrupt the area’s pH balance and negatively impact plants and animals. On larger-scale mining projects, ARD can pose lasting consequences to the watershed and incur long-term water treatment costs.

Ultimate guide to ARD

"any project site – a railroad, a highway, a pipeline corridor, or a mine – involving rock disturbance may be at risk for acid runoff."

Barr provides site evaluation and mitigation implementation services for ARD on many projects, including on a recent highway realignment in northern Minnesota. Due to this project, the Minnesota Department of Transportation (MnDOT) hired Barr to develop a guidance manual with the University of Minnesota’s Natural Resources Research Institute (NRRI). The manual describes how to screen, characterize, evaluate, and mitigate acid-generating material, provides an environmental monitoring outline, and includes a geologic map to identify Minnesota areas at higher risk for acid-generating materials.

“Our team of geochemists, geologists, engineers, and environmental scientists created this valuable tool that MnDOT and other clients can leverage during their project planning phase,” says Kevin Eisen, Barr’s project lead for the manual. Because any project site – a railroad, a highway, a pipeline corridor, or a mine – involving rock disturbance may be at risk for acid runoff, planning is crucial. To learn more about the manual or mitigating ARD on your project, contact us.

About the authors

Kevin Eisen is a senior geological engineer with more than 22 years of experience assisting clients with emerging contaminants, legacy contamination, and ARD evaluation and mitigation. He managed the overall development of the MnDOT PAG guidance manual and has experience in state- and federally led ARD-related projects.

Denise Levitan is a senior environmental scientist and geochemist who has evaluated ARD potential for mining, power, and public-sector clients. She has a decade of experience with environmental analysis and assessment, solving problems related to all phases of industrial-project lifecycles.