The Minnesota Department of Transportation (MnDOT) recently released Transportation Research Synthesis (TRS) 2601, “Biochar Design Guidance,” a February 2026 report that explores how biochar can be effectively integrated into transportation projects. As the Principal Investigator of this research project, SRF Project Director Erin Hunker and her team assisted MnDOT in moving towards their goal of improving environmental performance and soil health in their transportation projects.
The report responds to a growing need for practical design guidance as MnDOT and other agencies invest in sustainable stormwater management, bioretention systems, and pollutant load reduction strategies. By synthesizing existing research and real‑world practices, the research and report lay the foundation for a future statewide biochar design manual that can be used immediately on active projects.
Research Insights on Biochar Use in Transportation Projects
TRS 2601 compiles insights from state interviews, national surveys, and follow‑up discussions with departments of transportation, environmental agencies, and private‑sector experts that already use biochar in infrastructure applications. The research highlights how different commercially produced biochar materials are being applied for temporary sediment control and permanent soil and water quality improvements, particularly in roadway and drainage environments. The synthesis documents existing specifications, design standards, and lessons learned, giving practitioners a clear snapshot of current best practices across the transportation industry.
Why Biochar Design Guidance Matters for Sustainable Engineering
As transportation agencies look to reduce environmental impacts while maintaining performance and durability, biochar offers a low‑cost, multifunctional solution that supports soil stabilization, stormwater treatment, and long‑term sustainability goals. MnDOT’s Biochar Design Guidance does not set final requirements, but instead provides a research‑backed reference to guide continued evaluation, pilot projects, and eventual formal standards. For engineers, planners, and sustainability professionals, TRS 2601 represents a significant step toward scalable, environmentally responsible transportation design rooted in real‑world practice and shared knowledge across agencies.
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Key Findings from MnDOT TRS 2601
- MnDOT identified a near‑term need for biochar design guidance to support current transportation projects.
- Biochar improves stormwater management, soil health, and pollutant reduction in roadway environments.
- Agencies are applying biochar in temporary sediment control and permanent infrastructure solutions.
- Nationwide adoption is increasing among DOTs, environmental agencies, and private partners.
- Inconsistent specifications across agencies highlight the need for standardized guidance.
- The report synthesizes existing research and practice but does not establish formal requirements.
- Findings will help shape future MnDOT engineering and sustainability standards.
Erin Hunker, PE, CFM
763.452.4837
Erin is a Project Director in our Water Resources group. She has more than 20 years of experience in water resources planning, engineering, and design, and hydrologic and hydraulic modeling. She also has expertise in comprehensive stormwater planning for municipalities, and has completed design reviews for municipalities and institutions.
In addition to more traditional storm sewer and stormwater pond designs, Erin has designed innovative green stormwater infrastructure Best Management Practices (BMPs) that enhance the project environment while meeting regulatory requirements.