Managing C&D Debris for the Future

Architecture 2030 has stated that a third of existing US buildings will be demolished by 2050—waste that, in large part, goes straight to landfills. In Minnesota, a staggering 90 percent of construction and demolition (C&D) debris is generated by demolition activity related to commercial and residential redevelopment.

The Minnesota Pollution Control Agency (MPCA) hired MSW Consultants through a competitive procurement process to determine where C&D materials come from and where they are brought to for disposal, to work towards changing current practices for C&D disposal and diversion. Our team conducted a statewide study, sampling the composition of the state’s C&D waste and estimating the percentages of major material groups and categories present using our proprietary app that incorporates material densities with volumes observed in the load. We then looked at current recycling and diversion opportunities and identified options for future opportunities.

Separation Prior to Disposal is Key

During the study, our team characterized nearly 1,700 tons of C&D waste, classifying 375 loads into 42 subcategories that rolled up into eight primary material groups. We found the three largest categories—concrete, roofing shingles, and dirt/sand/rock/gravel—represent 54 percent of C&D waste when combined and have a high potential for reuse or recycling if separated at the job site prior to collection.

Report Wrap-up

Recommendations resulting from the study included:

• Routinely update MN statewide C&D composition research to track change.

• Increase facility participation in future studies to gather data that may vary by region or other parameters.
• Conduct statewide C&D facility “at the gate” surveys to get a more thorough data set on the generators of C&D and any other materials entering the facility
• Create a robust and thorough contractor, hauler, and retailer survey to gather insight into which markets are strongest and weakest and confirm what support is needed to increase C&D recovery.
• Implement statewide reuse or recycling requirements, such as:
  • Create deconstruction and demolition certifications.
  • Provide incentives for material reuse and recycling.
  • Secure adequate sorting and storage spaces on job sites.
  • Investigate the potential for local requirements, such as deconstruction ordinances.

Making a Change

The MPCA supports and encourages programs that will result in C&D debris being re-used or recycled rather than buried in landfills. Visit https://www.pca.state.mn.us/waste/sustainable-building-and-materials to learn more about quarterly Built Environment meetings, All for Reuse Map & Matrix website, Building Material/Waste Management Plan template, the monthly newsletter, and more. (MN residency is not required to subscribe or learn from Minnesota!)

Calling All States

The magnitude of C&D debris in the overall waste streams across the country is astonishing. States (or counties or cities…) could see great environmental planning benefit by conducting C&D characterization studies and implementing more sustainable building material management practices or requirements.

Cynthia Mormile
Sr. Project Manager
MSW Consultants
cmormile@mswconsultants.com
Phone: 573-818-2281

Melissa Wenzel
Built Environment Sustainability Administrator
Minnesota Pollution Control Agency
melissa.wenzel@state.mn.us
Phone: 651-757-2251