Lightly Contaminated Transportation Material Reuse Options and Specifications

Focus Area



Air Quality, Environmental Process






1-2 years

Research Idea Scope

Transportation agencies generate and then pay to dispose of large quantities of lightly contaminated materials such as street sweepings, gravel shoulder cuttings, and other roadway materials.  These lightly contaminated materials could be beneficially reused rather than landfilled.  Unfortunately due to regulations, stockpiling restrictions, inconsistent testing requirements, and long-term liabilities, there is a lack of reuse of these materials even though there is a high cost savings potential.  Due to unfavorable regulations, uncertainty in environmental impact, and unknown engineering properties, there are many detractors to the reuse of these materials.  Transportation agencies are generating increasing volumes of such materials, since new testing protocols detect contaminants in materials that had been previously thought of as clean.  For example, due to improved contaminant detection technology many agencies are required to increase the frequency of street sweeping to meet Municipal Separate Storm System (MS4) standards, which in turn generates more lightly contaminated material.  Once these materials have been deemed contaminated, the materials must be properly disposed of in regulated landfills which means more money is being spent on the disposal.  DOT’s from across the country are interested in solutions to this costly and mounting lightly contaminated material problem.

The primary objectives of this research are to:

  • Identify states that have favorable regulations related to the beneficial reuse of lightly contaminated transportation materials
  • Determine what makes favorable regulations function
  • Obtain and synthesize copies of favorable regulations and specifications
  • Obtain and synthesize testing protocols for lightly contaminated materials
  • Retrieve cost benefit information from projects that incorporated lightly contaminated materials
  • Identify possible end uses for lightly contaminated materials and associated risks
  • Create life cycle cost and risk analysis for each end use


Urgency and Payoff

Industrial by-product reuse in many states has shown that proper reuse of lightly contaminated materials is a benefit because: 1) using lightly contaminated materials reduces the need for virgin materials, and 2) using lightly contaminated materials reduces the need to use valuable landfill space.  Due to the many different regulations across the country, DOT’s have no agreed upon standards, testing methods, or guidelines in place for the reuse of lightly contaminated transportation materials.  Potential benefits enabled through the proposed research include:

  • Cost reduction associated with the use of less raw material
  • Cost reduction associated with less landfilling
  • Reduced hauling costs and carbon footprint
  • Resource conservations
  • Reducing use of virgin aggregate
  • Preserving landfill space
  • Greater predictability for construction and maintenance costs
  • Potential for public-private partnerships

Suggested By

Cyrus Parker, LG, PE, CPM GeoEnvironmental Supervisor North Carolina Department of Transportation 919 707 6868 office [email protected]

[email protected]