Plant/Soil Zones to Prevent Movement of Copper and Zinc from Roads

Focus Area

Water Quality/Wetlands


Natural Resources






1-2 years

Research Idea Scope

I. Research Problem Statement
Due to automobile braking, roadside sediments in heavily trafficked regions have high levels of copper and zinc compared to sediment quality. Recent use of bio-retention filters has reduced runoff of heavy metals from parking lots in Maryland. A pilot study is warranted to look at the effectiveness of different kinds of soil-plant buffer zones in preventing movement of copper and zinc from roadsides.

II. Objective
To investigate optimal soil-plant systems to immobilize copper and zinc. Laboratory experiments should include determining the importance of soil buffering capacity, organic matter content and pH and other physical and chemical characteristics that immobilize the heavy metals. Experiments also need to be conducted to identify plants that impede uptake of copper and zinc into the above ground shoots. Fieldwork should include evaluation of experimental bio-retention devices at roadside intersections where braking is heavy and where immobilization of copper and zinc would be most useful.

Urgency and Payoff

The goal of the proposed project is to identify protective and relatively low cost technologies (planting and soil amendments) to reduce cost for future transportation projects and ameliorate existing problems in copper and zinc movement from roads. A significant immediate benefit would be protection of aquatic life from copper pollution, since fish and crustaceans are very sensitive to copper. Longer-term benefits would include public health benefits, improvement of carbon sequestration, due to plant canopies and below ground growth, and prevention of erosion and associated benefits.

Suggested By

TRB Research Needs Database, AFB40, Landscape and Environmental Design