By Siddharth Vodnala, Voiland College of Engineering and Architecture

Washington State University researchers have received a grant to develop cost-effective ways to treat contaminated soils found during highway construction.

The goal is to find treatment methods for soils that are contaminated with a variety of toxic chemicals, such as petroleum hydrocarbons, arsenic or lead. Amanda Hohner, assistant professor in the Department of Civil and Environmental Engineering, is principal investigator on the three-year, $500,000 grant from the Illinois Center for Transportation.

During road construction projects, construction crews often discover contaminated soils, which are expensive to dispose of and environmentally hazardous. Currently, transportation agencies either move the contaminated soils to an off-site location for treatment, which is expensive, or dispose of them in landfills, which is unsustainable.

The WSU team hopes to treat such soils at the construction site itself and reuse the soil as construction fill.

“We will start off by identifying which contaminants are causing problems by sifting through ten years of available data,” said Hohner. This will help narrow down appropriate treatment options for those contaminants, she added.

The team will survey literature for on-site treatments to see which technologies can be applied to the wastes found during construction projects. They will then develop and test a variety of treatment plans and follow up with field testing at construction sites.

“We will test conventional methods like chemical oxidation treatment and bioremediation as well as emerging methods like electrochemical technologies,” said Hohner.

Soil type and contamination varies widely from one site to another, according to Hohner. The challenge will be to find treatment options that can be adapted to work on any construction site.

The team includes Richard Watts, a professor in the Department of Civil and Environmental Engineering and an expert on remediation, the process of removing pollution and contaminants from soil and water, as well as Xianming Shi, Idil Akin and Indranil Chowdhury, faculty members in the Department of Civil and Environmental Engineering. James Mueller, President of Provectus Environmental Products, Inc. which provides soil and groundwater remediation technologies, is also part of the research team.