Leaching Behavior of Heavy Metals and Semi-Volatile Organic Chemicals from Waste Materials Wrapped and Unwrapped in Geotextile Fabric and Placed in Groundwater

Focus Area

Water Quality/Wetlands


Natural Resources







Research Idea Scope

Recent study findings where tire shreds were used for lightweight fill in road base construction in a wetland suggest that wrapping the tire shreds with a geotextile fabric could trap heavy metals and organic chemicals within the fabric wrap.  The observed trapping could be unique to the groundwater chemistry or geology of the current study site where installed.  The results of the current tire shreds study indicate that long term testing of groundwater is required to evaluate the long-term environmental effects of a waste material.This proposed study will construct field diffusion chambers at the Minnesota Department of Transportation MnRoad research facility.  The chambers will be in-soil trenches with tire rubber (belts removed), fly ash in flowable fill, and a tire rubber/flowable fill with fly ash mixture as treatment chambers and covered with excavated soils.  Control chambers without geotextile fabric but with the same waste material will be constructed for statistical testing of chemical concentrations.Once constructed with waste materials and flooded with well water, the chambers will equilibrate with leachate diffusing to the surrounding soils and water.  In-chamber water levels will be maintained for long-term leaching of the waste materials by natural precipitation and groundwater additions at the site.  During the third and fifth years of the study, chamber water will be withdrawn for ecotoxicity testing of three species of aquatic or terrestrial organisms for survival and reproductive chronic effects.

Urgency and Payoff

This study will also determine if the use of geotextile woven fabric is a viable option for trapping heavy metals and/or organic chemicals around the waste material in wetland construction sites or similar extreme wet environments.  Retaining chemicals close to the source material lessens the local environmental impacts

Suggested By

Robert Edstrom Minnesota DOT

[email protected]