Industrial Landfill

Wyandotte, Michigan

Roux Associates developed and implemented a phytoremediation alternative as a component of the closure of an industrial landfill located in Wyandott, Michigan. The native soil at the site posed a challenge for the designers as it was characterized by high pH (up to 12 units) and high salt content. The overall goal of the remediation was to minimize the volume of water moving through the inactive landfill cells and thus to significantly reduce leachate generation. The intent of the phytoremediation, therefore, was to minimize infiltration of precipitation into the two largest inactive landfill cells, as well as to intercept and evapotranspire groundwater migrating into the cells from upgradient portions of the site.

To achieve the objectives stated above, under the adverse growing conditions imposed by the poor soil quality, 3,450 specially-bred hybrid poplar tree cuttings were planted. The variety of hybrid poplar trees planted are salt tolerant, suitable for a northern climate and capable of transpiring between 10 and 50 gallons of water per day when mature. Based on the periodic monitoring of the trees growing at the site, 100-percent coverage of the target phytoremediation area was achieved and the remedial objectives are being met.