Demonstration Results for the Phytoextraction of Lead-Contaminated Soil at the Twin Cities Army Ammunition Plant, Arden Hills, Minnesota

This report describes the results of a two-year field demonstration conducted to determine if phytoextraction is a viable and feasible technology for remediation of metals (specifically lead) in soil. The project goal was to demonstrate the effectiveness of phytoextraction techniques for removing ionic lead from contaminated soils. The report also provides implementation guidance describing additional improvements needed prior to implementing this technology based on the field results. During the demonstration, soil acidifiers and a chelating agent were used to increase the water solubility of lead and the availability of lead to plants. The demonstration was conducted at the Twin Cities Army Ammunition Plant in Arden Hills, Minnesota. The report indicates that, overall, phytoextraction methods did not perform to expectations. An economic analysis indicates that the in situ phytoextraction as a sole use technology would not be economically viable at a highly contaminated site, even if performed under optimum conditions. Conditions that would improve performance would be uniform, agronomically viable soils that are not conducive to movement of lead out of the rooting zone, and in which soil lead is present in ionic forms. Sponsored in part by ESTCP.