This report summarizes field observations, analytical results for soil cores and "crust" analyses on soil cores collected approximately 60 days after treatment. In addition, it presents the data associated with the Variance requirements associated with the use of the material.
Using subsurface soils from the Cabot Carbon / Koppers wood treating site in Gainesville, Florida, bench-scale engineering optimization tests previously demonstrated that such stabilization of creosote/penta NAPL residuals at the Site was technically feasible, and that this combination of reagents could potentially yield effective long-term NAPL stabilization and flux reduction of all monitored COI. Field-testing of the ISGS approach was subsequently undertaken to yield site-specific field data necessary to validate full-scale technology efficacy. Implementation of the ISGS field test was completed in the surficial aquifer at the former North Lagoon Area of the Site.
After only 60 days post-treatment, the ISGS technology was shown to provide safe, rapid, effective and predicted long-term treatment. There was no measurable free-phase NAPL in any of the monitoring wells; PAHs were reduced by 50% in soil; COIs present in soil leachate were reduced by 95%; and there was a qualitative reduction in permeability.