Author(s)

G. E. Hoag, W. Guite, M. Lanoue, B. McAvoy

Abstract

An in situ treatment that combined VeruTEK Technology’s patented surfactantenhanced in situ chemical oxidation (S-SICO^®) technology with Wavefront Technology Solutions US Inc’s Primawave technology, a novel pressure-pulsing injection enhancement process, and a patent-pending process to quantify subsurface contamination and measure the effectiveness of full-scale treatment, successfully remediated coal tar-related contamination at a former lumber processing facility in New York City. This remedy overcame standard obstacles to effective in situ remediation: even distribution of the injected chemistry and effective transport at the pore-scale level; solubilization of NAPL contaminant into the aqueous phase where it can be oxidized; and identification of the amount and location of the contaminant mass for targeted treatment. Contamination at this site, the future location of a public library on the shore of a New York City river, included residual NAPL within the pore spaces of the soil matrix. Remediation was required reduce the mass of BTEX, naphthalene and PAHs in soil and reduce groundwater concentrations. The remedial process began with a laboratory treatability study that demonstrated the effectiveness of S-ISCO using VeruSOL and alkaline-activated sodium persulfate to destroy the recalcitrant coal tar contamination from site soils. Next, the three technologies (S-ISCO, Primawave and advanced investigation) were implemented during a one-month pilot test. The full-scale remediation that followed, under approval by the NYSDEC, included 5 months of injections accompanied by comprehensive groundwater monitoring at wells within and outside of the treatment area. Monitoring also included collection of soil samples halfway through the injection process to inform modifications to the final stage of injections. The success of the full-scale remediation will be presented, as well as an evaluation of the advantages to combining S-ISCO, Primawave and advanced site investigation to increase the effectiveness of in situ treatment of MGPs.

Keywords

coal tar remediation, in situ oxidation, surfactant enhanced oxidation