title: Investigation of chlorinated solvent pollution with resistivity and induced polarization.
abstract: Globally, an enormous number of polluted areas are in need of remediation to prevent adverse effects on health and environment. In situ remediation and especially the monitoring thereof needs further development to avoid costly and hazardous shipments associated with excavation. The monitoring of in situ remediation actions needs easier and cheaper nondestructive methods for evaluation and verification of remediation degree and degradation status of the contaminants. We investigate the Direct Current resistivity and time-domain Induced Polarization tomography (DCIP) method and its use within the context of a DNAPL (Dense Non-Aqueous Phase Liquids) contaminated site in Varberg, Sweden, where an in situ remediation pilot test has been performed by stimulated reductive dechlorination by push injection. Our results show that the DCIP technique is an emerging and promising technique for mapping of underground structures and possibly biogeochemical spatial and temporal changes. The methodology could in combination with drilling, sampling and other complementary methods give an almost continuous image of the underground structures and delineation of the pollutant situation. It can be expected to have a future in monitoring approaches measuring time lapse induced polarization (IP), if more research is performed on the parameters and processes affecting the IP-signals verifying the interpretations. The IP technique can possibly be used for verification of the effectiveness of in situ remediation actions, as the current sampling methodology is inadequate.
authors.affiliation: Department of Geology, Lund University, Sölvegatan 12, SE-223 62 Lund, Sweden. Electronic address: charlotte.sparrenbom@geol.lu.se.
authors.forename: Charlotte J
authors.initials: CJ
authors.lastname: Sparrenbom
authors.affiliation: Department of Geology, Lund University, Sölvegatan 12, SE-223 62 Lund, Sweden.
authors.forename: Sofia
authors.initials: S
authors.lastname: Åkesson
authors.affiliation: Tyréns AB, Idéon Science Park, Scheelevägen 17, SE-223 70 Lund, Sweden; Engineering Geology, Lund University, Box 118, SE-221 00 Lund, Sweden.
authors.forename: Sara
authors.initials: S
authors.lastname: Johansson
authors.affiliation: Department of Geology, Lund University, Sölvegatan 12, SE-223 62 Lund, Sweden; Tyréns AB, Idéon Science Park, Scheelevägen 17, SE-223 70 Lund, Sweden.
authors.forename: David
authors.initials: D
authors.lastname: Hagerberg
authors.affiliation: Engineering Geology, Lund University, Box 118, SE-221 00 Lund, Sweden.
authors.forename: Torleif
authors.initials: T
authors.lastname: Dahlin
keywords: DCIP; DNAPL; Geoelectrical measurements; Hydrogeological setting; In situ remediation; Sweden; Varberg