title: Secondary environmental impacts of remedial alternatives for sediment contaminated with hydrophobic organic contaminants.
abstract: This study evaluates secondary environmental impacts of various remedial alternatives for sediment contaminated with hydrophobic organic contaminants using life cycle assessment (LCA). Three alternatives including two conventional methods, dredge-and-fill and capping, and an innovative sediment treatment technique, in-situ activated carbon (AC) amendment, are compared for secondary environmental impacts by a case study for a site at Hunters Point Shipyard, San Francisco, CA. The LCA results show that capping generates substantially smaller impacts than dredge-and-fill and in-situ amendment using coal-based virgin AC. The secondary impacts from in-situ AC amendment can be reduced effectively by using recycled or wood-based virgin AC as production of these materials causes much smaller impacts than coal-based virgin AC. The secondary environmental impacts are highly sensitive to the dredged amount and the distance to a disposal site for dredging, the capping thickness and the distance to the cap materials for capping, and the AC dose for in-situ AC amendment. Based on the analysis, this study identifies strategies to minimize secondary impacts caused by different remediation activities: optimize the dredged amount, the capping thickness, or the AC dose by extensive site assessments, obtain source materials from local sites, and use recycled or bio-based AC.
authors.affiliation: Department of Civil and Environmental Engineering, Seoul National University, Seoul 151-744, South Korea. Electronic address: ychoi81@snu.ac.kr.
authors.forename: Yongju
authors.initials: Y
authors.lastname: Choi
authors.affiliation: Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, USA.
authors.forename: Jay M
authors.initials: JM
authors.lastname: Thompson
authors.affiliation: Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, USA.
authors.forename: Diana
authors.initials: D
authors.lastname: Lin
authors.affiliation: Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, USA.
authors.forename: Yeo-Myoung
authors.initials: YM
authors.lastname: Cho
authors.affiliation: Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, USA.
authors.forename: Niveen S
authors.initials: NS
authors.lastname: Ismail
authors.affiliation: Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, USA.
authors.forename: Ching-Hong
authors.initials: CH
authors.lastname: Hsieh
authors.affiliation: Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, USA.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Luthy
keywords: Hunters Point; Life cycle assessment; Secondary environmental impact; Sediment remediation