Evaluation of geosynthetics used in barrier systems to contain hydrocarbon-contaminated soils in Antarctica
Daniel Jones, Rebecca McWatters, Greg Hince, Daniel Wilkins, Tim Spedding, Malek Bouazza, Will Gates, R. Kerry Rowe, Ian Snape
In the proceedings of: GeoMontréal 2013: 66th Canadian Geotechnical Conference; 11th joint with IAH-CNCSession: Geosynthetics - Landfills and Mining Operations
ABSTRACT: Two fuel spills at AustraliaÕs Casey Station (66¡17' S 110¡31' E) in Antarctica, in 1999 and 2010, resulted in contaminant migration down-gradient towards permafrost soil. Elevated hydrocarbon levels were detected in soil surrounding both sources. On-site remediation techniques were chosen to clean the soil within its natural environment and meet obligations to the Protocol on Environmental Protection to the Antarctic Treaty. An active treatment method was specifically tailored to the site and risks associated with Antarctic operations and environment. Soil was excavated in 2011 through 2013 and placed in biopile treatment cells with nutrient addition and aeration systems. The six biopiles were designed with a geosynthetic composite liner system using geosynthetic clay liners (GCLs), high density polyethylene (HDPE) geomembranes and geotextiles. Different combinations of GCL types and geomembrane thicknesses are used in the biopiles and compared to investigate the ideal barrier design for Antarctic environments. A seventh biopile was created in 2013, using a co-extruded HDPE and ethylvinyl alcohol (EVOH) geomembrane. This is the first time geosynthetics have been used in field applications in Antarctica and the first time that this co-extruded liner has been tried in a field application. Research is also focused on the long-term performance of these geosynthetics to impede contaminant migration with exposure to the AntarcticÕs cold and dry climatic conditions and freeze-thaw cycling. Sample extraction pipes were positioned in the barrier system to monitor for any outward contaminant migration. Results after the first season of biopile operation show no hydrocarbon migration below the GCL liner. Sacrificial geomembranes and GCLs coupons were placed within the barrier system and samples were exhumed after one and two years in the field. These underwent material performance testing in the laboratory. It is expected that the biopiles will operate for a number of years with monitoring and sampling regimes during summer months. R…SUM… Deux fuites de carburant ‹ la Station Casey d'Australie (66¡17'S 110¡31'E) en Antarctique, en 1999 et 2010, ont eu comme cons”quence lÕinfiltration de contaminant ‹ travers le perg”lisol. Des niveaux ”lev”s d'hydrocarbure ont ”t” d”tect”s dans le sol autour des deux sources. Des techniques sur place de rem”diation ont ”t” n”cessaires afin de nettoyer le sol dans son environnement naturel tout en respectant les obligations fix”es par le protocole environnemental du Trait” dÕAntarctique. Biopiles, qui a ”t” mise en application, est une m”thode de traitement active, avec les syst‘mes nutritifs d'addition et d'a”ration sp”cifiquement con“us en fonction du site, des risques li”s aux op”rations en antarctiques et de l'environnement. Le sol a ”t” excav” de 2011 ‹ 2013.Six cellules biopile de traitement ont ”t” con“ues avec un rev’tement g”osynth”tique compos” utilisant argile g”osynth”tique (GCLs), g”omembranes et g”otextiles de poly”thyl‘ne ‹ haute densit” (HDPE).Diff”rentes combinaisons de diff”rents types de GCLs et de diff”rentes ”paisseurs de g”omembranes sont utilis”es dans les biopiles. En les comparants, une barri‘re optimale pour lÕenvironnement arctique a pu ’tre cr””e. Un septi‘me biopile a ”t” cr”” en 2013, utilisant une g”omembrane co-expuls” de HDPE et d'alcool d'ethylvinyl (EVOH). C'est la premi‘re fois que les g”osynth”tique sont employ”s dans des applications de terrain en Antarctique. CÔest ”galement premi‘re fois que ce rev’tement co-expuls” est essay” dans une application de terrain. La recherche est ”galement concentr”e sur lÕ”volution ‹ long terme de ces g”osynth”tiques. Le but ”tant dÕemp’cher la migration de contaminant sous une exposition aux conditions climatiques froides et s‘ches de l'antarctique et au cycle gel-d”gel. La migration de contaminant a ”t” observ”e ‹ lÕaide dÕun syst‘me de tuyaux plac”s dans le complexe dÕ”tanch”it”. Les r”sultats apr‘s la premi‘re saison d'exposition des biopiles montrent quÕaucune migration d'hydrocarbure au-dessous du rev’tement de GCL nÕest ‹ d”plor”e. Des ”chantillons de g”omembranes et de GLCs ont ”t” pr”lev”s apr‘s un et deux ans dans le complexe dÕ”tanch”it”. Ils ont subi des tests de performances (r”sistance aux produits chimiques, perm”abilit”,..) en laboratoire On s'attend ‹ ce que les biopiles fonctionnent pendant un certain nombre de saisons sous la surveillance et avec la r”alisation dÕun ”chantillonnage accrus pendant la saison d'”t” chaude.
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Daniel Jones; Rebecca McWatters; Greg Hince; Daniel Wilkins; Tim Spedding; Malek Bouazza; Will Gates; R. Kerry Rowe; Ian Snape (2013) Evaluation of geosynthetics used in barrier systems to contain hydrocarbon-contaminated soils in Antarctica in GEO2013. Ottawa, Ontario: Canadian Geotechnical Society.
@article{GeoMon2013Paper457,author = Daniel Jones; Rebecca McWatters; Greg Hince; Daniel Wilkins; Tim Spedding; Malek Bouazza; Will Gates; R. Kerry Rowe; Ian Snape,title = Evaluation of geosynthetics used in barrier systems to contain hydrocarbon-contaminated soils in Antarctica,year = 2013}