Eric Bergeron, Eng., M.Sc., Golder Associates, Golder Associates, 9200, boul Acadie, Montreal, Quebec, Canada H4N 2T2, Tel: 514-383-0990, Fax: 514-383-5332
Mathieu Barbeau, Eng., M.Sc., Golder Associés Innovations Appliquées (GAIA) Inc., 9200, boul Acadie, Montreal, Quebec, Canada H4N 2T2, Tel: 514-389-1631, Fax: 514-383-5332
Kateri Normandeau, Eng., Golder Associés Innovations Appliquées (GAIA) Inc., 9200, boul Acadie, Montreal, Quebec, Canada H4N 2T2, Tel: 514-389-1631, Fax: 514-383-5332
Adriana Peisajovich, Eng,.Ph.D, Environmental Affairs, Transport Canada, Regional Office Government of Canada, Dorval, Quebec Canada H4Y 1G7, Tel: 514-633-3956, Fax: 514-633-3250
Ginette Lajoie, Cree Regional Authority, Environment Coordinator, 277 Duke, Suite 100, Montréal, Quebec, Canada H3C 2M2, Tel: 514-861-5837, Fax: 514-861-0760

The Nitchequon project involves the dismantling of petroleum tanks and the chemical treatment of diesel impacted soil to eliminate the risks for wildlife, fauna and flora, and allow the Cree community to develop the land as an outfitting operation. 

The complexity of the project resides greatly in the logistical aspects, due to site location, accessible only by helicopter or hydroplane, with no access route, landing field, electricity or services, and where the short summer period reduces the treatment period

The remediation technique selected consists in a soil chemical oxidation treatment with potassium permanganate combining in situ and ex situ treatment. The process developed is innovative because permanganate is not usually used for hydrocarbon treatment. 

The ex situ step of the soil mixing in the reactors allows a 50% reduction of hydrocarbons.  This first phase of treatment required the design of efficient mixers, a perfect oxidant dosage and more importantly the optimization of the reactive agents’ addition sequence.  The in situ process allows increasing of the percentage of hydrocarbon reduction of about 10 to 30%.  The oxidant used has a kinetics that allows the retention of a residual concentration of permanganate in soils that oxidizes the most refractory hydrocarbons in the long run. 

Sustainable development was a priority throughout the entire project, in order to maximise the economic, social and environmental repercussions.  The site remediation, the minimal use of fuel, the recycling of dismantled metal, the fixing of various installations on site, the maximal implication of Cree labour (direct source of revenue and development of their competence) and finally the possibility of an economic activity in the region constitute a heritage for future generations.  The Canadian government has invested over 5 M$ for the realization of this project.  The management of the project was done in collaboration with TC and CRA.  

Evaluation of In Situ Chemical Oxidation of Soils at a Mixed Waste Site and Assessment of Effects on Ground Water Quality 

Richard C. Bost, Environmental Resources Management, 15810 Park Ten Place, Houston, Texas 77084, Tel: 281-600-1218, Fax: 281-600-1001, Email: rick.bost@erm.com
Robert G. Perry, Environmental Resources Management, 15810 Park Ten Place, Houston, Texas 77084, Tel: 281-600-1021, Fax: 281-600-1001, Email: robert.perry@erm.com

In Situ Chemical Oxidation (ISCO) entails the application or introduction of chemical oxidant into the subsurface for the oxidation and thereby the destruction/mineralization of organic constituents of concern (COCs) as a remedial technology.  The purpose of this paper is to present a case study that involved research and both bench-scale testing and field demonstration of ISCO for a mixture of chemicals, many of which have been identified as recalcitrant.  The paper also presents an assessment of ISCO’s effects on the underlying aquifer.  This paper illustrates an improved strategy that entailed the use of ISCO with mechanical mixing of clayey and silty soils to a depth of 25 feet in an affected area overlying a deeper aquifer.  This paper provides evidence of the successful application of ISCO at a site that resulted in over 95% removal of the principal COCs. Based on the apparent effectiveness of persulfate as demonstrated in bench-scale tests, ISCO utilizing persulfate and a source of alkalinity was then applied to an affected area at the site. The site is a 1970s era waste disposal area where a multitude of different types of wastes were disposed.  Six chemical constituents comprised the most abundant COCs at the subject site.  These compounds are: 1,1-dichloroethane, vinyl chloride, acetone, 1,2-dichloroethane, benzene, and tertiary butyl alcohol.  It was found that sodium persulfate can oxidize these compounds; however, the optimal reaction conditions vary for the different compounds.  Solutions of 20% sodium persulfate and 2% of different alkaline sources were found to be most effective in bench scale tests.  After the successful field demonstration, it was noted about a year later that dissolved oxygen and in situ natural attenuation degradation rates appear to have increased. The ground water data as well as the confirmatory field test and bench-scale test data are presented in the paper.

The Application of Sodium Persulfate to Achieve Drinking Water Standards

James R. Fair, PE, M.S. in Environmental Engineering from Clarkson University, Potsdam, NY.  Currently working with Weston & Sampson Engineers, Inc., 5 Centennial Drive, Peabody, MA, 01960, Tel: 978-532-1900 ext. 2334, Fax: 978-977-0100, Email: fairj@wseinc.com
George D. Naslas PG, LSP, Weston & Sampson Engineers, Inc., 5 Centennial Drive, Peabody, MA 01960, Tel: 978-532-1900 ext. 2279, Fax: 978-977-0100, Email: naslasg@wseinc.com

The rapid remediation of petroleum-contaminated groundwater using sodium persulfate at a site located in a potential drinking water source area in Weymouth , Massachusetts will be presented.  The groundwater at the site was contaminated with diesel and gasoline originating from leaking underground storage tanks (USTs).  When initial attempts to remediate the groundwater to meet the stringent drinking water standards using accelerated natural attenuation failed, an activated sodium persulfate compound was used because of its oxidation potential and its ability to be safely applied.  The results of groundwater monitoring illustrating the rapid oxidation of petroleum constituents, along with other key oxidation parameters, will be presented.  Because of the effectiveness of sodium persulfate, site closure was achieved quickly, resulting in significant savings.  The pitfalls and byproducts of sodium persulfate will also be reviewed.  In addition, the successful use of sodium persulfate to remediate volatile organic compound (VOC) contaminated groundwater will be discussed.

In-situ Chemical Oxidation of Residual Chlorinated Solvents - A Case History

Philip J. Knotts, URS Corporation, 5 Industrial Way, Salem, NH 03079, Tel: 603-893-0616 ext. 2233, Email: Philip_knotts@urscorp.com

At a manufacturing facility in New England, tetrachloroethylene, a dense non-aqueous phase liquid (DNAPL), leaked from an underground tank system.  The solvent percolated down through saturated silty sand, encountered an underlying saturated low-permeable clay, and migrated down-slope on the surface of the clay until adsorbed and immobilized by the soil.  As ground water flows through and around the impacted soil, the residual DNAPL gradually dissolves into and is transported with the ground water, resulting in a quasi-steady-state dissolved-phase plume that extends downgradient from the source area. 

In-situ chemical oxidation was selected as the initial step of the remedial action plan, with significant reduction of the residual mass of DNAPL in the soil as the primary goal, which will ultimately reduce the time required to achieve ground water quality standards at the site.  In-situ chemical oxidation bench and pilot-scale tests were performed, and a ten percent solution of RegenOxTM was injected into the soil at the site, as recommended by the vendor (Regenesis). 

Prior to the initial injection event, an injection and soil sampling grid was established, and pre-injection soil samples were obtained and analyzed to provide a baseline for performance evaluation.  The ground water quality baseline was established from the results of several years of monitoring conducted at the site.  Injections were performed in November 2005 and May and August 2006.  Post-injection soil and ground water samples were obtained and analyzed following each injection event. 

This presentation includes descriptions and photos of the procedures and equipment used to mix and inject the oxidizing solution, observation of the chemical reactions and problems encountered, and an evaluation of the impacts of the injections on soil and ground water quality at the site to date.  

A Pilot Study Using The iSOC^® System To Remediate Diesel Range Petroleum Hydrocarbons 

Daniel Servetas, P.E., Shaw Environmental, Inc., 13 British American Boulevard, Latham, NY 12110-1405, Tel: 518-783-1996, ext. 236, Fax: 518-783-8397
Cecelia Campbell, Shaw Environmental, Inc., 2790 Mosside Boulevard, Monroeville, PA 15146-2792, Tel: 412-858-3977, Fax: 412-372-8968
Heather Fariello, Shaw Environmental, Inc., 13 British American Boulevard, Latham, NY 12110-1405, Tel: 518-783-1996, ext. 279, Fax: 518-783-8397
Paul J. Kurzanski, CSX Transportation, Inc., 500 Water St. J-275, Jacksonville, FL 32202, Tel: 904-359-3101, Fax: 904-245-2826

A pilot test was designed and conducted to evaluate the effectiveness of the in-situ Submerged Oxygen Curtain (iSOC^®) technology on the treatment of diesel range petroleum hydrocarbons and fuel oil at a site located in northern New York State.  The pilot study was based upon results of previous investigations and eight years of routine groundwater monitoring conducted at the site.  iSOC^® is an oxygen delivery technology that infuses high levels of oxygen into the groundwater (without sparging), thus promoting natural attenuation.  Results from previous investigations at the site indicated that there was residual hydrocarbon impacts (both dissolved and non-aqueous phase) in an area of the site where historical releases occurred.  A Corrective Action Plan was developed and implemented to address the residual light non-aqueous phase liquid (LNAPL) contamination.  Upon completion of the LNAPL removal from the site, a round of groundwater and soil sampling delineated the extent of residual dissolved and non-aqueous phase hydrocarbons located within the saturated zone of the site.  Down gradient groundwater and soil investigations and monitoring show that the extent of the hydrocarbons in the groundwater and soil has remained limited to the confines of the site.  Due to the shallow depth to groundwater (approximately 3 feet), the limited extent of residual hydrocarbons, tight soils, poor groundwater recharge, extreme weather conditions and the presence of structures on site which further reduce direct access to the subsurface, iSOC^® technology was identified as a potential means to further remediate the site.  Data gathered during the pilot study indicates that both volatile organic carbon (VOC) and semi-volatile organic carbon (SVOC) concentrations have been significantly decreased in two of the three monitoring wells located within the pilot test area.  An evaluation of this pilot test will be presented, including the results of performance monitoring.  

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