Geosyntec professionals will make a significant technical contribution to the Seventh International Symposium and Exhibition on the Redevelopment of Manufactured Gas Plant Sites at the Sheraton New Orleans Hotel in Louisiana on October 16-18, 2017.
Geosyntec will be represented by 10 attendees and will be delivering five presentations. Savron, a division of Geosyntec, will also deliver a poster presentation. Presentation topics include innovative remedial technologies, novel analytical techniques, and a unique MGP redevelopment case study.
The symposium is an ongoing educational and networking event that focuses on specific issues related to the remediation and redevelopment of former manufactured gas plant sites.
Monday – October 16, 2017
3:20 pm – 4:50 pm
Session 2 – In-Situ Technologies
Progress Report for Application of STAR at a Former Manufacturing Facility
Len de Vlaming (Geosyntec), John Vidumsky (DuPont Corporate Remediation), Gavin Grant, Grant Scholes and David Major (Savron), Michaye McMaster (Geosyntec)
Savron's in situ smoldering technology using Self-sustaining Treatment for Active Remediation (STAR) is being applied as the primary source remedy at a former coal tar processing site located in Newark, New Jersey. Geosyntec is the at-risk project manager for the site owner, with Savron as the technology provider. The STAR technology relies on the contaminant itself to be the fuel source and with supplied air, ignition is initiated. Once ignited, the burn is propagated with the supplied air only and not more heat. The process can even be sustained below the water table. This process has been deployed at a former coal tar processing site in Newark. Site contaminants include coal tars and cresols in both fill and native geological materials. The remedial objectives include treatment of free product to the extent practicable. STAR was selected as a cost-effective and non-invasive alternative to available remediation alternatives including ISCO, in-situ stabilization, and conventional dig-and-haul. Two complete process trains, including air delivery, heaters, vapor extraction/treatment, and controls, are actively remediating the site and will continue to operate until anticipated completion in mid-2018. Approximately 2000 sequentially-grouped ignition points are anticipated, covering 14 acres at depths ranging from 10 to 35 feet bgs. To date, the project has successfully demonstrated in-situ treatment of heavy hydrocarbon free product as observed in soil cores, analytical testing, and other indirect evaluation means for a range of soil types, groundwater depths, and contamination profiles. This presentation will discuss key findings and progress of and evolutionary improvements to the technology since the remediation program was initiated.
Large Diameter Augers – Exploring Remediation Opportunities Beyond In Situ
Solidification/Stabilization (ISS) and Excavation
Jim Langenbach and Jim Linton (Geosyntec)
The application of large diameter augers (LDA) for ISS and excavation is a routinely applied remedial approach for addressing MGP sites. Looking beyond ISS and/or excavation, additional innovative technology applications exist for LDA, including: (i) LDA with steam injection and zero valent iron polishing (LDA/Steam/ZVI), (ii) LDA mixing with in situ chemical oxidation (ISCO) injection (LDA/ISCO), and (iii) LDA for the construction of engineered phytoremediation TreeWell™ systems (LDA/Phyto). This presentation will provide an overview of traditional LDA technology applications and then present a summary of non-conventional LDA applications that, depending on the site-specific conceptual site model, may have applicability to MGP sites. LDA/Steam/ZVI technology applications will focus on the implementation and results of the technology applied to treat volatile plumes and potential applications and/or permutations at MGP sites. The LDA/ISCO technology application will explore the fundamentals of ISCO, surfactant enhancements, and the typical challenges associated with the technology that can be overcome via the use of an LDA mixing system to distribute/mix oxidants at MGP sites. Lastly, the application of the LDA/Phyto technology application will be presented to demonstrate how the LDA system is used in the application of an engineered TreeWell™ system to achieve and/or enhance hydraulic containment and enhance reduction of contaminants of concern over time. While the application of LDA for ISS and excavation will likely remain a mainstay for many MGP sites, innovative permutations of the LDA technology offer alternative approaches to addressing site-specific challenges that warrant consideration.
Tuesday – October 17, 2017
4:10 pm – 5:00 pm
Session 8 – "Lightning Round" for Various Topics
Field-Scale Trial of Sodium Persulfate for Treatment of MGP Residuals
Andrew P. Brey, P.G. (Geosyntec), Neil R. Thomson (University of Waterloo)
Remediation of sites contaminated with non-aqueous phase liquids (NAPLs) such as manufactured gas plant (MGP) residuals or "coal tars" are problematic and hence a variety of technologies have been developed that enhance the rate of mass removal, which is vital to attaining site restoration. Chemical oxidation has been touted as a potential silver bullet to deal with MGP residuals and NAPLs; however, the science base is lacking in peer-reviewed scientific or engineering literature to support its use in full-scale applications. Geosyntec, in conjunction with University of Waterloo researchers, is currently performing a field-scale trial at a former MGP in Clearwater, Florida to evaluate the use of sodium persulfate to treat a mass of residual NAPL. The focus of the project research is to perform a multi-year pilot-scale evaluation of the ability of a chemical oxidant (sodium persulfate) to treat the source and remaining dissolved-phase groundwater plume. The site source and plume are located in a well-sorted, unconfined sandy aquifer. Multi-level sampling grids were installed within and downgradient of the source area and have been monitored at regular intervals since 2011 to establish baseline groundwater conditions. Additionally, laboratory treatability evaluations (oxidant demand/interaction, aqueous, and slurry) have been completed by the University of Waterloo. During 2015, the field experimental trial was performed utilizing two injection events of base-catalyzed persulfate within the target treatment zone (TTZ). Dissolved phase concentrations, contaminant mass in the TTZ, and mass discharge across the downgradient multi-level sampling grid have been monitored and evaluated to assess treatment performance. The presentation will discuss the conceptual site model, treatment system design, and system monitoring and performance results to date (2017).
Wednesday – October 18, 2017
10:30 am – 12:00 pm
Session 10 – Remediation Case Studies Part II
Flexibility and Optimization: A MPE Success Story at Tampa MGP
Rachel Klinger, P.E., Jim Langenbach, P.E. and Andrew Brey, P.G. (Geosyntec), Chris Gasinski (TECO Peoples Gas)
TECO Peoples Gas System (TECO) operated a manufactured gas plant (MGP) in Tampa, Florida, dating to approximately 1905. Based upon site-specific complexities, including existing buildings, roadways, trolley line, and a hydrogeologic setting which includes a significant groundwater gradient, Geosyntec identified Multi-Phase Extraction (MPE) as a viable remedy for remediation of the mobile Non-Aqueous Phase Liquid (NAPL) source area. Due to these unique complexities, the fast-track nature of the project, and uncertainties associated with extracting NAPL from the subsurface, the MPE system design included a significant amount of flexibility to facilitate real-time optimization during operations. In under one year, Geosyntec designed, permitted, constructed, and operated an aggressive, innovative, and highly flexible MPE system to recover and treat mobile NAPL, groundwater, and vapor-phase contaminants. This presentation will provide an overview of how proven remediation technologies were mixed with new techniques to maximize NAPL recovery and maintain a high level of operational flexibility and optimization. Since startup in July 2016, the MPE system has recovered over 8,100 gallons of NAPL as of March 2017, and when combined with dissolved and vapor-phase mass treated, represents over 33 tons of MGP-related impacts from the subsurface.
Smoldering Combustion (STAR and STARx) for the Treatment of Contaminated Soils: Challenges Encountered & Lessons Learned in Providing a New Remediation Technology to the Industry
Presenter: Gavin Grant, Ph.D. (Savron)
Authors: Gavin Grant, Ph.D., David Major, Ph.D., and Grant Scholes (Savron)
STAR (in situ) and STARx (ex situ) are innovative remediation technologies based on smoldering combustion where the contaminants themselves are the source of fuel. The first part of the presentation will focus on in situ applications of STAR and present a series of case studies. The first case study involved the STAR treatment of two contaminated horizons (DNAPL and LNAPL) in a fine sand unit at a former Manufactured Gas Plant (MGP) site in northern Michigan. Self-sustaining smoldering combustion was achieved in both zones resulting in a Radius of Influence (ROI) of approximately eight feet with an average propagation rate of approximately one foot per day. The second case study involved the first in-situ field application of a surrogate fuel (emulsified vegetable oil [EVO]) to support combustion of high volatility compounds including gasoline and diesel fuel at a former refinery in Michigan. Successful injection and combustion of EVO resulted in an increased ROI as compared to the "standard" STAR test. The third case study involved the STAR treatment of Navy Special Fuel Oil (NSFO) within a former tank farm area in Virginia. The field test successfully treated contaminated soil located both above and below a discontinuous clay layer. The second part of the presentation will focus on ex situ applications of STARx and present a case study involving a full-scale HottpadTM system designed to treat hydrocarbon-impacted soils at a site in southeast Asia. HottpadTM systems are fully scalable, modular platforms containing the ignition infrastructure required to smolder soil piles placed on top. The case study will present data showing the simplicity, excellent treatment efficiency, and flexibility of the system to meet project-specific needs. Lessons learned from field applications of STAR will be presented, focusing on common issues encountered at MGP sites and methods recently developed for maximizing treatment efficiency.
For more information regarding the event, visit: http://mgpsymposium.com/