1. April 24, 2013S. Shawn Turner, PGDean Carter, PE, CGCBrendan V. BrownAPWA Florida 2013 Annual Meeting & Trade ShowGroundwater Remediation ProcessCase Study - Bioremediation of a ChlorinatedSolvents Site

2. Presentation Agenda2 Why Remediation is relevant at a Public Works Conference? Brief Description of the Groundwater Remediation Process Factors to consider for project success Overview of remediation technologies and selection criteria Case Study: Bioremediation of an Industrial Manufacturing Facility Conceptual Site Model / Remedial Alternatives Analysis Pilot Study Implementation of Selected Remedy System OptimizationAgenda 3. Why is Site Remediation Relevant? Contamination can be identified at any time Maintenance Shops / USTs Landfills / Solid Waste facilities Transportation Projects Land Redevelopment Projects Site Remediation is rarely planned for Rules/Regulations/Options are often not well understood3General Site Remediation Process 4. General Site Remediation Process4General Site Remediation Process 5. Generalized Site Remediation Process5 Site Assessment Conceptual Site Model Development Remediation Technology Screening Remedy Specific Sample Collection Bench-Scale / Pilot Testing (Proof of Remedy) Final Remedy Selection / Remediation Design Remediation Construction / Implementation Operation, Maintenance, and Monitoring Optimization Post-active Remediation Monitoring Site ClosureDesignPilot StudyRemediationAlternativesAnalysisConstruction /ImplementationOperation,Maintenance, &MonitoringOptimizationSite ClosureSite AssessmentGeneral Site Remediation Process 6. Technologies & SelectionCriteria6 Ex-situ Treatment Air-Sparge / SVE Bioremediation In-situ Chemical Oxidation In-situ Chemical Reduction Barrier Technologies Thermal Solidification/StabilizationSource: Federal Remediation Technology Roundtable RemediationTechnology Screening Matrix and Reference Guide, Version 4.0General Site Remediation Process 7. Chlorinated Solvent Groundwater RemediationTechnology UsageSource: The Lebron Study, 2004Thermal 27 (22.9%)Bioremediation 25 (21.2%)Chemical Oxidation 25 (21.2%)Dual Phase 13 (11.0%)Excavation 11 (9.3%)Other 4 (3.4%)ZVI/Nano-scaleIron 7 (5.9%)SurfactantFlushing 6 (5.1%)General Site Remediation Process 8. Project Success Depends on Multiple Factors8Chemicals ofConcernSite GeologyLand UseCostScheduleRules /RegulatorySite RestrictionsOM&M /ReliabilitySuccessfulRemediationGeneral Site Remediation Process 9. Former Industrial Manufacturing Facilityin Orlando, Florida Primary Contaminants:(typically 100,000 - 700,000 ug/L) 1,1-DCE methylene chloride 3 Surficial Aquifer Zones: shallow (water table) intermediate (semi-confined) deep (confined) Contamination under existing facilitySelected Remedy: BioremediationEnhanced with Groundwater CirculationCase Study: Bioremediation of a ChlorinatedSolvents SiteSite Description9 10. Contaminants of Concern Chlorinated Solvents High Concentrations (up to700,000 ug/L) Site Geology 3 contaminated aquifer zones Clayey sands and clays Site Considerations Existing Manufacturing Building Existing Hydraulic Control System Land Use Planned for mixed useredevelopmentSite Factors considered during the RemediationAlternatives AnalysisSite Description10 Schedule No specific redevelopmenttimeframe Low priority Cost Always a high priority Regulatory Initiated through consent order Client wants unconditional NFA Technology/Reliability innovative technologiesconsidered 11. Pilot Study11Pilot Study 12. Confirmed presence ofDehalococcoides spp.e- donor: potassium lactateGroundwater recirculation usedto distribute lactatenorthEAB Pilot Test was conducted in the highestconcentration area of the siteVOCse- donormicrobesPilot Study12 13. 4 Extraction Wells 1 Injection Well Circulate 4 - 5 days/week Excess water ex-situ air-stripperBioremediation Pilot Study was conducted todemonstrate Proof of ConceptPilot Study13 14. Illustration depicting biostimulation enhancedwith groundwater circulationDehalococcoides Electron DonorPilot Study14 15. Baseline Month 4Baseline Month 4VCresults1,1-DCE Results: Concentrations reduced by up to4 orders of magnitude in 4 monthsDCEresultsPilot Study15 16. Ethene concentrations increased throughoutthe pilot test cellBaseline Month 4Pilot Study16Ethene results 17. Implementation of Selected Remedy17Implementation of Selected Remedy 18. Baseline TVOC results showed multiple wellsabove 100,000 g/L18Implementation of Selected Remedy 19. Full-scale EAB: Horizontal extraction and verticalinjection wells used to distribute lactate193 Horizontal WellSegments50 Injection WellsIntermediate (30)Deep (20)Implementation of Selected Remedy 20. The horizontal wells cut through all three surficialaquifer zonesImplementation of Selected Remedy20 21. One-Pass Trencher and Installation of theHorizontal WellsImplementation of Selected Remedy21 22. One-Pass Trencher and Installation of theHorizontal WellsImplementation of Selected Remedy22 23. 510152025303540Feet(bls)- Potassium Lactate- Dehalococcoides spp.- Monitor Wells- Water ExtractionGraphical depiction of groundwater circulationand pulsed lactate injectionImplementation of Selected Remedy 24. Implementation of Selected RemedyHW-1HW-224Molar concentrations of chlorinated solventsduring EAB system cycling 25. TVOC Results Intermediate25Startup Month 6CurrentYear 2Implementation of Selected Remedy 26. pH Optimization26Optimization 27. Areas of slower degradation generally had low pH27pHTVOCOptimization 28. Approach to pH Buffering28pH OptimizationpH buffer selection/calculation Bicarbonate pH modeling indicated need for ~6,000 lbs of bicarbonate Calculated solution ratios based on aquifer volume and field scaletestingChemical delivery/monitoring Limited access inside the building/future use of building Direct injection of horizontal well water to provide microbes Gravity feed of bicarbonate and lactate solutions Sub-slab vapor and indoor air monitoring 29. Injection wells were installed to address lowpH/high TVOC concentrations under the building29pH Optimization 30. pH under the building was lower than optimallevels for reductive dechlorination30Baseline pH LevelspH Optimization 31. Multiple injections of bicarbonate, lactate andextracted groundwater were completed31HCO3LactateHWs(Direct pumping)pH Optimization 32. Bicarbonate and lactate injections wereconducted by gravity feed32pH Optimization 33. Bicarbonate Injections and pH Results33010002000300040005000600070003.54.55.56.57.58.59.512/18/08 03/28/09 07/06/09 10/14/09 01/22/10 05/02/10 08/10/10 11/18/10 02/26/11 06/06/11CumumaltiveBicarbonateInjected(lbs)pH(SU)DatepH Under Building & Bicarbonate InjectedINJ29-4IINJ29-5IINJ29-6IINJ29-7IMW-29IBicarbonatePurging atMW-29I startedpH Optimization 34. MW-29I Purging34pH Optimization 35. Bicarbonate Buffer System Equilibrium Reactions35CO2(aq) + H2O H2CO3 H+ + HCO3- 2H+ + CO32-pH Optimization 36. Molar Concentrations: MW-29I36048121620010020030040050060012/18/08 03/28/09 07/06/09 10/14/09 01/22/10 05/02/10 08/10/10 11/18/10 02/26/11 06/06/11mol/L(Ethene)mol/L(DCE/VC)DateChlorinatedEthenes1,1-DCEVinyl ChlorideEthene048121620010020030040050060012/18/08 03/28/09 07/06/09 10/14/09 01/22/10 05/02/10 08/10/10 11/18/10 02/26/11 06/06/11mol/L(DCA/Ethane)mol/L(TCA)DateChlorinatedEthanes1,1,1-TCA1,1-DCAEthaneSummary 37. pH Optimization Results376,000 lbsbicarbonateSummary 38. Full-Scale EAB Results38TVOC mass = 2,800 lbs TVOC mass = 6 lbsSummary 39. Questions and Answers39 40. Alternate Technology Cost ComparisonFrom McCabe et al. (2005)EnhancedEnhancedBioremedBioremed..n = 11n = 11ChemicalChemicalOxidationOxidationn = 13n = 13CosolventCosolventSurfactantSurfactantn = 6n = 6ThermalThermaln = 6n = 6110100100010000Enhanced Chemical Cosolvent ThermalBioremediation Oxidation Surfactantn=11 n=13 n=6 n=6CostperVolume($/cuyd)110100100010000Enhanced Chemical Cosolvent ThermalBioremediation Oxidation Surfactantn=11 n=13 n=6 n=6CostperVolume($/cuyd)MaxMax75th %75th %MedianMedian25th %25th %MinMinKEYKEY$2/yd$2/yd33$27/yd$27/yd33$29/yd$29/yd33$225/yd$225/yd33$152/yd$152/yd33$20/yd$20/yd33$47/yd$47/yd33$125/yd$125/yd33$194/yd$194/yd33$518/yd$518/yd33$66/yd$66/yd33$118/yd$118/yd33$385/yd$385/yd33$1322/yd$1322/yd33$5500/yd$5500/yd33$32/yd$32/yd33$48/yd$48/yd33$88/yd$88/yd33$129/yd$129/yd33$300/yd$300/yd33EnhancedEnhancedBioremedBioremed..n = 11n = 11ChemicalChemicalOxidationOxidationn = 13n = 13CosolventCosolventSurfactantSurfactantn = 6n = 6ThermalThermaln = 6n = 6110100100010000Enhanced Chemical Cosolvent ThermalBioremediation Oxidation Surfactantn=11 n=13 n=6 n=6CostperVolume($/cuyd)110100100010000Enhanced Chemical Cosolvent ThermalBioremediation Oxidation Surfactantn=11 n=13 n=6 n=6CostperVolume($/cuyd)EnhancedEnhancedBioremedBioremed..n = 11n = 11ChemicalChemicalOxidationOxidationn = 13n = 13CosolventCosolventSurfactantSurfactantn = 6n = 6ThermalThermaln = 6n = 6EnhancedEnhancedBioremedBioremed..n = 11n = 11ChemicalChemicalOxidationOxidationn = 13n = 13CosolventCosolventSurfactantSurfactantn = 6n = 6ThermalThermaln = 6n = 6110100100010000Enhanced Chemical Cosolvent ThermalBioremediation Oxidation Surfactantn=11 n=13 n=6 n=6CostperVolume($/cuyd)110100100010000CostperVolume($/cuyd)MaxMax75th %75th %MedianMedian25th %25th %MinMinKEYKEYMaxMax75th %75th %MedianMedian25th %25th %MinMinKEYKEY$2/yd3$27/yd3$29/yd3$225/yd3$152/yd3$20/yd3$47/yd3$125/yd3$518/yd3$194/yd3$66/yd3$118/yd3$385/yd3$5500/yd3$1322/yd3$32/yd3$48/yd3$88/yd3$300/yd3$129/yd3RITS Fall 2007: BioState of the PracticeEnhancedBioremediationn=11ChemicalOxidationn=13CosolventSurfactantn=6Thermaln=6General Site Remediation Process