Approaches to Integrating Source and Plume Treatment Strategies for - PowerPoint PPT Presentation

Approaches to Integrating Source and Plume Treatment Strategies for Long-Term Dilute Plume Management Kent S. Sorenson, Jr., PhD, PE June 20, 2012

Presentation Overview • Background • Potential degradation mechanisms • Strategies for technology integration

BACKGROUND

Test Area North • 1.5-mi TCE plume • 200 ft to water • 200-ft contaminated thickness • Sludge injection well at source • 1995 ROD – Pump and treat – 100-year cleanup

Fringe and Core Hypothesis (Cherry, 1996) • Generic chlorinated solvent plume conceptual model CORE FRINGE Mass Flux • 10 2 m, • 10 3 µ g/L • 10 3 m, • 10 2 µ g/L

POTENTIAL DEGRADATION MECHANISMS

Anaerobic Reductive Dechlorination PCE Cl Cl C I Chlorine Atom C C C Carbon Atom Cl Cl C I H Hydrogen Atom Single Chemical TCE Bond Double Chemical Cl Cl Bond C C Cl H 1,1 - DCE cis - 1,2 - DCE trans - 1,2 - DCE Cl Cl H H Cl Cl C C C C C C H H Cl H Cl H Vinyl Chloride H Cl C C H H Complete Mineralization Ethene H H O O O Cl C C C H H H H Ethane H H Modified from H H C C Wiedemeier et al., 1996 H H

Anaerobic Reductive Dechlorination TCE DCE + VC VC + Ethene

Anaerobic Reductive Dechlorination

Anaerobic Reductive Dechlorination DCE Stall Not Always Bad 80 DCE MCL 70 Concentration (ppb) 60 50 TCE (ppb) 40 DCE (ppb) 30 20 TCE MCL 10 0 0 2 4 6 8 10 12 Time (months)

Aerobic Cometabolism • Axial concentration ratios

Aerobic Cometabolism • Aerobic TCE degradation half-life: 12-15 years ( 3 H) • Aerobic DCE degradation half-life: 8-9 years ( 3 H) 3.5 0.0 TCE/PCE -0.5 y = -8.1E-04x + 3.2E+00 3.0 TCE/Tritium -1.0 R 2 = 9.2E-01 ln(TCE/tritium) 2.5 ln(TCE/PCE) -1.5 -2.0 2.0 -2.5 1.5 -3.0 -3.5 1.0 y = -1.3E-03x - 1.4E+00 -4.0 0.5 R 2 = 8.0E-01 -4.5 0.0 -5.0 0 500 1000 1500 2000 2500 3000 Distance, , from Well TSF-05 (m) x Sorenson et al., 2000; Wymore et al., 2007; Lee et al., 2008

Aerobic Degradation • 9 plumes evaluated at 4 DOE sites – Brookhaven National Laboratory – Paducah Gaseous Diffusion Plant – Savannah River Site – Rocky Flats • Aerobic TCE degradation rates evident at 8 out of 9 • Degradation half-life range: 0.85 – 12 years Koelsch et al., 2005

Biogeochemical Reduction by Iron Minerals • Twin Cities Army Ammunition Plant • TCE & DCE half-lives < 2.5 years Concentration of cis -DCE ( µ g/liter) Live Microcosms Autoclaved Controls 10000 Container Controls 1000 100 10 1 100 300 500 700 900 Time of Incubation (days) Ferrey et al., 2004

Biogeochemical Reduction by Iron Minerals • Resources EPA, 2009; ESTCP, 2008

STRATEGIES FOR TECHNOLOGY INTEGRATION

Prerequisites • Identification of intrinsic degradation mechanism • Estimate of intrinsic degradation rate (separate from dispersion) • Reasonable assurance of longevity of mechanism 0 0 -0.5 -0.5 Baetsle (1969) -1 -1.5 Analytical Model -1 /C ) y = -0.14t + 280 o -2 max R 2 = 0.99 ln(C -2.5 -1.5 -3 ln(TCE/TCE ) -3.5 o -2 -4 -4.5 -2.5 0 2 4 6 8 10 12 14 Time -3 -3.5 y = -0.020t + 38 -4 R 2 = 1.0 -4.5 -5 1990 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100 Year, t Sorenson et al., 2000

Fringe Types • Active Treatment Fringe (ATF) – Fringe Concentration > MNA capacity Bountiful • • Intrinsic Treatment Fringe (ITF) – Fringe Concentration ≤ MNA capacity TAN • • Well 12A

Active Treatment Fringe • Source removed/contained • Active treatment required in fringe to meet cleanup goals Mass Flux

Bountiful/Woods Cross Superfund Site Biobarrier Fringe Treatment Source Treatment

Bountiful (cont.) • Source treatment (anaerobic reductive dechlorination) started 2008

Bountiful (cont.) • Source flux stopped, downgradient biobarriers installed

Intrinsic Treatment Fringe • Source removed/contained • Intrinsic degradation in fringe sufficient to meet cleanup goals Mass Flux

Test Area North, OU 1-07B • 1997 TCE Distribution MNA Pump & Treat Bioremediation

Test Area North, OU 1-07B • 2009 TCE Distribution DOE, 2012

Test Area North, OU 1-07B • 2011 TCE Distribution DOE, 2012

Test Area North, OU 1-07B • MNA performance monitoring DOE, 2012

Test Area North, OU 1-07B • Zone 1 DOE, 2012

Test Area North, OU 1-07B • Zone 2 DOE, 2012

Test Area North, OU 1-07B • Zone 3 – Up to 30% temporary plume expansion allowed – Actual expansion 8.5% to 15% – Performance appears right on track! DOE, 2012

Well 12A Superfund Site • Tacoma water supply • Significant residual source material Core • Large, dilute plume • Estimated intrinsic degradation limit: 300 µ g/L Fringe

Well 12A Superfund Site • RAOs: – 90% mass discharge reduction from core Core – ARARs at designated points of compliance – Determine if MNA Fringe can meet ARARs in fringe

Well 12A Superfund Site • Detailed 3D source characterization for remedy design to stop mass discharge

Well 12A Superfund Site • Performance monitoring transects established for source treatment • MNA evaluation and performance monitoring underway

Acknowledgments • Kira Lynch (EPA) • John Wilson (EPA) • Sam Garcia (EPA) • Lee Nelson (Idaho National Laboratory) • Tamzen Macbeth (CDM Smith) • Nathan Smith (CDM Smith)

References • Baetsle, L.H. 1969. “Migration of Radionuclides in Porous Media.” In: A. M. F. Duhamel (Ed.), Progress in Nuclear Energy Series XII , Health Physics , pp. 707-730. Pergamon Press, Elmsford, NY. • Cherry, J. A. 1996. “Conceptual Models for Chlorinated Solvent Plumes and Their Relevance for Intrinsic Remediation.” In: Symposium on Natural Attenuation of Chlorinated Organics in Ground Water , pp. 29-30. Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC, EPA/540/R-96/509. • DOE. 2012. Annual Report for the Final Groundwater Remediation, Test Area North, Operable Unit 1-07B, Fiscal Year 2011 . DOE/ID-11464, Revision 0. 81 pp. EPA. 2009. Identification and Characterization Methods for Reactive Minerals Responsible • for Natural Attenuation of Chlorinated Organic Compounds in Ground Water. EPA 600/R-09/115. December. • ESTCP. 2008. Workshop on In Situ Biogeochemical Transformation of Chlorinated Solvents. February. • Ferrey, M. L., R. T. Wilkin, R. G. Ford, and J. T. Wilson. 2004. “Nonbiological Removal of cis- Dichloroethylene and 1,1-Dichloroethylene in Aquifer Sediment Containing Magnetite.” Environmental Science &Technology . 38(6):1746-1752.

References (cont.) • Koelsch, M., R. C. Starr, and K. S. Sorenson, Jr. 2005. “Assessing Aerobic Natural Attenuation of Trichloroethene at Four DOE Sites.” Proceedings of the Waste Management 2005 Conference, Tucson, AZ. • Lee, M. H., S. C. Clingenpeel, O. P. Leiser, R. A. Wymore, K. S. Sorenson, Jr., and M. E. Watwood. 2008. “Activity-Dependent Labeling of Oxygenase Enzymes in a Trichloroethene-Contaminated Groundwater Site.” Environmental Pollution . 153(1):238- 246. 2009. Sorenson, K. S., Jr., L. N. Peterson, R. E. Hinchee, and R. L. Ely. 2000. An Evaluation of • Aerobic Trichloroethene Attenuation Using First-Order Rate Estimation. Bioremediation Journal , 4(4):337-357. 2000. • Wymore, R. A., M. H. Lee, W. K. Keener, A. R. Miller, F. S. Colwell, M. E. Watwood, and K. S. Sorenson, Jr. 2007. “Field Evidence for Intrinsic Aerobic Chlorinated Ethene Cometabolism by Methanotrophs Expressing Soluble Methane Monooxygenase.” Bioremediation Journal . 11(3):125-139. 2007.