Data Needs for Effective Application of MNA and In-Situ - PowerPoint PPT Presentation

Data Needs for Effective Application of MNA and In-Situ Bioremediation Featuring Framework to Apply Novel Molecular and Other Screening Tools for MNA Evaluations John Wilson, Principal Scientist, Scissortail Environmental Solutions, LLC, Ada, OK john@scissortailenv.com FRTR General Meeting USGS Headquarters, Reston, Virginia November 2, 2016 1

https://www.serdp-estcp.org/Program-Areas/Environmental-Restoration/Contaminated-Groundwater/Persistent-Contamination/ER-201129/ER-201129 2

You want the BioPIC Tool. Section 5 of the Final Report provides guidance of using a model to extract rate constants for biodegradation, and gives more detail than is provided in the decision criteria and help buttons of the BioPIC tool. 3

ESTCP P Proje oject E ER-201129 Dr. Frank Löffler Carmen A. Lebrón T. Wiedemeier Dr. John T. Wilson University of Independent Consultant Wiedemeier & Scissortail Environmental Tennessee Associates Solutions, LLC Mike Singletary Dr. Rob Hinchee Yi Yang NAVFAC SE Research Assistant UTK Integrated Science & Technology, Inc. 4

EPA/600/R-98/128 September 1998 5

Use of Monitored Natural Attenuation at Superfund, RCRA Corrective Action, and Underground Storage Tank Sites U.S. Environmental Protection Agency Office of Solid Waste and Emergency Response Directive 9200.4-17P 6

(1) Historical groundwater and/or soil chemistry data that demonstrate a clear and meaningful trend of decreasing contaminant mass and/or concentration over time at appropriate monitoring or sampling points. (In the case of a groundwater plume, decreasing concentrations should not be solely the result of plume migration. In the case of inorganic contaminants, the primary attenuating mechanism should also be understood.) 7

(2) Hydrogeologic and geochemical data that can be used to demonstrate indirectly the type(s) of natural attenuation processes active at the site, and the rate at which such processes will reduce contaminant concentrations to required levels. For example, characterization data may be used to quantify the rates of contaminant sorption, dilution, or volatilization, or to demonstrate and quantify the rates of biological degradation processes occurring at the site. 8

Unless EPA or the overseeing regulatory authority determines that historical data (Number 1 above) are of sufficient quality and duration to support a decision to use MNA, data characterizing the nature and rates of natural attenuation processes at the site (Number 2 above) should be provided. 9

Is the entire plume required to meet the goal? If so, at what date must concentrations in the plume meet the cleanup level? The performance depends on the success of source treatment, and the kinetics of natural attenuation of the source. These processes can not be evaluated or understood using Compound Specific Isotope Analysis (CSIA) or Molecular Biological Tools (MBT). 10

How far can the plume be allowed to extend? Will the rate of attenuation bring the highest concentrations in groundwater to acceptable concentrations before the groundwater reaches the receptor of the sentry well? Evaluated by extracting a rate constant from field data for the rate of degradation necessary to meet the goal. Compound Specific Isotope Analysis (CSIA) or Molecular Biological Tools (MBT) can provide a second line evidence to support a site conceptual model. 11

The decision logic in BioPIC Evaluate Biostimulation Start See Overview Biostim Bioaug Yes Evaluate Biostimulation And Are Reductive Does Natural Is the EPA 2nd No No Yes No Evaluate Bioaugmentation MNA without 2nd Line Dehalogenase Genes Attenuation Currently Line of Evidence See of Evidence Present? Meet the Goal? Required? Overview Biostim Bioaug (2) (1) (3) Yes PCE TCE DCE VC No No No Is VC Present? No Is TCE Present? No Line of Evidence Is DCE Present? No Line of Evidence No Line of Evidence No Line of Evidence Is PCE Present? (14) Required for TCE Required for DCE (4) Required for VC Required for PCE (9) (20) Yes Yes Yes Yes No No TCE Attenuation Caused by No No Is TCE Degrading? DCE Attenuation Caused by VC Attenuation Caused by PCE Attenuation Caused by Is DCE Degrading? Is VC Degrading? Is PCE Degrading? Dilution and Dispersion (15) Dilution and Dispersion Dilution and Dispersion Dilution and Dispersion (10) (5) (21) Yes Yes Yes Yes Evidence for at least some Evidence for at least some Yes reductive dechlorination reductive dechlorination Yes Yes Are Are TCE, DCE, DCE or VC Present? or VC Present? Does Dhc Density Quantitative Line of Does Dhc Density Quantitative Line of Yes (16) Yes (22) Are Are DCE or VC Explain the DCE Evidence for Anaerobic Explain the VC Evidence for Anaerobic TCE, DCE, or VC Present in Relevant Rate Constant? Microbial DCE Degradation Rate Constant? Microbial VC Degradation Present in Relevant Concentrations? (11) (6) Concentrations? (17) (23) No No No Yes No Yes Qualitative Line of Evidence Does Magnetic Does Magnetic Qualitative Line of Evidence Quantitative Line of Quantitative Line of Yes Yes for TCE Biodegradation. Susceptibility Explain the Susceptibility Explain the for PCE Biodegradation. Evidence for Abiotic DCE Evidence for Abiotic VC No Consider Determining pceA DCE Rate Constant? VC Rate Constant? No Consider Determining Degradation Degradation and tceA Gene Abundances pceA Gene Abundance (12) (7) No No Does Magnetic Does Magnetic Quantitative Line of Yes Quantitative Line of Yes Susceptibility Explain the Susceptibility Explain the Evidence for Abiotic TCE Adequate Evidence for Abiotic PCE Adequate Qualitative Line of TCE Rate Constant? Qualitative Line of PCE Rate Constant? Degradation Yes Oxygen for Aerobic Yes Degradation Oxygen for Aerobic VC Evidence for Aerobic DCE (18) Evidence for Aerobic VC (24) DCE Biodegradation? Biodegradation? Biodegradation Biodegradation (13) No (8) No No No PCE Degradation not Explained Does Iron Sulfide Quantitative Line of Yes DCE Degradation VC Degradation not Explain the TCE Rate Evidence for Abiotic TCE not Explained Explained Constant? Degradation (19) No TCE Degradation not Explained 12

Start Does Natural No Yes Attenuation Currently Meet the Goal? (1) 13

Use a computer model to project the previous behavior of the contamination forward in space and time. Will contaminants in the plume extend past the point of compliance at unacceptable concentrations? Yes. MNA not Adequate 14

Microbio iolo logy o of Red eductiv ive Dec echlo lori rinatio ion o of Ch Chloroethenes Can accumulate if requisite bacteria are not present Dehalobacter some strains of Dehalospirillum Dehalococcoides Desulfitobacterium Desulfuromonas Dehalococcoides 15

Evaluate Biostimulation Start See Overview Biostim Bioaug Yes Evaluate Biostimulation And Are Reductive Does Natural No No Evaluate Bioaugmentation Dehalogenase Genes Attenuation Currently See Present? Meet the Goal? Overview Biostim Bioaug (2) (1) Assays based on the Quantitative Polymerase Chain Reaction (qPCR) are used to identify the presence of organisms with genes that can degrade chlorinatred alkenes to harmless end products. If the density of the pceA, tceA, bvcA, or vcrA genes are greater than 1000 gene copies per liter of groundwater, that gene is considered to be present. 16

Start Does Natural No Yes Attenuation Currently Meet the Goal? (1) 17

Use a computer model to project the previous behavior of the contamination forward in space and time. Will contaminants in the plume extend past the point of compliance at unacceptable concentrations? 0.6 per year First Order Rate Constant PCE Prediction 1000 1.0 per year TCE Prediction 100 Concentration (mg/L) Regulatory Standards 0.7 per year DCE Prediction 10 2.0 per year VC Prediction 1 0.1 No. MNA is PCE Field Data Adequate 0.01 TCE Field Data 0.001 0 500 1000 1500 2000 2500 DCE Field Data Distance From Source (ft) VC Field Data Point of Compliance 18

Start Does Natural Is the EPA 2nd Yes No MNA without 2nd Line Attenuation Currently Line of Evidence of Evidence Meet the Goal? Required? (1) (3) Yes PCE TCE VC DCE 19

VC Degradation VC The primary line of evidence for degradation No Is VC Present? No Line of Evidence is the projection (4) Required for VC of the computer model. Yes The secondary line of evidence No VC Attenuation Caused by Is VC Degrading? is stable Dilution and Dispersion (5) isotopic fractionation as revealed by Yes CSIA. 20

The secondary line of evidence is stable isotopic fractionation as revealed by CSIA. 21