Application of CSIA in Assessing and Cleaning Organics-Contaminated Sites Dr. Yi Wang Director, ZymaX Forensics Isotope April 5, Brownfields 2011

U.S. EPA Recognized Advanced Site Diagnostic Tool CSIA A Guide for Assessing Biodegradation and Source Identification of Organic Ground Water Contaminants using Compound Specific Isotope Analysis (CSIA) U.S. EPA 2008 A Guide for Assessing Biodegradation and Source Identification of Organic Ground Water Contaminants using Compound Specific Isotope Analysis (CSIA) U.S. EPA 2008 “In appropriate circumstances, CSIA can be used to provide new line of evidence, identify the mechanisms, and estimate the rate of degradation” - John T. Wilson, U.S. EPA 2010 “In appropriate circumstances, CSIA can be used to provide new line of evidence, identify the mechanisms, and estimate the rate of degradation” - John T. Wilson, U.S. EPA 2010 To download, go to for EPA 600/R-08/148

Welcome to the CLU-IN Internet Seminar Stable Isotope Analyses to Understand the Degradation of Organic Contaminants in Ground Water Sponsored by: U.S. EPA Technology Innovation and Field Services Division Delivered in 2010: 6/16, 9/9, 9/16, 10/27, 2:00 PM - 4:00 PM, EDT Instructor: John T. Wilson EPA, R.S. Kerr Environmental Research Center Visit the Clean Up Information Network online at

Stable Isotope Ratio  Ratio of the two most abundant stable isotopes of an element in a sample (  ‰). For carbon,  13 C = [( 13 C/ 12 C sample )/( 13 C/ 12 C standard )-1]x1000  Isotope ratio of manufactured chemical product depends on Feedstock and Process that a manufacturer used at a specific time period Clark & Fritz, 1997

Stable Isotope Ratio is Stable Unless Certain Process Alters It % Contaminant Remaining % Contaminant Remaining Degradation-Breaking Bonds (non-conservative) Non-Degradation (conservative) Evaporation (non-conservative)

CSIA Identified 3 PCE Releases “Mission Impossible” by Concentration U.S. EPA Guide, 2008

Assume Starting Ratio 13 C/ 12 C =1/9 After Degradation Ending Ratio=1/3 John Wilson 2010 Cl Cl Cl C l C 12 C 12 Cl Cl Cl C l C 12 C 13 Thomas McHugh et al C-Cl bond is slightly weaker than 13 C-Cl bond Example: PCE Getting Enriched in 13 C During Bond-Broken Degradation

3D-CSIA Determines TCE Origin 1  13 C (‰, PDB)  2 H (‰, SMOW) Manufactured TCE & c-DCE TCE & c-DCE from Degrading PCE Wang and Smith, 2010

Case 1: CSIA Found Same Origin for PCE Along Gradient Carbon CSIAConcentration Source Identification by CSIA Forensics cDCE (‰) TCE (‰) PCE (‰) cDCE (µg/L) TCE (µg/L) PCE (µg/L) Up Gradient MW Down Gradient MW Original  13 C Ratio of PCE in Well MW-1 [(-33.4)*8+(-34.2)*14+(-30.5)*4900]/( ) = -30.5‰ Original  13 C Ratio of PCE in Well MW-2 [(-34.3)*6+(-28.9)*7+(-29.9)*12]/(6+7+12) = -30.7‰

PRP A:  13 C = -30‰  37 Cl = -2‰ PRP B:  13 C = -25‰  37 Cl = +3‰ Plume = 80% PRP A + 20% PRP B Sueker, 2003 Case 2: Cost Allocation Between Two PRPs by 2D-CSIA Calculated by 13 C: (-29)*1 = (-30)*A + (-25)*(1-A) A=80% Confirmed by 37 Cl: (-1)*1 = (-2)*A + 3*(1-A) A=80% Co-mingled Plume:  13 C = -29‰  37 Cl = -1‰

Concentrations (µg/L) Case 3: PCE/TCE Plumes Defined by 3D-CSIA Wang and Smith, 2010

PCE/TCE Plumes 1D-CSIA:  13 C of PCE Wang and Smith, 2010 Two PCE Releases?  2‰ Required as Precision is ±0.5‰

PCE/TCE Plumes 2D-CSIA:  37 Cl of PCE Wang and Smith, 2010 Two PCE Releases Confirmed

PCE/TCE Plumes 1D-CSIA:  13 C of TCE Wang and Smith, 2010 TCE plume affecting the adjacent wells? TCE plume Known Degradation Product TCE

PCE/TCE Plumes 3D-CSIA:  2 H of TCE  Onsite TCE release, limited migration Wang and Smith, 2010 TCE plume Degradation Product TCE

3D-CSIA Defined PCE/TCE Plumes Wang and Smith, 2010

Pirkle, 2006; Burns, 2010 Case 4: CSIA Tracked ISCO PCETCE Sampling Event Pre- ISCO Post- ISCO 1 Post- ISCO 2 Pre- ISCO Post- ISCO 1 Post- ISCO 2 CSIA (  13 C,‰) Conc. (µg/L) CSIA Tracked Effective ISCO and Rebounds Light  13 C ISCO: Heavy  13 C Rebound Light  13 C Light  13 C ISCO: Heavy  13 C Rebound Light  13 C

 13 C vs.  37 Cl of TCE extracted during in situ remedial activities (Vapor Extraction, Steam Injection, and Electrical Resistance Heating) Case 5: 2D-CSIA Tells Mechanism Heavier BiodegradationSolubilizationEvaporation Wang and Smith, 2010

Location Depends on Purpose Samples Preliminary Survey to Justify Comprehensive Study 4 to 6 Wells Comprehensive Survey or Monitoring Natural Attenuation 12 to 24 wells Up gradient of source Up gradient of source 1 to 2 wells 1 to 2 wells Source zone Source zone 3 to 5 wells 3 to 5 wells Center flow line Center flow line 4 to 5 wells 4 to 5 wells Boundary of plume Boundary of plume 4 to 8 wells 4 to 8 wells Vertical extent in same well Vertical extent in same well 1 to 4 wells 1 to 4 wells Plume Stability: Quarterly - Yearly 6 to 15 wells U.S. EPA Guide, 2008; John T. Wilson, 2010 CSIA Sampling Strategy

Thank you! Questions and Comments? Contact: Dr. Yi Wang Director, ZymaX Forensics Isotope 600 South Andreasen Drive, Suite B Escondido, CA Phone: ext 43