Long Term Monitoring Data 2013
- 1. LONG TERM MONITORING DATA EVALUATION OF BIOAUGMENTATION DURING ISCR-ENHANCED BIOREMEDIATION OF TCE DNAPL James G.D. Peale, RG Erik I. Bakkom, PE (Maul Foster & Alongi Inc.) Jeff Roberts, Sandra Dworatzek (SiREM Laboratories) Josephine Molin (FMC Environmental Solutions) June 2013
- 2. Site Overview Technology Summary Problem Statement Analysis Results Summary Implications TOPICS
- 3. Former MGP waste site redeveloped for manufacturing in 1970s 80+ acres adjacent to Portland Harbor NPL site TCE released from a recycling system (1980-1985) Impacts from release discovered in 2002 TCE DNAPL Source Zone Impacts from about 5-34 m bgs TCE up to 592,000 ug/L (DNAPL levels) No TCE DNAPL observed Cis-1,2-DCE up to 90,800 ug/L Very little VC (< 100 ug/L) Site Overview
- 5. Technology Summary EHC Powdered blend of zero-valent iron (ZVI) and hydrophilic organic carbon Creates strongly reducing conditions in groundwater for in situ chemical reduction (ISCR) ISCR results in abiotic dechlorination and supports anaerobic bacteria KB-1 Anaerobic consortium of dechlorinating bacteria Includes dehalococcoides sp. Requires ORP < -75 mV Both technologies demonstrated success for dissolved CVOC plumes
- 6. Technology Summary EHC+KB-1 Full-Scale Implementation 46 m x 21 m x 3 m PRB – Source area only Injected from ~12 – 34 m bgs Supplemental upgradient areas 200+ injection points ~269,400 kg EHC 1,831 L KB-1 Direct-push drilling 23 Performance Monitoring Wells
- 10. Problem Statement Remedial action objective is 11,000 ug/L Threshold indicator for TCE DNAPL Achieved in less than 12 months Achieved mean TCE 3 ug/L Declining cDCE and VC, but still elevated in some wells Dhc counts 107 – 108 Question: how long can this continue? Will we see rebound?
- 11. Problem Statement How long will Dhc sp. flourish? Organic carbon needs (other) Continued reducing conditions? Field data Other functional requirements? Continued cVOCs?
- 12. Long-Term Data Sets Pilot Study Data 2006-2008 Shallow and deep wells, within and downgradient of injection zone Full-scale Data 2009-present 19 wells + pilot study wells Monitoring program includes: VOCs, TOC, Dhcv, vCRA Field parameters
- 13. CVOC Data – kg estimated in source area (EVS) 0 200 400 600 800 1,000 1,200 1,400 1,600 1,800 11/1/2008 5/20/2009 12/6/2009 6/24/2010 1/10/2011 7/29/2011 2/14/2012 9/1/2012 3/20/2013 TCE (kg) cDCE VC Ethene
- 14. CVOC Data – normalized (C/C0) to show ethene generation (also VC…uh oh) 0.001 0.01 0.1 1 10 100 Nov-08 May-09 Dec-09 Jun-10 Jan-11 Jul-11 Feb-12 Sep-12 Mar-13 TCE cDCE VC Ethene CVOC
- 15. Not to worry - VC Data regression y = -0.1601x + 6676.3 R² = 0.7136 -20 0 20 40 60 80 100 120 140 160 Dec-11 Apr-12 Jul-12 Oct-12 Jan-13 May-13 Aug-13 Nov-13 Mar-14 Jun-14 Estimated VC Mass (kg) Estimated VC Mass (kg) Linear (Estimated VC Mass (kg))
- 16. TOC Data – Mean of Full Scale Data Set (n=23) 194 0 500 1000 1500 2000 2500 3000 3500 Total Organic Carbon (Total and Dissolved) Primary Well Group (mg/L) TOC (Total) - Mean TOC (Total) - Geometric Mean TOC (Dissolved) - Mean TOC (Dissolved) - Geometric Mean Background TOC ~ 10 mg/L
- 17. Dhc Data – Full Scale Data Set (n=23) 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 7/1/2009 1/17/2010 8/5/2010 2/21/2011 9/9/2011 3/27/2012 10/13/2012 5/1/2013 DHC Full Scale Well Group (Count) 1/2 of non-detect values used
- 18. vCRA Data – full scale data set 1.00E+04 1.00E+05 1.00E+06 1.00E+07 1.00E+08 1.00E+09 1.00E+10 6/1/2008 12/18/2008 7/6/2009 1/22/2010 8/10/2010 2/26/2011 9/14/2011 4/1/2012 10/18/2012 5/6/2013 11/22/2013 vcrA Primary Well Group (Count) 1/2 of non-detect values used
- 19. TOC and DHC Data – Long Term (n=4) 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08 1.E+09 0 500 1000 1500 2000 2500 3000 3500 4000 5/1/2006 9/13/2007 1/25/2009 6/9/2010 10/22/2011 3/5/2013 Dhc(count) TOC(mg/L) WS-19 WS-18-101 WS-18-71 DHC
- 20. ORP data -200 -150 -100 -50 0 50 100 150 200 37922 38288 38653 39018 39383 39749 40114 40479 40844 41210 Redox potential Mean of Primary Well Group (n varies) eH - Mean
- 21. Analysis All indicators look good! VOC mass decreasing Sustained elevated TOC levels Sustained negative ORP levels Continued ethene generation Regression predicts VC decrease by 2014 Some indicators look iffy? Would like to see higher Dhc numbers? Others?
- 22. Results Success! Other considerations DNAPL/CVOC reduction Other Useful?
- 23. Summary (tbd) Literature range sets boundaries 20 – 750 yrs (latter less useful) Developing data set Regression provides simple tool for prediction Dual rates observed and should be considered Early consumption followed by equilibrium Modeling is promising approach Estimates match lower range of regression Can provide conservative (short) predictions to improve site planning/closure
- 24. Implications (tbd) Micro-scale ZVI is extremely durable Data fit well with other observations Similarity to presumed P&T timeframes (30 yrs) How do we manage long-term? Is monitoring required to demonstrate complete exhaustion? How can we extend confidence of this long-term remedy to support site closure?
- 25. Acknowledgements/Questions Thank you. SiREM Laboratories FMC Environmental Solutions Questions?