In Situ Bioremediation at FracRock Sites Mary F. deflaun, PhD

Transcription

1 In Situ Bioremediation at FracRock Sites Mary F. deflaun, PhD Slide 1

2 Overview Two case studies of bioaugmentation in fractured rock: 1. Naval Air Warfare Center in NJ fractured mudstones 2. Industrial facility near Nashville, TN karst Common Features: TCE at DNAPL concentrations treated using emulsified vegetable oil (EVO) as the electron donor and the anaerobic microbial consortia KB-1 (contains DHC bacteria) Co-author and instructor for the ITRC BioDNAPL Training Co-author for ITRC IDSS and Mass Flux guidance documents Guidance documents available at Slide 2

3 Naval Air Warfare Center, West Trenton, NJ Collaborators: Slide 3

4 Mercer County Airport Jet engine testing facility from 1950 s to 1990 s Est. 100,000 gals of TCE lost from storage tanks-10,000 gals est. to gw (~200 ppm max conc.) Areas of coincident jet fuel contamination Daughter products-cis-dce and VC present (16 & 1.2 ppm max) Triassic sedimentary rock fractured sand and mudstones 60 gpm pump & treat system since 1993 no decrease in TCE since 1998 Slide 4 GeoSyntec Consultants

5 Dipping Bedded Lockatong Mudstones Test area Black Fissile Mudstone Grey Laminated and Massive Mudstone Red Massive Mudstone 200 ft Slide 5 From Pierre Lacombe

6 Implementation Utilize 4 existing wells-areal extent 9,000 ft 2 up to 115 bgs 4 wells form a trapezoid 230 ft on the long side Estimate 220 lbs TCE in pilot area (up to 16 ppm) Inject EVO first to retain injected bacteria Slide 6

7 Pilot Test Injections Used the four wells as injection/extraction well pairs - extracted from one well of the pair while injecting into the other using flow proportional pump Pulled water from designated extraction well to make up 10% stock of EVO Injected the EVO stock with gw pulled from the extraction well to a final concentration of ~2%-until EVO visible in the extraction well Added 20 L KB-1 culture-dhc bacteria Injected the remainder of the EVO and flushed the well with at least 1 well volume of groundwater without amendments Slide 7

8 USGS Toxics Research Site core hole 68 BR drilled downgradient 41BR BR 3 38BR BRP1 5 47BR 100 ft 68BR GW Flow Direction Slide 8

9 Well 16BR CVOC Molar Concentrations: May 2005-March Injection Event May-05 8-Aug Aug Oct Dec-05 3-Apr-06 7-Jun Aug Nov Feb May-07 5-Mar-08 micromoles/liter cis-dce TCE VC ethene TCE= 288 ug/l Date Sampled Slide 9

10 Well 38BR CVOC Molar Concentrations: May 2005-March Injection Event 120 TCE = 15,800 ug/l 100 micromoles/liter cis-dce TCE VC ethene May-05 8-Aug Aug Oct Dec-05 3-Apr-06 7-Jun-06 Date Sampled 28-Aug Nov Feb May-07 5-Mar-08 Slide 10

11 Historical Concentrations at 38BR (μg/l) 1 0 0, B R 1 0, , T C E DCE 10 VC 1 In n o c u la t io n From Pierre Lacombe, USGS, Feb Slide 11

12 Well BRP1 CVOC Molar Concentrations: May 2005-March Injection Event May-05 8-Aug Aug Oct Dec-05 3-Apr-06 7-Jun Aug Nov Feb May-07 5-Mar-08 micromoles/liter TCE = 206 ug/l cis-dce TCE VC ethene Date Sampled Slide 12

13 Well 41BR CVOC Molar Concentrations: May 2005-March Injection Event TCE =674 ug/l May-05 8-Aug Aug Oct Dec-05 6-Mar-06 5-Jun Aug Nov Feb May-07 5-Mar-08 micromoles/liter cis-dce TCE VC ethene Date Sampled Slide 13

14 Second Donor Injection 3 yrs after initial injection July 2008 EVO added at MW-30BR by gravity injection (dghigh concentration and very tight) EVO added at BRP-1 using MW-41BR as the extraction well Slide 14

15 2 nd Injections and Downgradient Monitoring Slide 15

16 1.00E+03 Total Organic Carbon Concentrations Injection Round 1 Injection Round E+02 Concentration (mg/l) 1.00E E+00 BRP-1 16BR 30BR 38BR 41BR 74BR 1.00E-01 Slide 16

17 1.00E E+10 DHC Cells Injection Round 1 Injection Round E E+08 Concentration (cells/l) 1.00E E E E E+03 BRP-1 30BR 41BR 74BR 1.00E E E+00 Slide 17

18 1.00E+03 Sulfate Injection Round 1 Injection Round E+02 Concentration (mg/l) 1.00E E+00 BRP-1 16BR 30BR 38BR 41BR 74BR 1.00E-01 Slide 18

19 100,000 Methane Concentrations Injection Round 1 Injection Round 2 10,000 Concentration (µg/l) 1, BRP-1 16BR 30BR 38BR 41BR 74BR 1 Slide 19

20 40,000 Concentrations of CVOCs at 30BR 35,000 30,000 Concentration (µg/l) 25,000 20,000 15,000 TCE cis-dce VC Ethene 10,000 5,000 0 Slide 20

21 16000 Concentrations of CVOCs at 38BR Injection Round 1 Injection Round Concentration (µg/l) TCE cis-dce VC Ethene Slide 21

22 1.00E+02 Total Organic Carbon Concentrations at 68BR Injection Round 1 Injection Round 2 Concentration (mg/l) 1.00E E+00 68BR-B 68BR-C 68BR-D 68BR-F 1.00E-01 Slide 22

23 1.00E+03 Sulfate at 68BR Injection Round 1 Injection Round E+02 Concentration (mg/l) 1.00E+01 68BR-B 68BR-C 68BR-D 68BR-F 1.00E E-01 Slide 23

24 100,000 Methane Concentrations at 68BR Injection Round 1 Injection Round 2 10,000 Concentration (µg/l) 1, BR-A 68BR-B 68BR-C 68BR-D 68BR-F 10 1 Slide 24

25 Concentrations of CVOCs at 68BR-B Injection Round 1 Injection Round Concentration (µg/l) TCE cis-dce VC Ethene Slide 25

26 800 Concentrations of CVOCs at 16BR Injection Round 1 Injection Round Concentration (µg/l) TCE cis-dce VC Ethene Slide 26

27 700 Concentrations of CVOCs at 41BR Injection Round 1 Injection Round Concentration (µg/l) TCE cis-dce VC Ethene Slide 27

28 200 Concentrations of CVOCs at BRP Concentration (µg/l) TCE cis-dce VC Ethene Slide 28

29 Summary Fracture surface coating of EVO and bacteria an effective passive approach to bioaugmentation in fractured rock Bioaugment only once with donor replenishment yearly or less frequently Temporary recirculation using well pairs an effective distribution strategy for known connections Several wells in the pilot test area and dg are below GWQS for the first time in decades Slide 29

30 Site 2 Active Manufacturing Plant Slide 30

31 Background Site History Release of ~1500 pounds of TCE 5 to 10 ppm of TCE in clay overburden and bedrock at the source 3 ppm of TCE in DG bedrock Biodegradation daughter products and DHC bacteria present Slide 31

32 Challenges GEOLOGY!! TCE in clay overburden and fractured bedrock Expedited timeframe (3 months) for the initial source treatment Bedrock groundwater (and VOCs) discharge through seeps to an off-property stream; vinyl chloride discharge is unacceptable Slide 32

33 Approach Full Scale Injections at existing wells in source area Nov-05, Nov-06, Jul-08 EVO and KB-1 in Nov 05, EVO only thereafter to replenish electron donor Passive bioremediation as a biobarrier near the site boundary Jun-07 Addition of EVO and KB-1 at 7 locations using recirculation between groups of wells EEO KB-1 Overburden Bedrock Slide 33

34 Plume Treatment Pump between wells at least until EVO breakthrough Add KB-1 during oil injection Full-Scale Biobarrier Application (Down Gradient Plume) In one week, a 300 biobarrier was constructed using 290 gallons of EVO and 40 liters of KB-1 EEO KB-1 Overburden Bedrock Slide 34

35 Biobarrier Results biobarriers Slide 35

36 Average Results at MW-09 Series Wells (Source Area) 6000 VOC Concentration (ug/l) TCE cdce VC 0 6/1/04 6/1/05 Pump and Treat 6/1/06 Bioremediation 6/1/07 6/1/08 6/1/09 6/1/10 VC cdce TCE Slide 36

37 Average Results for MW-20 Series Wells (downgradient of biobarrier) VOC Concentration (ug/l) TCE cdce VC 6/1/04 6/1/05 Pump and Treat 6/1/06 Source Area Bioremediation 6/1/07 Biobarrier 6/1/08 6/1/09 6/1/10 VC cdce TCE Slide 37

38 Full-Scale Biobarrier Slide 38

39 Questions? Slide 39