1. Redox Tech, LLC Fundamentals of In-Situ Remediation
“Providing Innovative In Situ Soil and Groundwater Treatment”
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2. Redox Tech, LLC Business founded in 1995.
Headquarters in Cary, NC. Other offices in GA, SC, IL, MA, and CA.
New England Office opened in 2005.
In situ treatment with biological and chemical manipulation, both reduction and oxidation – over 800 projects completed.
In situ Soil Blending.
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3. In Situ Remediation is a TOOL!

4. Site Characterization for In Situ Treatment Designs
Horizontal and Vertical Delineation;
MNA Field Measurements (Ph, ORP, and DO);
Alkalinity, Dissolved Iron, Sulfate, etc…
Site Geology;
Total Oxidant Demand (TOD);
Utility Locations; and
Nearby Receptors.

5. In Situ Remediation – The Design Delivery and Chemistry are Key
Requires fundamental understanding of geochemistry and microbiology.
Requires confidence in the consultants work.
Requires delivery that mimics the target contaminant distribution.
Without both proper data, delivery and formulation, remediation likely to fail.
May require Pilot Study.
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6. Total Oxidant Demand (TOD)
Water-phase contaminant is not only material that will be oxidized
Sorbed phase contaminant
Free-phase contaminants
Naturally-occurring organic material (NOM)
Reduced soil and water minerals
Can be estimated with site data 6
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7. Total Oxidant Demand
Total Oxidant Demand can vary between <0.1 to 155 g/Kg 7
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8. Treatment Classes Chemical Oxidation Chemical Reduction
Aerobic Bioremediation
Anaerobic Bioremediation
Metals Stabilization
Thermal (steam)
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9. Chemical Oxidants
Permanganate – widely used for chlorinated alkenes, PCE, TCE, DCE, VC
Peroxide (Fenton’s) – relatively inexpensive, but can be difficult to inject
Persulfate – replacing many peroxide applications because of safety and gas generation
Ozone – still occasionally used for gas stations
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10. Base Activated Sodium Persulfate
Competes with permanganate, Fenton’s chemistry, ozone and peroxide;
Oxidizes a broader range of organic contaminants than permanganate ;
Oxidizes more compounds than Fenton’s chemistry and does not have gas generation;
Slower reaction time than other oxidants which can translate to less rebound; and
Much safer to handle than other oxidants.

11. Sodium Persulfate Injection Enfield, CT
Gasoline Release in the 1980s;
Remediation activities included product recovery, SVE, pump and treat and soil excavation;
Following 20+ years of remediation, groundwater concentration were still elevated under the roadway and nearby properties; and
Redox Tech NE was invited to bid on a Fenton’s Reagent design and proposed activated sodium persulfate as an alternative.

12. Plume is approximately 17,000 Square Feet

13. Injection Design
17,000 square foot treatment area;
Average TVOC approximately 18,000 ppb;
5 to 7 foot thickness;
44 injection points (2 rounds);
54,000 lbs of sodium persulfate;
450 gallons per point;
2 target depth intervals; and
Completed in 11 days;

14. Groundwater Treatment Results
Average TVOC approximately 4,000 ppb (78%);
Elevated sulfate still present in groundwater (>1,000 mg/L); and
22 out of 36 target monitoring wells below groundwater standards (GW Protection and Residential).

15. Groundwater Treatment Results Continued

16. Redox Tech’s Oxygen BioChem (OBC)
A slow-release oxygen generating formula designed to provide short-term chemical oxidation (1-2 months) and long term anaerobic oxidation via sulfate reduction (1-2 years)
Patented combination of sodium persulfate and food grade calcium peroxide
Can be added to excavations or injected into groundwater
One of the preferred products in New Hampshire
Predecessor to Klozur CR
Redox Tech WVRB January 2009

17. Oxygen BioChem vs. Competitors
Oxygen BioChem (OBC)
Competitors
Greater oxygen – as much as 46 wt %
Typically 10 to 20 wt %
Both chemox and biorem.
Mostly bioremediation
Greater solubility –40 wt % for the persulfate portion
Typically less than 5% soluble
Better value - $3.25 per pound
Typically $4 to $10 per pound
Redox Tech WVRB January 2009

18. Enhanced Anaerobic Bioremediation
Aquifers are sometimes limited by carbon (or food) source for bacteria
In some instances, the proper bacteria (e.g. dehalogenators) are not present
Overstimulation can result in domination by methanogens
Examples: Redox Tech’s ABC, FMC’s EHC and Regenesis’ HRC
Data should support the use these products
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19. Anaerobic BioChem (ABC)
Sodium Lactate
Ethyl Lactate – green solvent
Fatty Acids – all dissolved
Dipotassium Phosphate for micronutrients and pH buffering
Can bioaugment with RTB-1 (DHC)
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20. ABC® Advantages
Long lasting (2+ years) but water soluble so large volume of chase water not required
Lower injection pressures
Does not require hydrolysis of oils to release fatty acids
No emulsion breaking potential
No soap formation from bringing pH up to high
Demonstrated buffering
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21. Anaerobic BioChem (ABC+)
Mixture of ABC® plus zero valent iron (ZVI)
Combination of chemical reduction (ZVI) and anaerobic bioremediation
Less likely to form VC
Licensed with Adventus & Waterloo to add ZVI to carbon amendment
Injected over 1,500,000 pounds ABC+
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22. ZVI REACTION β-elimination pathway minimizes daughter products
very low concentration of chlorinated intermediates
intermediates degrade
Surface reaction at ZVI
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23. Combined Bio and Chemical Reduction
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24. ABC+ Injection Wrentham, MA
5,000 square foot area and a 15 foot thickness
Dense material with gravel, which required pre-clearing top 5 feet with auger
5,400 lbs of ABC+
18 injection points with 5 depth intervals
November 2009: PCE = 1,300 ppb and TCE = 93,000 ppb
May 2010: PCE = ND < 50 ppb and TCE = ND < 50 ppb
Dissolved gases detected and cis-1,2-DCE (3,300 ppb) and VC (910 ppb) spiked in May Cis-1,2-DEC and VC reduced in November 2010 to 670 ppb and 430 ppb.

25. Technical Advantages of Sulfate
Exists naturally in most groundwater
High solubility in comparison to other electron acceptors
Easily applied as an aqueous solution
Proper application of sulfate enhanced biodegradation will result in no adverse health effects
Results are surprisingly rapid

26. Sulfate Reduction Case Study
Site Background
Former gasoline service station with two confirmed releases in 1992 and 2001
Historical remedial efforts with limited success included groundwater pump and treat and monitored natural attenuation
Geology consists of fine to medium sand with groundwater present about 10 feet bgs
Pilot study was not intended to be a “full scale” site remediation

27. Jackson, Michigan October 3, 2007
Sulfate Depleted
In core of plume
Sulfate
Baseline Conditions
Sulfate is depleted in core
Sulfate background is > 50 ppm
Max. BTEX is >10,000 ppb
GW Flow
BTEX Plume
BTEX

28. Jackson, Michigan November 13, 2006
Sulfate
Sulfate Increases
5 weeks after first application
Sulfate is increased in core of plume – RED is >250 ppm
Concurrently BTEX >10,000 ppb is decreasing
Sulfate Depleted
BTEX
BTEX beginning to shrink

29. Jackson, Michigan January 16, 2007
Sulfate
Sulfate Increasing
3 months after initial application
Sulfate still elevated in core of plume
BTEX >5,000 ppb is shrinking
BTEX
BTEX Shrinking

30. Jackson, Michigan April 12, 2007
Sulfate
6 months after first application
Sulfate concentrations have returned to baseline conditions
BTEX plume is stable with reduced peak concentrations
Sulfate Consumed
BTEX
BTEX Rebounding

31. Jackson, Michigan Case Study
Benefits
Accelerated cleanup
Information gained significantly strengthens advocacy position with regulatory agencies
Monitoring frequency showed no lag time for acclimation of native sulfate reducing bacteria
Minimal site disruption
In-situ approach with no ongoing O&M activities
Cost effective
<$2,000 worth of materials
Safe
Demonstrated absence of hydrogen sulfide gas generation or any other adverse affects
Green – Natural Process

32. Metals Treatment Lead treatment with phosphate buffer.
Arsenic/lead treatment with phosphate, calcium buffer and hydrogen peroxide.
Hexavalent chromium treatment with ferrous chloride and hydrated lime.
Bench Scale Study

33. Steam & Recovery
Site in Lawrence, MA;
Estimated 500 gallons of No. 6 Oil;
Injected heated water into subsurface to create steam;
Project was completed in 8 days;
Approximately 700 gallons of product was recovered in 6 weeks; and
No measurable product;

34. Delivery Capabilities
Proprietary injection tools that are integrated with Geoprobe.
Permanent injection points (PVC riser and screen).
Injection of gasses, liquids and solids in largely varying geological environments - pressures from 10 to 2000 psi (Hydraulic Fracturing).
Excavations/Trenches.
In Situ Soil Blending for shallow soil (<25’ bgs.). 34
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35. Why Injection Isn’t for Amateurs35

36. Pump and Treat Gone Bad 36

37. Hydraulic Fracturing
Injection of water, solution or slurry at pressure that exceeds the lithostatic pressure and cohesive strength of the formation.
Results in short-term enhancement of soil permeability.
Increases radius-of-influence and injection rate. 37
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38. Hydraulic Fracturing Concept

39. Pressure – Time History
Fracture
Maintenance

40. ABC+ Injection Equipment40
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41. In Situ Soil Blending
Efficient and uniform delivery of remediation amendments
Production rates comparable to dig, haul and backfill
No long term liability associated with disposal
Costs that can be 2 to 10 times less expensive than dig and haul, depending upon the extent of contamination
No RCRA TSD permits are required
Can treat a wide range of compounds, such as chlorinated solvents, pesticides, PAHs, etc 41
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42. In Situ Soil Blending – The Beginning42
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43. In Situ Soil Blending - Improved43
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44. Improvements in Blender
Weight reduced by ~50% which reduces transportation costs by factor of two ($5-6 per mile now)
Horsepower approximately doubled
Independent acting dual motors in custom designed mixing head
Torque load sensing on both sides of head so rotation speed automatically adjusts – prevents “deadheading”
Base is common excavator so parts readily available 44
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45. In Situ Soil Blending Cambridge, MA Dichloroethane (DCA) Contamination45
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46. Post In Situ Soil Blending46
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47. Completely Integrated with Geoprobe
Amendment Distribution via Electrical Conductivity Distribution Dr. Joseph Rossabi
Completely Integrated with Geoprobe
Apply AC (current)
Measure DC (voltage)
Know current and voltage, calculate resistance and convert to conductivity (inverse relation)
Measurements every 0.05 ft (vertical)
Lateral sensitivity < 0.5 ft 47
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51. USEPA Site Rhode Island51

52. Treatment Area 52

53. Blending Activity – Day 1
Top Photo – A view of the excavation prior to blending activity
Bottom Photo – A view of the application of the first 1K pounds of KMnO4 53

54. Blending Activity – Day 1 (Continued)
Top Photo – A view of the initial mixing with an excavator.
Bottom Photo – A view of the soil blending thoroughly mixing the KMnO4 with the contaminated soil. 54

55. Day 1 – Area Completed
2,000 pounds of KMnO4 blended with ~ 300 cy of contaminated soil (Area shaded in purple).
KMnO4 not observed in down gradient monitoring wells. 55

56. Day 5 – Area Completed
7,000 pounds of KMnO4 blended with ~ 1,500 cy of contaminated soil (Area shaded in purple).
Approximately 8,500 gallons of water was used to blend the KMnO4 with the soil.
KMnO4 observed in 3 down gradient monitoring wells ( ). 56

57. Day 7 – Soil Blending Completed
10,000 pounds of KMnO4 blended with ~ 2,100 cy of contaminated soil (Area shaded in purple).
Approximately 10,500 gallons of water was used to blend the KMnO4 with the soil.
KMnO4 observed in 4 down gradient monitoring wells ( ). 57

58. Day 12 – Post Blending Monitoring
KMnO4 observed in 7 monitoring wells ( ). 58

59. In Situ Remediation Issues
Underestimated contaminant mass;
Unknown underground structures;
Poorly marked utilities;
Daylighting;
Back Pressure;
Surface grade;
Aboveground obstructions; and
Poorly identified geology

60. The End Injection is not the only application technique;
In Situ Remediation is 1 of many tools;
Injection is not the only application technique;
Know your site;
Work with your In Situ contractor;
Understand the function of the chemical; and
For more information:
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