B-27, in: H.V. Rectanus and R. Sirabian (Chairs), Bioremediation and Sustainable Environmental Technologies—2011. International Symposium on Bioremediation and Sustainable Environmental Technologies (Reno, NV; June 27–30, 2011). ISBN 978-0-9819730-4-3, Battelle Memorial Institute, Columbus, OH. www.battelle.org/biosymp

Injection of Oxygen in Deep Horizontal Wells for the Biostimulation of PAH Degradation at a Former Wood-Treating Superfund Site

Cal Butler and Ernest Mott-Smith (Black & Veatch, Tampa, Florida, USA) Timothy R. Turner (Black & Veatch, Alpharetta, Georgia, USA) Erik Spalvins (EPA Region 4, Atlanta, Georgia, USA) Sean R. Carter (Matrix Oxygen Injection Systems, LLC, Henderson, Nevada, USA)

Background/Objectives. The Escambia Wood Treating Company (ETC) site is a former wood-preserving facility located in Pensacola, Florida that operated from 1942 through 1982. ETC treated wood products with coal tar creosote and PCP. Process waste water including spent creosote and PCP were disposed in an unlined waste pond. NAPL migrated from the waste pond vertically to over 100 ft bgs. The site is underlain by com- plex sequence of sand, gravel, silt and thin lenses of clay in three defined zones; surficial, low permeability (LPZ) and main producing zones. This aquifer is the primary municipal drinking water supply. A dissolved SVOC plume (primarily naphthalene), up to a quar- ter-mile wide and one-mile long, and 200 ft deep extends downgradient from the ETC source area. An active railroad switching yard is located adjacent to and downgradient of the on-site source area. Approach/Activities. In situ bioremediation with aerobic biobarriers was selected in the Feasibility Study to remedy the extended plume. A pilot study was prepared for beneath the rail yard to evaluate the site-specific oxygen transfer efficiency and effec- tiveness of the remedy. Three bundled horizontal wells were used to infuse oxygen into the LPZ. The pilot study included pulsing oxygen into the infusion wells during two phases, including a 30-day period in July 2009 and a 90-day period in June 2010. A 1,450 foot horizontal bore was advanced to a depth of 100 ft bgs. Three 2-inch diameter injection wells, each 170 foot long, were installed within the bore using hori- zontal directional drilling (HDD). The screens were constructed with different slots and materials (stainless steel, ADS HDPE flex pipe) to assess optimal well construction materials. Performance monitoring wells were installed at depths of 55, 71 and 91 feet and at distances of 5, 15, and 20 feet from the injection wells. Oxygen was produced on- site using a pressure-swing adsorption oxygen generator. The 90% oxygen was injected from a storage tank at mass injection rates up to 113 pounds/day per injection well. The oxygen was pulsed into the horizontal infusion wells at variable durations to assess opti- mization of bioremediation. Pilot test results were attained through groundwater monitor- ing of downgradient wells, including SVOC analyses, qPCR analyses of aerobic bacteria (bioflow filters and biotraps), continuous downwell DO and ORP field monitoring, and general chemistry parameters before, during, and after pilot testing. Results/Lessons Learned. The pilot study produced essential information for the upcoming full scale aerobic biobarrier design based on additional horizontal oxygen infusion wells. The use of a carrier casing and biopolymer drilling fluids during HDD contributed to a successful installation. The oxygen feed system ran flawlessly and was easily adjusted via a remote PLC system. During the one month pilot study, DO increased from near 0 to at least 52.5 mg/L at a depth of 91 feet. Solubility was calculated at 56 mg/L for this depth. DO increased to 10 mg/L or higher at depths of 55 and 71 feet. A corresponding increase in oxidation-reduction potential up to 200 mV and a tenfold increase in dissolved carbon dioxide were also measured. Laboratory analyses showed up to 4 orders magnitude increase in aerobic bacteria, with an overall reduction in dissolved naphthalene of 50 to 95 percent during oxygen infusion. The test demonstrated that a successful aerobic barrier was created throughout the 55-foot water column and outward to at least 20 feet, with a minimum DO of 10 mg/L. The data indicate that an oxygen reservoir was created, oxygen demand was significantly reduced, and periodic pulse injections are effective in maintaining highly aerobic conditions. Post pilot test monitor- ing has attested to the longevity of elevated DO in the LPZ, and limited naphthalene rebound from the source. Injection of Oxygen in Deep Horizontal Wells for the Biostimulation of PAH Degradation at a Former Wood Treating Superfund Site

Ernest Mott-Smith, P.E. BLACK & VEATCH FEDERAL Cal Butler, P.G. SERVICES DIVISION Tim Turner, P.E.

Erik Spalvins, EPA Region 4 June, 2011 • Reno David Keefer, EPA Region 4 Sean R. Carter, Matrix Oxygen Injection Systems ESCAMBIA WOOD TREATING SITE

Background • Former wood treating facility in Pensacola, FL that operated from 1942 to 1982 • Primary products were pressure treated utility poles. • Primary contaminants are coal tar creosote compounds, PCP and dioxin • Site is 26-acres, with over 60 acres of adjacent Active Wood Treating Plant neighborhoods acquired. circa 1975

BACKGROUND

2

BACKGROUND ??? 3 ESCAMBIA WOOD TREATING SITE – JAN 2009

Active Businesses Adjacent to Site Clean Soil Stockpile WTP Ops

Source Area SWMU 10 Containment Cell #1 Containment Cell #2

Mount Dioxin Direct Disposal (20-feet High) 0 90 180

Scale (feet) BACKGROUND Relocation of Mount Dioxin and Source Area Locations 4 B&V16 November 2010

Composite Depth Naphthalene Plume

0 1,300

Scale in Feet BACKGROUND

5 Site Conceptual Model

~330-feet ~600-feet CHAIN LINK FENCE CHAIN LINK FENCE A (Surrounding SWMU 10) (Property Boundary) A’ PMW

West PMW East - CSX RAILROAD SWITCHING YARD - = 20 PARALLEL TRACKS Cluster Cluster HW3 MW27D MWSB03 HW2 PMWA Cluster 0 SWMU 10 NAPL SOURCE SYCAMORE 80 STREET 10 (Former ETC Impoundment)

70

20 / TW02 / SB04 SB02

60

30 TarGOST RDCPT07 50

40

6,600 40 8,125 50 GROUND WATER FLOW DIRECTION 670 ND 1,100 Surficial ND 30 60 Zone SZ 10,000 20 LPZ 70 SZ 13,000 2,200 LPZ 19,400 SZ 4,000 LPZ 10 80 Biosparge Horizontal Well 0 Temp 19,000 2,900 90 Well w FEET BELOW GROUND SURFACE 25,200 4,900 NAPL

No -10 Sample 100 Installed Oct ‘10 SEA LEVEL MEAN FEET IN ELEVATION 8,900 -20 10,000 10,711 Legend 110 Silty Sandy Low CLAY & = NAPL CLAY CLAY 30 120 Permeability Clayey Sandy SILT or Nov 2010 Flowing -40 LPZ SILT Silty VFG SAND Water Table NAPL Zone 130 MPZ Silty Clayey Gravelly SAND LPZ -50

SAND SAND SAND 140 MPZ 2009 Estimated SVOC Main Producing 2009 naphthalene (top) -60 19,000 + total SVOC (bottom) isoconcentration ? 25,200 10,000 150 Zone results in ground water contour in ground ? water in ug/L in ug/L -70 1.2 J 160 1.2 J Notes: Geology was taken from sonic boring logs, and is therefore conceptualized between borings; SZ = Surficial Zone J = estimated core was restricted to the screened zones at HW2-PMW and HW3-PMW. LPZ = Low Permeability Zone VFG = very fine-grained -80 RDCPT07 was a advanced with a CPT probe coupled with tar-related green optical scanning tool (TarGOST). MPZ = Main Producing Zone ug/L = micrograms per liter Solid Waste Management Unit (SWMU)10 has been enlarged to the west and excavated to the water table. NAPL = Non-Aqueous Phase Liquid SVOC = semi-volatile organic compounds

BACKGROUND

6 Source Zone DNAPL DNAPL at 70 ft bgs Adjacent confirmatory

50% RE sonic bore; cores and plastic sleeves stained dark brown to black; strong naphthalene odor.

Adjacent test well screened 70 to 75 ft bgs with free flowing creosote DNAPL.

TD = 85’

TarGOST Source Boring (CPT Rig) (CPT Boring Source TarGOST

► BACKGROUND

7 Biosparge Pilot Test Setup

8 BIOSPARGE PILOT TEST GOALS

1. Demonstrate viability of directional drilling under railroad yard 2. Compare the effectiveness of different well materials 3. Evaluate the ability to disperse oxygen effectively through a horizontal well 4. Determine design basis for flows and pressures

5. Measure and assess dissolved oxygen dispersion outward and upward from the horizontal wells 6. Identify changes in microbial activity due to oxygenation of the plume

BIOSPARGE PILOT TEST SET TEST - UP PILOT BIOSPARGE

9 NAPTHALENE PLUME

CSX Dissolved Plume in the Railroad Low Permeability Zone Switching Yard

Source Zone

Wood Treating HDD Well Site 0 500

Scale in Feet BIOSPARGE PILOT TEST SET TEST - UP PILOT BIOSPARGE

10 LAYOUT OF IN SITU BIOSPARGE PILOT TEST

Railroad Switching Yard NAPL Source Area

Two Sets of Three Monitoring Wells at Different Depths to Gauge Pilot Test Performance Former Wood Treating Site Horizontal Injection Well with Three 0 250 Screen Intervals Scale in Feet BIOSPARGE PILOT TEST SET TEST - UP PILOT BIOSPARGE

11 Performance Monitoring Wells

HW-3 Performance Directional Monitoring Array Railroad Drilled Well

Switching 5-feet Yard HW-3A (91 ft bgs)

HW-3B (71 ft bgs)

HW-3C (55 ft bgs)

0 ~30

Scale in Feet BIOSPARGE PILOT TEST SET TEST - UP PILOT BIOSPARGE

12 In Situ Biosparge Pilot Study Components

Bundle of 3 Horizontal Directional Rig drilling Air Conversion to Injection the 1,450 ft long bore to 100 ft bgs, >90% Pure O Wells 2 and installing the bundle of three (3) injection well screens.

Matrix LLC

O2 Injection Trailer Railroad Switching Yard with 20 Parallel Tracks

Oxygen Infusion O2

Three bundled well screens @ BIOSPARGE PILOT TEST SET TEST - UP PILOT BIOSPARGE 170’ per screen = 510’ of total screen length

13 Pilot Scale Biosparge Wall Design

Select Screen Determine O Determine Flux 2 Length and Injection Rate of SVOCs Diameter Requirement Plume Geometry

Select Slot Select Slot Size Spacing Select O2 Grain Sieve Injection Flow Open Area Analysis Rate Calculation

Determine Select Well Materials Friction Losses Prepare Bore Minimize Siltation Plan and Consider Non-Corrosive Assembly Plan Siltation/Blockage Flexible BIOSPARGE PILOT TEST SET TEST - UP PILOT BIOSPARGE

14 BioSparge Well Construction Screen Construction ADS piping is air cut microslits on 1-foot centers that delivers 0.2 scfm per foot of pipe (opens at 5 psig). O2 HDPE Riser

566-feet Grout Seal

170-feet 28-feet

SS Riser

12-inch Borehole 2-Inch ADS HDPE DR-11 2-Inch Stainless Steel 8-inch Casing Air Diffusion Pipe Screen Slot

BIOSPARGE PILOT TEST SET TEST - UP PILOT BIOSPARGE (Withdrawn)

15 Oxygen Injection Trailer

• The Matrix Oxygen Injection System produces O2 gas on-site for pulse injection into groundwater contaminant plumes at controlled rates or volumes. • DO saturation levels up to 40 mg/L.

• Dispersion of oxygen with control of radius Trailer Mounted Matrix of influence and oxygen mass transfer Oxygen Injection System • Used at over 250 remediation sites over 14 years. • U.L. certified PLC control system with touch screen display and remote access • Pressure swing adsorption oxygen generator and rotary screw compressor

BIOSPARGE PILOT TEST SET TEST - UP PILOT BIOSPARGE • License to operate under U.S. Patent No. 5,874,001.

16 Oxygen Injection Flow Schematic

Ambient Air Nitrogen Gas (Purged)

Pressure Swing Adsorption Oxygen Generator Oxygen Storage Tanks for Pulse Injection

Rotary Screw Air Compressed Air, Compressor and Clean & Dry Refrigerated Dryer Oxygen Gas ~90% Oxygen Pulsed Into

Groundwater

Oxygen Delivery BIOSPARGE PILOT TEST SET TEST - UP PILOT BIOSPARGE Manifold 17 Naphthalene Aerobic Degradation Pathway

Source: Dr. Larry Wackett, University of Minnesota, 2009 based upon the work of Eaton et al., 1992

BIOSPARGE PILOT TEST SET TEST - UP PILOT BIOSPARGE

18 Results

19 Verification of Dissolved Oxygen Front

Used stable luminescent optical dissolved oxygen probes • Continuous downwell monitoring with Trolls for 30-days in the 6 performance monitoring wells for DO, ORP, pH, conductivity, and temperature.

• DO Measurement a critical parameter • Oxygen is not consumed as part of an electrochemical reaction, and optical sensors do not require sample flow or stirring for accurate readings • Accuracy from: • 0 to 20 mg/L (±0.1 to 0.2 mg/L )

BIOSPARGE PILOT TEST MONITORING TEST PILOT BIOSPARGE • 20 to 50 mg/L (±10% )

20 Phase 1 and 2 Pilot Scale Oxygen Feed Rates Phase I Phase II 120

100

O2 O2 Injection 80 Rate (lbs./day) Goal HW1 - O2

60 HW2 - O2

40 HW3 - O2

20

0 07/24/09 - 08/06/09 to 08/22/09 to 06/17/10 to 07/21/10 to 08/06/09 08/22/09 06/17/10 07/21/10 09/14/10 BIOSPARGE PILOT TEST RESULTS TEST PILOT BIOSPARGE • In situ DO target = 10 mg/L (minimum goal of 5 mg/L) 21 Phase 1 and 2 Pilot Scale Flow Results

18 Phase I Phase II

16

14

12 O2 Flow Rate Flow HW1 - Flow (scfm) 10 Goal

8 HW2 - Flow

6 HW3 - Flow 4

2

0 07/24/09 - 08/06/09 to 08/22/09 to 06/17/2010 to 07/21/10 to 08/06/09 08/22/09 06/17/10 07/21/10 09/14/10

BIOSPARGE PILOT TEST RESULTS TEST PILOT BIOSPARGE • 0.03 to 0.1 scfm/foot of screen • Pressures ranged from 30 to 53 psig 22 Performance Monitoring Wells

HW-3 Performance Directional Monitoring Array Railroad Drilled Well

Switching 5-feet Yard HW-3A (91 ft bgs)

HW-3B (71 ft bgs)

HW-3C (55 ft bgs)

0 ~30

Scale in Feet BIOSPARGE PILOT TEST MONITORING TEST PILOT BIOSPARGE

23 Phase 1 and 2 Pilot Scale DO Results – HW3

DISSOLVED OXYGEN AT HW3 60.0 O2 Phase 1 Monitoring O2 Phase 2 Monitoring

50.0

40.0

30.0

20.0

10.0 DO Goal Dissolved Oxygen (mg/L) Oxygen Dissolved 0.0 05/27/09 07/26/09 09/24/09 11/23/09 01/22/10 03/23/10 05/22/10 07/21/10 09/19/10 11/18/10 01/17/11 03/18/11 05/17/11 HW3-91' HW3-71' HW3-55' • Phase 1 = 30 days injection • Phase 2 = 89 days injection BIOSPARGE PILOT TEST MONITORING TEST PILOT BIOSPARGE

24 Phase 1 and 2 Pilot Scale DO Results – HW2

O2 Phase 1 Monitoring O2 Phase 2 Monitoring

DO Goal

• Phase 1 = 30 days injection • Phase 2 = 89 days injection BIOSPARGE PILOT TEST MONITORING TEST PILOT BIOSPARGE

25 Phase 1 and 2 Pilot Scale ORP Results

Oxidation Reduction Potential at HW2 400 O2 Phase 1 Monitoring O2 Phase 2 Monitoring 300

200

100

0

ORP (mV) -100

-200

-300 03/28/09 07/06/09 10/14/09 01/22/10 05/02/10 08/10/10 11/18/10 02/26/11 06/06/11 HW2-91' HW2-71' HW2-55'

• Phase 1 = 30 days injection • Phase 2 = 89 days injection BIOSPARGE PILOT TEST MONITORING TEST PILOT BIOSPARGE

26 Sampling for In Situ Microbial Population

Bio-Flo Samplers Bio-Trap® Samplers • Field sample collection • Contains beads of activated • Used to record baseline & carbon with high surface area post-pilot test populations for microbial growth of degraders • ~30-day incubation • 1 to 2 Liters • Unique sampling matrix, • Microbes live on solid bio‐sep beads, which mimics surface environmental conditions

Bio-Flo Sampler • Can be analyzed using a variety of molecular based approaches (DNA, RNA and PLFA) BIOSPARGE PILOT TEST MONITORING TEST PILOT BIOSPARGE

27 Downwell Microcosm Study - Phase 1 Injection

PHE PHE (cells/mL) NAH (cells/mL)NAH

BASELINE

• Microcosm study consisted of Bio-trap cylinders installed in 3 HW-3 wells for one month • Baseline results from Bio-Flo Sampler BIOSPARGE PILOT TEST MONITORING TEST PILOT BIOSPARGE NAH = Naphthalene Dioxygenase PHE = Phenol Hydroxylase 28 NAH Indicator Gene Populations by qPCR

1.00.E+10

Phase 1 O2 Phase 2 O2 Injection Injection

1.00.E+09 HW2-71 NAH

HW3-71-NAH

HW2-91 NAH HW3-91 NAH

NAH (cells/ml) NAH 1.00.E+08 BASELINE

1.00.E+07 05/27/09 07/26/09 09/24/09 11/23/09 01/22/10 03/23/10 05/22/10 07/21/10 09/19/10

BIOSPARGE PILOT TEST MONITORING TEST PILOT BIOSPARGE Bio-Flo Sampling NAH = Naphthalene Dioxygenase 29 Phase 1 Pilot Scale Respirometry Data

Phase 1 Respirometry at HW3

• Wellhead CO2 Analysis • 500 ppmv is background value in air Phase 1 Respirometry at HW2 BIOSPARGE PILOT TEST MONITORING TEST PILOT BIOSPARGE

30 Naphthalene Analytical Sampling

PHASE 1 PHASE 2 INJECTION INJECTION

Mar-11

Mar-11 BIOSPARGE PILOT TEST MONITORING TEST PILOT BIOSPARGE

31 Conclusions and Lessons Learned

• Directional drilling of 1450-ft long and 100-foot deep cluster biosparge well was very successful. • ADS Sparge pipe proved effective. • Additional performance monitoring wells would greatly enhance determination of the lateral influence of dissolved oxygen and naphthalene-consuming bacteria. • Vertical biosparging wells would serve to compare the HDD effectiveness and cost for full-scale operation. • The optical DO downwell probes on the trolls maintained calibration through 90 days of operation. • Good convergence of data for pilot test success:

Analytical results Field DO and ORP data RESULTS Bacterial microcosm Respirometry results 32 Contact Information: Timothy R Turner, PE Black & Veatch Special Projects Corp. 1120 Sanctuary Parkway, Suite 200 Alpharetta, Georgia 30004 770-521-8125 33