Steam Enhanced Remediation In Fractured Rock · Steam Enhanced Remediation In Fractured Rock ... Gorm Heron, Scientist/Engineer Hank Sowers, CEO/Chief Operator Dacre ... SteamTech

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Steam Enhanced Remediation

In Fractured Rock

(and a little about the other sites)

Gorm Heron, Scientist/Engineer

Hank Sowers, CEO/Chief Operator

Dacre Bush, Geologist/Program Manager

Gregg Crisp, Site manager

SteamTech Environmental Services

Bakersfield, CA

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Creosote DNAPL to +140 ft depth

Alluvial sands and gravels with clays

Both LNAPL and DNAPL

Approaching MCLs in 2002

Craig Eaker, SCE

160,000 gallons removed from subsurface

In-situ destruction significant

UC Berkeley � LLNL - SCE

Visalia Pole Yard

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Alameda Point

Alameda Point (Berkeley Environmental Restoration Center)

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Edwards AFB Site 61

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Beale AFB

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Loring: Fractured limestone

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Florida site! Full-scale clean-up with performance guarantee

! Steam enhanced remediation and electrical heating

! Tight pneumatic and hydraulic control

! Stimulated oxidation reactions for reduction of TPH concentrations in oily areas

! Detailed subsurface monitoring (temperature and electrical resistance tomography)

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Extraction well with Hawthorn electrode

(EE)

Clay

Sand

Area A steam injection well with Hawthorn electrode (SE)

Perimeter steam injection wells (SI) Steam

Electrode

Electrode

Deep electrode

(DE)

Well types

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Preliminary results, Edwards AFB

Acknowledgments to:

� Stephen Watts, Edwards AFB project manager

� Dave Leeson, AFCEE

� Scott Palmer, Earth Tech project manager

� Gregg Crisp, site manager and operator

� Layi Oyelowo, Edwards AFB

Results are preliminary, conclusions have not been published or confirmed by the above persons

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Fractured granite(quartz monzonite)

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Objectives/questions�Will SER be effective for removal of VOCs from fractured rock atEdwards AFB?

�How is the DNAPL mobilized and extracted?

�What are the ultimate VOC cleanup levels that can be expected atEdwards AFB using SER?

�How rapidly will the steam heat Site 61 at Edwards AFB?

�How should steam injection and extraction well-fields be designed for optimum performance at Edwards AFB?

�What is the optimal steam injection and extraction strategy for DNAPL in fractured rock at Edwards AFB?

�How long will the site stay hot after completion of the steaming?

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Weathered zone

Fractured granite

30 ft

Hydrogeology

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???

TCE distribution

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Vertical distribution of contaminants before operations: PID readings on cores

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

0 5 10 15 20 25 30 35Depth below grade (ft)

PID

read

ing

(ppm

)B13 B14

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Extraction and steam injection wells

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Injection well

design

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10

20

60

50

40

30

High-temperature grout (9 ft)

High-temperature grout (5 ft)

High-temperature grout (5 ft)

Coarse sand/gravel (9 ft)

Fine sand (3 ft)

#1/20 Fine sand (3 ft)

Fine sand (2 ft)

Fine sand (2 ft)

Coarse sand/gravel (13 ft)

Coarse sand/gravel (11 ft)

Wea

ther

ed z

one

(app

roxi

mat

ely

35 ft

)Fr

esh

bedr

ock

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23

12

9

52

45

65

26

31

50

#1/20 Fine sand (3 ft)

Deep injection screen (58 to 60 ft)

Middle injection screen (38 to 40 ft)

Top injection screen (18 to 20 ft)

Dep

th b

elow

gra

de (f

t)

Note: Thermocouples were attached at 5 ft intervals from 5 ft below grade to 45 ft below grade, and at 49 ft, 52 ft, 55 ft and 60 ft.

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Strategy

Vacuum test: Vapor capture radius ~ 80 ft

Initially steam injection deep only, extraction shallow

Air co-injection

Extract 25 to 50 % more than injected

Monitor carefully and adjust strategy

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VEA-5

VEA-4

VEA-3 VEA-1

VEA-2

EW-1

EW-3

EW-2

EW-4

TMA-A

TMA-D

TMA-C

TMA-B

IW-1

Subsurface monitoring network

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ERT data planes

VEA-5

VEA-4

VEA-3 VEA-1

VEA-2

ERT data planes

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Example ERT data plane6/10 6/23 6/27 7/6 7/10

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30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70

Tem

pera

ture

(OC

)

6/2

6/9

6/10

6/11

6/12

6/14

6/17

Depth below grade (ft)

Thermocouple data

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24

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70

Tem

pera

ture

(OC

)

6/2

6/9

6/10

6/11

6/12

6/14

6/17

6/20

6/21

6/22

Depth below grade (ft)

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25

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70

Tem

pera

ture

(OC

)

6/2

6/9

6/10

6/11

6/12

6/14

6/17

6/20

6/21

6/22

6/23

6/28

Depth below grade (ft)

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Water balance

0

20,000

40,000

60,000

80,000

100,000

120,000

5/20 5/23 5/26 5/29 6/1 6/4 6/7 6/10 6/13 6/16 6/19 6/22 6/25 6/28 7/1 7/4 7/7 7/10 7/13 7/16 7/19

Tota

l vol

ume

(gal

lons

)

Total pumped from EW's

Total steam injected (as water)

Net extraction

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Energy balance

0

50

100

150

200

250

300

350

400

5/20 5/23 5/26 5/29 6/1 6/4 6/7 6/10 6/13 6/16 6/19 6/22 6/25 6/28 7/1 7/4 7/7 7/10 7/13 7/16 7/19

Cum

ulat

ive

ener

gy c

onte

nt (m

illio

n B

TU)

Energy injected as steam

Energy extracted as condensate

Energy in pumped water

Energy in extacted vapors

Total energy extracted

Energy stored in formation

Energy balance

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Vapor flow rate and PID readings

648

0

200

400

600

800

1,000

1,200

1,400

1,600

5/20 5/23 5/26 5/29 6/1 6/4 6/7 6/10 6/13 6/16 6/19 6/22 6/25 6/28 7/1 7/4 7/7 7/10 7/13 7/16 7/19

Mas

s of

TC

E re

mov

ed in

vap

or (l

bs)

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

PID

read

ing

at V

-1 (p

pmv)

lbs

ppmv

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Headspace PID screenings on grab water samples

0

500

1,000

1,500

2,000

2,500

3,000

3,500

5/20 5/23 5/26 5/29 6/1 6/4 6/7 6/10 6/13 6/16 6/19 6/22 6/25 6/28 7/1 7/4 7/7 7/10 7/13 7/16 7/19

PID

hea

dspa

ce re

adin

g (p

pmv)

L-1

EW-1

EW-2

EW-3

EW-4

Headspace PID data

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Recovery of NAPL

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Results� Successful treatability study - great data

� Steam heated site partially, and accelerated mass removal

� More than 700 lbs of VOCs removed

� NAPL recovered where no NAPL was expected

� Air injection promising for opening fractures to steam flow, and potentially for reducing risk of NAPL condensation

� ERT apparently valuable at Edwards: Heated zones showed large changes in electrical resistivity

� Very uneven steam distribution: Increased focus on temperature monitoring, also in extraction wells