Direct Push Optical Screening Tool for

Chlorinated Solvent DNAPL

Randy St. Germain, Dakota Technologies, Inc.Murray Einarson & Adrian Fure, AMEC Geomatrix

2011 North American Environmental Field Conference and Exposition 2

presentation summary

• NAPL heterogeneity

• LIF technology review

• innovative use for LIF (chlorinated DNAPL)

• recent results of prototype testing

2011 North American Environmental Field Conference and Exposition 3

NAPL architecture not nearly as simple as we often assume even after years of lectures, papers, alerts, ‘shouting from the hill tops’

heterogeneity remains this industry’s inconvenient truthwhen discussing ISCO, recovery, slurry walls, etc.

OSTs such as ROST, UVOST, and TarGOST have shown:

• LNAPLs and DNAPLs rarely exist as simple “layers” as once shown in textbooks and guidance documents – even the ‘pregnant LNAPL pancakes’ error on the side of simplicity

• both LNAPLs and DNAPLs follow geology/lithology closely (porosity of sand can vary – see pic of dye-stained gasoline)

• LNAPL architecture found with OSTs is often strange (even find LNAPL 20-30 ft below groundwater)

• OSTs, tracer studies, MIP, other high resolution tools showing we have to go back to basics and start including geology’smajor role in NAPL distribution

• separate phase NAPLs simply disperse less than dissolved• rarely does just chemistry or just geology properly define the

NAPL CSM – it takes both - along with lots and lots of data

representative sample zone?

John Mosquera

2011 North American Environmental Field Conference and Exposition 4

let’s review the basics of optical screening tools…• spectroscopic (light-based)

• OSTs employ a sapphire-windowed probe

• require “direct push” delivery – both dynamic (Geoprobe®/AMS) and static (CPT)

• log a light-based phenomenon vs. depth (usually fluorescence of PAHs)

• sometimes referred to collectively as “LIF” (laser-induced fluorescence) – but inaccurately so, since some use Hg-lamp (or modified with LEDs)

windowed probe - percussion windowed probe – submerged derrick windowed CPT “sub” above CPT

2011 North American Environmental Field Conference and Exposition 5

A/D

remote display

stringpot

split caprods

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laser

scope

e-deck pc

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printer

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fiberoptics

the basics of optical screening tools

2011 North American Environmental Field Conference and Exposition 6

Real-Time In-Situ Characterization

Detailed Conceptual Model

higher quality informationfor higher quality engineering/decisions

Optical Screening Tools produce footage very rapidlywith real time results to guide the investigation

2011 North American Environmental Field Conference and Exposition 7

OSTs are flexible… deployable under variety of delivery platforms and conditions

Brodhead Creek

• Geoprobe®, PowerProbe, CPT, even drill rigs (in soft materials)

• on-shore, off-shore, ice, bogs, sediments, tar pits, settling ponds

• rain, snow, sleet, sun, wind, hot, cold

TIP: no “poor recovery” with OSTs… and NAPLs usually reside in poor recovery prone matrices

2011 North American Environmental Field Conference and Exposition 8

5-day TarGOST investigation at a coal tar DNAPL siteremember that coal tar and creosotes ARE most often DNAPLs too!

Dakota has characterized over 100 DNAPL sites with TarGOST

Day 1

2011 North American Environmental Field Conference and Exposition 9

5-day TarGOST investigation at a coal tar DNAPL siteremember that coal tar and creosotes ARE most often DNAPLs too!

Dakota has characterized over 100 DNAPL sites with TarGOST

Day 1Day 2

2011 North American Environmental Field Conference and Exposition 10

5-day TarGOST investigation at a coal tar DNAPL siteremember that coal tar and creosotes ARE most often DNAPLs too!

Dakota has characterized over 100 DNAPL sites with TarGOST

Day 1Day 2Day 3

2011 North American Environmental Field Conference and Exposition 11

5-day TarGOST investigation at a coal tar DNAPL siteremember that coal tar and creosotes ARE most often DNAPLs too!

Dakota has characterized over 100 DNAPL sites with TarGOST

Day 1Day 2Day 3Day 4

2011 North American Environmental Field Conference and Exposition 12

5-day TarGOST investigation at a coal tar DNAPL siteremember that coal tar and creosotes ARE most often DNAPLs too!

Dakota has characterized over 100 DNAPL sites with TarGOST

Day 1Day 2Day 3Day 4Day 5

2011 North American Environmental Field Conference and Exposition 13

5-day TarGOST investigation at a coal tar DNAPL siteremember that coal tar and creosotes ARE most often DNAPLs too!

Dakota has characterized over 100 DNAPL sites with TarGOST

hi-resolution 3D OST data provides information useful for…

• MNA studies• recovery/monitoring well placement

• dig/haul design/costing• trenching design

• containment design• thermal design

• in situ chemical oxidation injection• groundwater sampling guidance

• soil engineering sampling guidance

2011 North American Environmental Field Conference and Exposition 14

OSTs work because the PAHs in NAPLs fluorescethis provides a convenient way to detect NAPLs by their “glow”

shortUV

longUV

kero

sene

gaso

line

dies

el

oil

2011 North American Environmental Field Conference and Exposition 15

OSTs work because the PAHs in NAPLs fluorescethis provides a convenient way to detect NAPLs by their “glow”

shortUV

longUV

kero

sene

gaso

line

dies

el

oil

2011 North American Environmental Field Conference and Exposition 16

OSTs work because the PAHs in NAPLs fluorescethis provides a convenient way to detect NAPLs by their “glow”

shortUV

longUV

kero

sene

gaso

line

dies

el

oil

2011 North American Environmental Field Conference and Exposition 17

OSTs work because the PAHs in NAPLs fluorescethis provides a convenient way to detect NAPLs by their “glow”

shortUV

longUV

kero

sene

gaso

line

dies

el

oil

2011 North American Environmental Field Conference and Exposition 18

unfortunately, chlorinated solvents don’t fluorescebut indicator dyes are a common way to detect DNAPLs

test tube containing moist Fisher sea sand3 tubes on the right contain dyes mixed in the sand

then TCE was poured in from top

2011 North American Environmental Field Conference and Exposition 19

unfortunately, chlorinated solvents don’t fluorescebut indicator dyes are a common way to detect DNAPLs

test tube containing moist Fisher sea sand3 tubes on the right contain dyes mixed in the sand

then TCE was poured in from top

2011 North American Environmental Field Conference and Exposition 20

unfortunately, chlorinated solvents don’t fluorescebut indicator dyes are a common way to detect DNAPLs

test tube containing moist Fisher sea sand3 tubes on the right contain dyes mixed in the sand

then TCE was poured in from top

2011 North American Environmental Field Conference and Exposition 21

unfortunately, chlorinated solvents don’t fluorescebut indicator dyes are a common way to detect DNAPLs

test tube containing moist Fisher sea sand3 tubes on the right contain dyes mixed in the sand

then TCE was poured in from top

2011 North American Environmental Field Conference and Exposition 22

‘DYE-LIF’ probe

• simple “add-on” to mature LIF technology

• port below sapphire window introduces a DNAPL fluorescing dye

• once solvated in DNAPL, the dye fluoresces, allowing for detection with conventional LIF system

2011 North American Environmental Field Conference and Exposition 23

recent prototypes

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2011 North American Environmental Field Conference and Exposition 24

TarGOST HD?High Definition or High Density OST

because it might well be necessary to spot tiny DNAPL ‘ganglia’

test pattern printed on poster stock scanned past sapphire window at 2cm/sec

resulting TG-HD log of fluorescing paper lines detected down to .005” wide!

2011 North American Environmental Field Conference and Exposition 25

quantitative (and temporal) results for TCE

TarGOST HD™ log • 200 ul of dye solution placed on sapphire window ‘miniwells’

• sand/TCE samples then placed on the sapphire window over top of dye solution – a backwards simulation of dye solution being injected into the sand/TCE

• ~ 3seconds elapsed time in each sample zone demonstrates fast ‘melt’ of dye into TCE… more than the time needed for window to travel down to meet injected dye

• TarGOST HD necessary to capture the ‘melting’phenomenon

fluorescence-only data from log at left

2011 North American Environmental Field Conference and Exposition 26

DYE-LIF bucket tests

• DNAPL loaded onto moist Fisher Scientific sea sand

• ~1 inch thick sand ‘disks’ of DNAPL/sand • wrapped in thin aluminum foil that was

readily punched through but allows any sloughing as if no container existed

2 bucket experiments:• single disk – PCE at 50% pore saturation• stacked 3 disks – TCE at 35%, 17, and 9%

saturation – 1 inch between the 3 disks

2011 North American Environmental Field Conference and Exposition 27

DYE-LIF bucket test logssingle PCE/sand disk buried in bucket of sand 3 TCE/sand disks buried in bucket of sand

2011 North American Environmental Field Conference and Exposition 28

DYE-LIF ‘selectivity’

• some dyes solvate readly in chlorinateds, not petroleum, and vice versa

• solubility of dyes varies with organic solvent

• should allow for tailoring for a selective response

TCE

PCE

clean soil

gasoline

kerosene

2011 North American Environmental Field Conference and Exposition 29

NNLS fitting to ‘find the dye’vs. natural and manmade fluorophores

dye waveforms will often differ from tar, creosote, or oil waveforms

2011 North American Environmental Field Conference and Exposition 30

NNLS fitting to ‘find the dye’vs. natural and manmade fluorophorescontaminants now in digitally separate data sets… can be combined, parsed, visualized

process can be implemented in real time for field discernment between chlorinated DNAPL, PAHs, etc.

chlorinateds

PAHs

2011 North American Environmental Field Conference and Exposition 31

Some questions to ponder:Q: say goodbye to Geoprobe® MIP?A: hardly… as is the case with traditional LIF, DYE-LIF will respond only to

source term NAPL – it won’t ‘follow the scent trail’ like MIP can. DYE-LIF will be brought in to characterize/confirm DNAPL in high probability zones

Q: Will we finally find those needles in the haystack?A: Yes… if they exist. Some claim that most DNAPL ganglia dissolved years

ago and now it’s only back-diffusion that’s providing the high dissolved phase concentrations. I guess we’re fixing to find out!

Q: When will it be commercialized?A: Available early 2011 for select test sites. ESTCP-funded testing at AF sites

from 2011-2013 teamed with AMEC Geomatrix and Guelph University. Likely to undergo a transition from a Dakota service to productization much like UVOST.

Q: How do you plan to “prove” that the DYE-LIF works?A: Good question. Would like to get feedback/ideas!

2011 North American Environmental Field Conference and Exposition 32

Thank you!

Randy St. Germain, President

stgermain@dakotatechnologies.comDakota Technologies, Inc.

2201-A 12th St. N.Fargo, ND 58102

Phone: 701-237-4908www.dakotatechnologies.com