Brent Pautler SiREM

Waterloo Membrane Sampler: Passive Sampling in Remediation Projects; Soil Gas, Outdoor Air and Implications for Vapor Intrusion Studies

www.vertexenvironmental.ca

SMART RemediationO awa, ON │ February 6, 2020

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Waterloo Membrane Sampler: Passive Sampling in Remediation Projects; Soil

Gas, Outdoor Air and Implications for Vapor Intrusion Studies

Brent G. Pautler, Ph.D.

February 6, 2020

Hester Groenevelt, M.Sc.; Todd A. McAlary, Ph.D.

Geosyntec Consultants

Matthew Edwards, Ph.D.

SepSolve Analytical

Robert M. Healy, Ph.D.

Ontario Ministry of the Environment,

Conservation and Parks

Introduction to SiREM

• Founded in 2002

• Located in University of Guelph Research Park

• Provide products and testing services to support and improve site remediation

• Further information:www.siremlab.com

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SiREM Service Areas

Bioaugmentation

Characterization/MonitoringRemediation Testing Molecular Genetic Testing

Passive Sampling

Benefits of Passive Sampling

• Quick & easy protocols• Cost effective vs. active sampling

• Labor & shipping

• Unobtrusive installation & retrieval• Time-integrated sampling

• Adjustable sensitivity

• Minimizes sampling variability

• Quantitative results

• Broad range of compounds • VOCs, SVOCs, PAHs, etc.

• Most soil & moisture conditions• No electricity, mechanical parts, connections or calibrations

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What’s wrong with Conventional Samples?

Canisters / TO-15► Bulky (expensive to ship)

► Expensive to replace

► Subject to potential leaks

► Not well suited to long sample duration

► Looks like a “bomb”

Active Sorbent Tubes / TO-17

► Not well suited to long sample duration (breakthrough)

► Power requirements

► Pump calibration

Shipping and Handling

72 Summa canisters 72 passive samplers

Key Point: passive samplers are much easier to work with

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Passive Sampling

tUR

MC

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The mass (M) and time (t) are measured accurately. The key is to know the uptake rate (UR).

UR has units of mL/min

For Kinetic Samplers

What about Acute Risks?

Ontario’s Ambient Air Quality Criteria:Trichloroethene (TCE):

Annual = 2 μg/m3

24-hr = 12 μg/m3

Consider a 10-day passive sample with TCE = 1.0 μg/m3 or less

No single 24-hr day could have had TCE >10 μg/m3 – therefore, no risk!

https://www.ontario.ca/page/ontarios-ambient-air-quality-criteria-sorted-contaminant-name

tUR

MC

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3M OVM 3500

Differences: size, uptake rates, sorbents, medium of uptake, method of analysis

ATD Tubes SKC Ultra3 Waterloo Membrane Sampler

Radiello

Passive Sampling Options

The Waterloo Membrane SamplerTM (WMSTM)

Sorbent

polydimethylsiloxane(PDMS) membrane

Crimp cap

Glass vial

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WMSTM Fine-Tuning Options

Opening SizeMembrane Thickness Sorbent options

Tune the sampler to high or low concentrations, short or long durations

WMSTM APPLICATIONS

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Quantitative Passive Soil Vapour Sampling

Soil Gas Sampling

Increase membrane thickness to reduce the uptake rate

Microscope photo of cross‐section of PDMS membrane

Thick membrane sampler plus duplicate being deployed in a soil gas probe

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Semi-Quantitative Passive Sampling

Amplified Geochemical Imaging® Survey (Formerly the Gore Module

or GoreSorber)

Petrex Tube (Petroleum Exploration)

Beacon Be-Sure™

Key Point:Uptake rates are not quantified or controlled

Comparison: Semi-quantitative vs. QuantitativeGore Module Waterloo Membrane Sampler

http://events.awma.org/education/Posters/Final/Whetzel_Poster.pdf https://serdp‐estcp.org/Program‐Areas/Environmental‐Restoration/Contaminated‐Groundwater/Emerging‐Issues/ER‐200830/ER‐200830Whetzel et al., 2010

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Soil Gas Sampling – data presentation

VCcDCE tDCE

PCE TCE

Vapor Intrusion Challenge

Key Point:Passive Sampling manages temporal variability

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Perimeter Fenceline Monitoring (EPA Method 325)

U.S. Federal Register 40 CFR63 – requires all refineries to monitor benzene (June 20 2013)14‐day samples by passive ATD tube (325A) – analysis by TD/GC/MS (325B)

Canada: similar regulations as of 2018https://www.canada.ca/en/environment‐climate‐change/services/sustainable‐development/strategic‐environmental‐assessment/public‐statements/regulations‐release‐volatile‐organic‐compounds.html

https://www.govinfo.gov/content/pkg/FR‐2013‐06‐20/pdf/2013‐14624.pdf

Challenges:  14‐day samples (constrained by retention capacity) – 26 rounds per yearPotential biases from wind, moisture

Outdoor Air Sampling: R&D with the Ontario MECP

• Modified sorbent to be a thermal desorption-strip or cartridge

• Allows for thermal desorption GC-MS analysis (increased sensitivity)

• Thicker membrane for lower uptake

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Outdoor Air Sampling: R&D with the MECP

ATD Tubes with regular cap and low-uptake rate cap

WMS with loose sorbent beads, sorbent packet and sorbent strip

Continuous Real-time Monitoring via AMA GC 5000 series on-line GC-FID by MECPVOCs directly sampled onto a concentrator then sends to a GC column with an FID detector at the column exit.

Outdoor Air Sampling: R&D with the MECP

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0 500 1000 1500 2000

ppb

Hours

Xylenes (3 months)

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ppb

Hours

Ethylbenzene  (3 months)

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ppb

Hours

Toluene  (3 months)

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Hours

Benzene  (3 months)

Outdoor Air Sampling: Continuous Roadside Monitoring

COV = 62%Average = 0.19 ppb

Average = 0.08 ppb

Average = 0.58 ppb

Average = 0.3 ppb

COV = 108%

COV = 115% COV = 112%

COV = Coefficient of Variability= Standard Deviation / Mean

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0.20

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1.00

1 month 2 months 3 months

C/Co

Deployment

Regular ATD Tubes*

Benzene

Toluene

Ethylbenzene

m,p‐xylene

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1 month 2 months 3 months

C/Co

Deployment

WMS‐TM Strip Temp Corr UR

Benzene

Toluene

Ethylbenzene

m,p‐xylene

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1 month 2 months 3 months

C/Co

Deployment

WMS‐TM Cart Temp Corr UR

Benzene

Toluene

Ethylbenzene

m,p‐xylene

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1.20

1 month 2 months 3 months

C/Co

Deployment

Low Flow ATD Tubes

Benzene

Toluene

Ethylbenzene

m,p‐xylene

Outdoor Air Sampling: Passive Samplers

The green line represents a perfect correlation between passive and active samples

4% < COV < 9%3% < COV < 8%

1% < COV < 10%* * Benzene excluded2% < COV < 6%

14 Day Sampling (EPA 325) 

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Summary of WMS™ Benefits

• Ability to predict uptake rate for less common compounds

• Ability to do TPH/GRO

• Minimal effect of moisture (benefit for soil vapor monitoring)

• Insensitive to wind velocity (benefit for outdoor and vent-pipe)

• Ability to modify uptake rate to avoid: – “starvation effect”

– sorbent saturation/poor retention

• Small diameter (easier to put in vent-pipes or sub-slab probes)

• Competitive pricing

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WMS™ Resources

https://www.siremlab.com/remediation‐pathways‐autumn‐2019/http://www.siremlab.com/pages/wms/

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WMS™ Distribution – 2020!

Acknowledgements

Hester GroeneveltTodd McAlary

Jeff RobertsSteve SandeBryce Gordon

Prof. Tadeusz GóreckiFaten SalimOana Goli

Robert Healy

Matt Edwards

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Questions?

WMS

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