Alberta Peatlands

=

False PHC detections in peat soils

surrounding an oil spill

2016 RemTech Conference, Banff Alberta

Biogenic Interference Calculation (BIC) Index for Resolving False Exceedences of AB Tier-1 F3 PHC Soil Guidelines Due to Biogenic Interferences in Peat Soils

Francine Kelly-Hooper, PhD, Soils Scientist

CH2M HILL Canada

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What is the BIC Index?

Pronounced “BIC” like the pen

� Calculation for determining if biogenic interferences have caused organic (peat) samples to falsely exceed the Alberta Tier-1, 300 mg/kg F3 PHC soil guideline.

� [F2/(F2+F3b)] x 100

� <10% = false PHC exceedence

� >10% = true PHC exceedence

BIC Index Continues to Evolve After 14 Years of Research

2004

2016

Continuing method development

2004 - 2016 Research Partners

Imperial OilALS Laboratory Group

Canadian Association of

Petroleum Producers

Husky EnergyAlberta Parks and Protected

Areas Division

Environment Canada Oil

Spills Research Centre

Orphan Well Association

Canadian Geological Survey

Petroleum Technology Alliance of

Canada

(Village that Raised the BIC Index)

Natural Sciences and Engineering

Research Council

University of Waterloo

STUDY OBJECTIVES Comparison of Control Experiment Data to Field Validation Data

To determine if the BIC Index will correctly identify samples that have

or have not falsely exceeded the most stringent Alberta Tier 1 F3 PHC

soil guideline (300 mg/kg) in all clean and contaminated soil samples

Controlled Training Data Sources

Data Set #1: 300-Day Crude Oil Spiked Peat PhD Experiment

Clean peat and sand were spiked with crude oil and studied for biogenic vs petrogenic carbon distributions over time.

Data Set #2: 300-Day Diesel Spiked Manure PhD Experiment

Compost and sand were spiked with diesel drilling invert and studied for biogenic vs petrogenic carbon distributions over time.

Field Validation Data Sources

Data Set #3: Background PHC survey of 34 sites located in Alberta, BC and Newfoundland

� Canadian Geological Survey collected 34 background soil samples for the biogenic vs petrogenic carbon distribution study

Data Set #4: Orphan Well Association Field Validation Site

� The OWA collected 55 samples from a 35-year old crude oil contaminated Alberta peatland for the biogenic vs petrogenic carbon distribution study.

What are biogenic organic compounds (BOCs)?

� BOCs are carbon-based compounds, which are naturally biosynthesized by living organisms.

� BOC groups containing C, H and O include: lipids, carbohydrates, proteins and nucleic acids.

� BOC hydrocarbon groups containing only C and H include n-alkanes.

Canadian Council of Ministers of the Environment (CCME)

Reference Method for the Canada-Wide Standard (CWS) for

Petroleum Hydrocarbons (PHC) in Soil

Methods can produce false positives in uncontaminated organic materials (e.g. peat, manure, etc.).

The goal is to “capture” petroleum hydrocarbons.

However, background biogenic organic

compounds are inadvertently “captured” as well.

The problem is that the hexane and acetone solvents indiscriminately

extract all carbon from petroleum and biological sources.

Extract

injection

F2, F3, F4

concentrations

quantified by

chromatogram

integrations

) ) ) ) ) ) ) )ion flowflame detector

capillary column

carrier

gas

line

Vaporizer

Oven

Flame Ionization

Detector

electronic

signal

GC-FID Analysis of Sample Extract

Retention Time (minutes)

0

100

200

300

pA

4 5 6 7 8 9 10 11

F4

>C34

F3

C16-C34

F2

C10-C16

UCM

Diesel

F3 2000 mg/kg

Reported F33000 mg/kg Peat

F3 1000 mg/kg

Diesel-Spiked Peat GC-FID Chromatogram

Carbon Numbers

F1 F2 F4

C10 C16C6 C34 >C34

F4C34

F1 F2C10-C16

>

F3C16-C34C6-C10

Biogenic Organic Compounds

(e.g. fatty acids, sterols, waxes, etc. )

Gasoline

Diesel/No. 2 Fuel Oil

Crude Oil

No. 6 Oil/Lube Oil/Heavy fuels, Tar, Asphalts

Classification of Petroleum Hydrocarbon Sources by Carbon Number Range

Comparison of Background Soil Survey Results to

Alberta Tier-1 Soil and Groundwater Remediation Guidelines

Alberta Tier-1 Soil Remediation Guidelines

“Coarse textured soil remediation

guidelines may be used for organic

contaminants in organic soils”

34 Background Soil Samples: Alberta, BC, Newfoundland

0

400

800

1200

1600

F3 (

mg

/kg

)Comparisons of F2, F3, F4 Concentrations to AB Tier-1 Soil Remediation Guidelines

Surface Soils Natural/Agricultural/Residential/Parkland Guidelines

16 samples (47%) exceeded

F3 coarse soil standard300 mg/kg

0

50

100

150

200

F2 (

mg

/kg

)

0 samples exceeded

F2 course soil standards150 mg/kg

%TOC

0

1000

2000

3000

0% 10% 20% 30% 40%

F4 (

mg

/kg

)

0 samples exceeded F4

course soil standards

2800 mg/kg

0

400

800

1200

1600

F3 (

mg

/kg

)

16 samples (47%) exceeded

F3 coarse soil standard300 mg/kg

0

50

100

150

200

F2 (

mg

/kg

)

0 samples exceeded

F2 course soil standards150 mg/kg

34 Background Soil Samples: Alberta, BC, NewfoundlandComparisons of F2, F3, F4 Concentrations to AB Tier 1 Soil Remediation Guidelines

Surface Soils Natural/Agricultural/Residential/Parkland Guidelines

Only F3 exceeded the guideline

• All soils with >28% TOC exceeded the F3 coarse soil standards

• Peat soils have >40% TOC

source: Alberta Geological Survey

Peat soils cover 18% of Alberta

But there is a light at the end of the tunnel!

Biogenic Interference Calculation for Identifying False Exceedences of the AB Tier-1, F3 PHC 300 mg/kg Soil Guideline

Formula

F2 = measured F2 (C10-C16) concentration

[F2/(F2+F3b)] x 100

F3b = measured F3b (C22-C34) concentration

Index Values

<10% indicates that BOCs have caused false exceedences of F3 PHC guideline

>10% indicates true exceedences of the F3 PHC guideline

Non-detectable F2

Detectable F2

Detectable F2

F3a (C16-C22) and F3b (C22-C34) Distributions in Diesel and Clean Peat

F3a

F2 Total F3 F4

Carbon NumberC16C10 C22 C34

Clean Peat

7% F3a93% F3b

11% F3b

89% F3a

F3b

63%

F3a

37%

Diesel

Diesel Contaminated

Peat

F3b(C16-C22) (C22-C34)

Non-detectable F2

Detectable F2

Detectable F2

F3a (C16-C22) and F3b (C22-C34) Distributions in Crude Oil and Clean Peat

F2 Total F3 F4

Crude + Peat

Carbon Number

C16C10 C22 C34

Peat

69% F3b

31% F3a

F3a F3b(C16-C22) (C22-C34)

FederatedCrude Oil

50% F3b

50% F3a

7% F3a 93%

F3b

13 Crude Oil Samples

% o

f T

ota

l F

3 C

on

cen

trati

on

0

25

50

75

100

13 Fresh Crude Oil Samples 34 Background Soil Samples

34 Soil Samples

0

25

50

75

100

% o

f T

ota

l F

3 C

on

cen

trati

on

F3a (C16-C22) F3b (C23-C34)F3a (C16-C22) F3b (C23-C34)

Median

F3b 93%

F3a 7%F3b 51%

F3a 49%

Median

1 2 3 4 5 6 7 8 9 10 11 12 13

F2, F3, F4, F3a, F3b Carbon Distributions in PHC Products and Clean Peat

F3a F3b

F2 F3 F4

Tar

Engine Oil

Crude Oil

Diesel Fuel

Peat 7% F3a 93%

F3b

F3a 89%

F3b 11%

53% F3b

47% F3a

6% F3a

94% F3b

14% F3a

86% F3b

High F3a

High F3a

Low F3a

Low F3a

Low F3a

Carbon NumberC16C10 C22 C34

Clean Peat

Diesel

Diesel Spiked

Peat

69%

33%

F2

F2 = 823 mg/kg

F3b = 371 mg/kg

F2 = 613 mg/kg F3b = 2,816 mg/kg

F2 = 10 mg/kg F3b = 1,395 mg/kg

F3b

= Guideline Exceedence

[F2/F2+F3b] x 100

1% = Guideline not

Exceeded

= Guideline Exceedence

Example of BIC Index for Diesel PHCs

Total F3

F2

Total F3

Carbon NumberC16C10 C22 C34

Clean Peat

F2 = 10 mg/kg

F3b = 1,000 mg/kg

1%

Crude Oil Spiked

Peat

F2 = 1,000 mg/kg

F3b = 2,000 mg/kg 33%

F3b

Crude Oil

F2 = 1,000 mg/kg

F3b = 1,200 mg/kg

45%

= Guideline not Exceeded

= Guideline Exceeded

= Guideline Exceeded

[F2/F2+F3b] x 100

Example of BIC Index for Crude Oil PHCs

No Yes

Does the GC-FID chromatogram image have an obvious

Unresolved Complex Mixture (UCM) petrogenic pattern?

No

Heavy PHCs may be present

(Do not proceed with the evaluatio)

Indicates false exceedance

of F3 PHC guideline

BIC Index Decision Tree for Identifying False Exceedences of AB Tier-1 F3 PHC 300 mg/kg Soil Guideline

Indicates true exceedance

of F3 PHC guideline

Is the Biogenic Interference Calculation >10%?

Yes

Pre-screening criteria: only include samples that meet these criteria

1) F2 concentration is less than laboratory method detection limit (<20 mg/kg)

2) F3 concentration exceeds the 300 mg/kg guideline, F4 concentration does not exceed any guidelines

3) The released PHC product(s) must extend into the light F2 (C10-C16) carbon range (e.g. diesel, crude oil, etc.)

4) A qualified person must confirm that the GC-FID chromatogram does not have a heavy PHC pattern (e.g. asphalt, bitumen, motor oil, etc.).

Bio

gen

ic In

terf

ere

nce

Calc

ula

tio

n

> 10% indicates true F3 PHC

guideline exceedences

<10% indicates false F3 PHC

guideline exceedences

Peat spiked with crude oil;

compost spiked with diesel invert Clean soils and compost

BIC Index Testing of Control Samples: Clean and Spiked Soil and Compost

Bio

gen

ic In

terf

ere

nce

Calc

ula

tio

n

> 10% indicates true F3 PHC

guideline exceedences

<10% indicates false F3 PHC

guideline exceedences

Peat spiked with crude oil;

compost spiked with diesel invert Clean soils and compost

• BIC Index correctly identified true F3 PHC guideline exceedences in all crude

oil and diesel spiked samples

• BIC Index correctly identified false F3 PHC guideline exceedences in all

clean samples

BIC Index Testing of Control Samples: Clean and Spiked Soil and Compost

Bio

gen

ic In

terf

ere

nce

Calc

ula

tio

nField Validations of 37 Year Old OWA Crude Oil Contaminated Peatland

Peat samples with detectable F2 and

>300 mg/kg F3 concentrations

Peat samples with non-detectable F2 and

>300 mg/kg F3 concentrations

> 10% indicates true F3 PHC

guideline exceedences

<10% indicates false F3 PHC

guideline exceedences

Bio

gen

ic In

terf

ere

nce

Calc

ula

tio

nField Validations of 37 Year Old OWA Crude Oil Contaminated Peatland

Peat samples with detectable F2 and

>300 mg/kg F3 concentrations

Peat samples with non-detectable F2 and

>300 mg/kg F3 concentrations

> 10% indicates true F3 PHC

guideline exceedences

<10% indicates false F3 PHC

guideline exceedences

• All samples with >300 mg/kg F3 and non-detectable F2 concentrations

were identified as false PHC guideline exceedences

• All samples with >300 mg/kg F3 and detectable F2 concentrations were

identified as true PHC guideline exceedences

BIC Index Statistical Probability Test Results

The BIC Index is a highly conservative/cautious tool.

0% probability of missing true exceedences.

10% probability of missing false exceedences.

Next Steps?

� CH2M is currently expanding the BIC Index to include heavy PHCs

(e.g. asphalt, bitumen, motor oil, etc.) as well.

Francine Kelly-Hooper

f.kellyhooper@ch2m.com

519-502-3122