Forensic identification and quantification of oil sands-based bitumen released into a complex sediment environment

Area of Science:

• Environmental Chemistry
• Petroleum Geochemistry
• Forensic Science

Background:

• A significant release of diluted bitumen (dilbit) occurred in the Kalamazoo River in 2010.
• The spilled oil altered its properties, migrating into riverbed sediments.
• Accurate quantification of the spilled oil was crucial for remediation and liability assessment.

Purpose of the Study:

• To develop and apply a method for accurately identifying and quantifying spilled dilbit in environmental samples.
• To distinguish the spilled oil from background hydrocarbons in river sediments.
• To validate the effectiveness of advanced hydrocarbon fingerprinting techniques.

Main Methods:

• Multi-tiered application of advanced hydrocarbon fingerprinting.
• Analysis of key chemical characteristics of the spilled oil.
• Evaluation of concentration ratios of tri-aromatic steranes and triterpanes as biomarkers.
• Validation with field sample results.

Main Results:

• Key chemical characteristics were identified to differentiate dilbit from background contamination.
• Concentration ratios of specific tri-aromatic steranes and triterpanes proved most effective for quantification.
• The developed quantification approach was successfully applied and validated using field data.

Conclusions:

• Advanced hydrocarbon fingerprinting, particularly using biomarker ratios, is a reliable method for quantifying oil spills in complex environmental matrices.
• The environmental stability of petroleum biomarkers supports their use in forensic investigations.
• This methodology aids in environmental remediation and liability allocation following oil spills.