Characterization and source identification of hydrocarbons in water samples using multiple analytical techniques.

Area of Science:

• Environmental Science
• Analytical Chemistry
• Hydrogeology

Background:

• Groundwater contamination poses risks to drinking water supplies.
• Identifying sources and extent of volatile organic compounds (VOCs) is crucial for remediation.
• Bedrock aquifers are vital sources of drinking water, making contamination assessment critical.

Purpose of the Study:

• To identify and characterize petroleum hydrocarbons and VOCs in a drinking water bedrock aquifer.
• To assess the degree of contamination at different depths.
• To determine the implications of contamination for potentially responsible parties.

Main Methods:

• Utilized gas chromatography-mass spectrometry (GC-MS) and capillary GC with flame-ionization detection.
• Employed solid-phase microextraction and headspace GC-MS techniques for sample analysis.
• Analyzed groundwater samples from near-surface and deeper zones of the aquifer.

Main Results:

• Near-surface groundwater (0-5 m) contained gasoline and heavy petroleum products, with total petroleum hydrocarbons (TPHs) at 1070 µg/kg and BTEX at 155 µg/kg.
• Deeper groundwater (15-60 m) showed contamination, with TPHs at 130 µg/kg and BTEX at 2.6 µg/kg.
• Volatile chlorinated compounds were also detected in the groundwater samples.

Conclusions:

• The bedrock aquifer is contaminated with multiple petroleum products and volatile chlorinated compounds.
• Contamination levels decrease with depth, but significant pollution is present even in deeper zones.
• Analytical techniques effectively identified and quantified contaminants, aiding in source assessment.