Presentation on the use of petroleum biomarkers for delineation of petroleum impacts in a high organic soil area (muskeg). Phytogenic hydrocarbons are natural compounds that are misidentified by standard analytical methodologies of high organic content soils as petroleum hydrocrabons. This artificially biases the measurements high for organic rich soils. Petroleum hydrocarbon products have distinct petrogenic biomarkers that can be used to identify if a sample contains petroleum or not. These biomarkers were used in this presentation to determine where petroleum impacts in the soil end and limit the unnecessary excavation of a muskeg chasing samples that were above guidelines due to the presence of natural hydrocarbons. Presentation shows how environmental forensics and petroleum forensics investigations can be used in an environmental site assessment.