Abstract

Federal and many state regulations governing site remediation of hydrocarbon contamination and site closure require environmental risk assessment activities for developing remediation systems and closure strategies protective of human and ecological populations. Environmental risk assessment activities are normally foreign to many petroleum industry professionals. This article is intended to provide those professionals with sufficient knowledge to achieve environmental risk assessment success.

Classic environmental risk assessment process consists of data collection and evaluation, exposure assessment, toxicity assessment, and risk characterization. These steps ultimately result in identifying what contaminants were released, evaluating which contaminants pose a threat to humans and ecosystems, and quantifying how harmful each of the contaminants are to certain human and ecological populations.

The physicochemical nature of hydrocarbons relevant to remediation is relevant to risk assessment. The facts that most hydrocarbons are not easily miscible in water, volatilize in the presence of air, readily sorb to clays, and are actively bioremediated in the subsurface enable one to avoid risk assessment barriers often encountered with inorganic chemicals. The unique fate of hydrocarbons in the environment should be used by the petroleum professional turned risk assessment/site closure manager to eliminate chemical exposure scenarios based on little more than organic chemistry. This technique allows petroleum industry professionals to use their realm of expertise to familiarize otherwise unknown risk assessment issues.