A preliminary assessment and site investigation (PA/SI) of the Olivette Mine was performed to determine the presence of hazardous substances and whether they pose a risk to human and ecological health.

A PA/SI is the first step in the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) process of determining whether a site poses a risk to human health or the environment. A preliminary assessment compromises of gathering historical data about site conditions to evaluate whether the site poses a risk and whether further investigation is needed. A site investigation involves testing air, water, and/or soil at the site to determine if hazardous substances are present, whether or not they are being released into the environment, and if they pose a risk to human or environmental health.

A site investigation was conducted to collect soil samples for laboratory analysis of heavy metals, survey flora and fauna, and gain a better understanding of the mechanisms by which offsite contaminant migration may occur. The information gathered from the site investigation and laboratory analysis were used to perform a quantitative human health risk assessment and qualitative ecological risk assessment. Lastly, contaminant migration pathways were assessed to determine if contaminants are migrating offsite.