Terra Mentis staff worked at the direction of WDEQ as the principal oversight contractors for risk assessment aspects under Wyoming's Voluntary Remediation Program for two RCRA sites associated with the former Refinery. The units consisted of the former Refinery and a large former land disposal area. Risk Assessment activities included: the review of Data Quality Objectives, sampling plans to meet the DQO for human health and ecological risks. Evaluated risk-based exposure areas for a site redevelopment plan and contractor prepared risk assessments. This work included discussions with Chevron/Texaco and WDEQ, the development of sampling and remediation plans for lead and PAH. It also included reviewing contractor completed risk assessments and remediation plans. The resulting work led to improvements and updates to the WDEQ VRP fact sheets.