The intern will work on quantifying inherent uncertainties associated with natural attenuation of organic contaminants at upstream oil and gas contaminated sites. Uncertainty and variability in parameters such as hydraulic conductivity, biodegradation rate constant and spatial distribution of the source of contaminants may lead to highly uncertain results to be obtained from routine fate and transport models. Thus, there is a need to quantify these uncertainties and study their impact on the predicted plume size and clean up time. During his internship period, the intern will have the opportunity to gain insight into practical issues associated with his modeling work, including practical determination of parameters required in bounding the problem, considering their spatial and temporal variability.