Uncertainty analysis of physical parameters present in the groundwater model is important from the point of safety measures in the field of nuclear science and technology. Researchers have carried out this uncertainty analysis using traditional Monte Carlo simulations. However, in practice, Monte Carlo simulation may not be possible because of lack of data obtained from field experiments. Therefore, the demand is to investigate uncertainty using imprecise-based method. In order to fulfill this demand, we have carried out uncertainty analysis of groundwater model parameter using fuzzy set and hybrid methods. Monte Carlo-based uncertainty is also presented in this paper. Overall, this paper highlights the various methodologies of uncertainty analysis. In the hybrid approach, the concept of fuzzy random variable and its computational details have been explored. Retardation factor is our representative groundwater model parameter on which illustration of the said methodologies of uncertainty modeling is presented.