High-fidelity simulation of coupled thermal and groundwater flow around buried objects is critical for predicting thermal infrared signatures, yet it presents a significant computational challenge. To overcome this bottleneck, this work implements the Shifted Boundary Method (SBM), a robust embedded boundary technique [1], within the Adaptive Hydraulics (AdH) code [2]. We present a novel extension of the SBM to solve the coupled physics of thermal transport and variably saturated groundwater flow, governed by the Richards' equation [3]. While SBM has been successfully applied to general convection-diffusion problems, this work represents its first application to the specific numerical challenges posed by Richards' equation, including the handling of steep saturation fronts. Additionally, we address optimal surrogate boundary placement to minimize discretization error for the tetrahedral meshes used in this study. To validate this new implementation, we simulate the coupled thermal-hydrologic response of a buried object using carefully defined initial conditions and compare predicted temperature and saturation profiles directly against a traditional, high-fidelity body-fitted mesh solution. The analysis demonstrates that the SBM achieves a comparable level of accuracy, capturing the key physical interactions that govern the object’s thermal signature. This validated, high-fidelity approach dramatically reduces computational overhead and, most significantly, enables a fully scripted and automated simulation workflow. This method will significantly improve the computational efficiency of extensive parameterization studies involving the variation of a buried object's location and orientation within a soil body. REFERENCES [1] A. Main, G. Scovazzi. The shifted boundary method for embedded domain computations. Part I: Poisson and Stokes problems. Journal of Computational Physics, Vol. 372, pp. 972-995, 2018. [2] R. Berger, S. Howington. Discrete Fluxes and Mass Balance in Finite Elements ASCE Journal of Hydraulic Engineering, Vol. 128, pp. 87-92, 2002. [3] M. Farthing, F. Ogden. Numerical Solution of Richards' Equation: A Review of Advances and Challenges. Soil Science Society of America Journal, Vol. 81, pp. 1257-1269, 2017.