Geoenvironmental engineering addresses the interaction between geological, environmental, and engineering factors to mitigate environmental risks and protect human health. Develop a theoretical framework elucidating the principles of geoenvironmental engineering, including contaminant transport, fate and remediation, and groundwater flow modeling. Discuss theoretical models for assessing the impacts of contamination on soil and groundwater quality, such as fate and transport modeling and risk assessment methodologies. Explore theoretical approaches to designing and implementing remediation strategies, including in$-$situ and ex$-$situ treatment technologies, and analyze their effectiveness in restoring environmental quality and mitigating human health risks.