The former Preco site is a historical, metal manufacturing property located in the City of Commerce, California, which has been deemed as an area with significant environmental contamination by the Los Angeles Regional Water Quality Control Board (LARWQCB). Due to the presence of trichloroethylene (TCE), tetrachloroethylene (PCE), and 1,4-Dioxane in groundwater, these residual chlorinated solvents are hazardous to the environment and human health. Previous remediation efforts, like Soil Vapor Extraction, were unsuccessful to address shallow groundwater contamination and the source of the plume. Therefore, alternative remediation efforts have to be explored to achieve long-term water quality stability. This project aims to develop a comprehensive site model and a remedial action plan (RAP) to mitigate contamination and present a solution to LARWQCB. Our team proposes the use of PlumeStop®, an in-situ activated carbon technology provided by Regenesis, to immobilize and treat the residual solvent plume successfully. This approach offers a cost-efficient and long-term sustainable alternative to conventional pump-and-treat methods. This research provides a strategic framework for long-term remediation and environmental restoration to combat antecedent contamination.