This project is the Phase II Expansion Project of a hazardous waste landfill site in Shanghai. The EIA report focused on the feasibility of groundwater pollution prevention measures and the Class 1 impact assessment on the groundwater environment. The innovation of this report was embedded in its contents: comprehensive management measures recommended to prevent groundwater pollution; corresponding emergency response plans; improvements to the groundwater monitoring system; monitoring of leachate discharge, allowing potential leakage to be promptly detected.