This lecture covers the environmental legislation related to construction and soil protection, focusing on contaminated sites and the legal obligations of companies. It discusses a case study involving a landfill site that led to water pollution, emphasizing the need for soil remediation. The lecture also explores the importance of protecting soil fertility and the regulations governing soil pollution by heavy metals. It delves into the strategies for soil protection in Switzerland, the pollution of agricultural soils by copper and zinc, and the measures for soil protection and remediation. Additionally, it addresses the distinction between soil protection and site management regulations, providing recommendations for preventing soil pollution and ensuring public health.