Geotechnical and environmental aspects of the borrow sites are an important part of the project for the construction of the transversal embankment Odra – Suša. It is necessary to ensure the long-term stability of the site after excavation, maintain the functionality of the local ecosystem, and integrate the project into the environment as much as possible to minimize human impact. The introductory section of the theses describes the factors that influenced the selection of the subject site location. All material parameters needed to determine the suitability of materials for embankment construction are explained, along with descriptions of field investigations, laboratory tests, and their analysis. The criteria and relevant technical execution conditions used to determine the material suitability for embankment construction are briefly described. The aspects of the project's impact on the environment are described through effects on individual environmental elements such as water, soil, air quality, waste generation, etc. Detailed assessments and analyses have been conducted for each of these aspects to identify potential negative impacts and define measures for their mitigation or elimination. After the work is completed, the proposed site rehabilitation includes restoring the topsoil layer, planting vegetation, and other activities aimed at reducing the ecological footprint of the project. Numerical analyses were performed using the GeoStudio computer program to assess the stability of the site in different projected scenarios and to potentially determine additional security and stability enhancement measures if necessary. It was concluded that the site consists of high-plasticity and low-plasticity clays, with the highly plastic clays being used for the core of the embankment and the low-plasticity clays for the body of the embankment. The stability of the site is ensured by excavation at a slope of 1:3 without the need for additional geotechnical measures.