Locating a construction site in complicated ground conditions requires the use of various solutions. The West Railway Station in Warsaw is located in the area of organic soils, mainly gyttja and peat, reaching a thickness of up to several meters and making it necessary to increase the thickness of the diaphragm wall up to 100 cm. The article describes the geotechnical conditions, typical solutions as well as the necessity to change and limitations related to the presence of organic soils.