On November 25, a stationary training of the Polish Association of Developers took place in Warsaw, co-organized by APP-Projekt. We raised the topic: "Contamination and remediation of the plot, the more you know - the less you pay" emphasizing the importance of land research and remediation for the investor's activity in a given area. We discussed, among others the issue of what to pay attention to while writing a remediation plan, waste transportation costs, as well as we presented an interesting case study of ex-situ remediation. The training was attended by many representatives of PZFD member companies.