In Bettwiesen, Canton of Thurgonia, waste from a galvanising plant was deposited in a pit in the 1950s - 1970s. The landfill is listed in the cadastre of contaminated sites and hosts locally high levels of heavy metal contamination that can affect groundwater and surface waters. For several years, the site has therefore been investigated and monitored in terms of contaminated sites legislation. Grundbauberatung-Geoconsulting AG has been commissioned to close any remaining knowledge gaps about the spatial distribution of pollutants by executing additional investigations (excavator slots, sampling) and, based on this, to examine and specify existing approaches for the remediation of this site. The investigation thus provides the basis for a subsequent remediation project.