The Barreiro site is a former industrial site in Portugal. For many years, industrial waste such as ash from pyrite roasting has been deposited, resulting in a complex mixture of heavy metals in the sediment and groundwater. The investigations focused primarily on arsenic and zinc. The groundwater level was approx. 2.5-3 meters below ground, had a thickness of approx. 35 meters and consisted of medium to fine sand. The groundwater velocity was 0.08-0.10 meters per day. Since no remediation target was defined by the property owner, the target for this demonstration test was to reduce the main pollutant load to 50% of the untreated values.