Hong Kong Kai Tak Airport began decommissioning and decontamination works since 1998, it aims to remove and treat underground volatile organic compounds (VOCs), heavy metals and Total petroleum Hydrocarbon(TPH) at the south apron of the former Kai Tak Airport by using Biopiling and Solidification . During remediation, the contaminated soils should be excavated from the excavation zones and then transported to preferably a centralized decontamination works area on site for treatment by biopiling and solidification / stabilization.