Abstract
The properties of illegally dumped waste and long-term transition of pollutants from that waste were investigated at an illegal dumping site. The investigation results are described as follows. First, the site was excavated during 2003-2004 to remove buried waste. Many waste drums were discovered, in which waste oils such as gasoline, kerosene, engine oil, and coal-tar products remained. These waste oils contained toluene, xylene, tetrachloroethylene (PCE), and trichloroethylene (TCE). These pollutants had also contaminated the excavated soil. Second, a groundwater investigation around the site, conducted during 1990-2004, revealed contamination by volatile organic compounds (VOCs) such as PCE and TCE. Most of the PCE and TCE had degraded to cis-1,2-dichloroethylene. The total molar concentration of the three VOCs in groundwater had decreased since 2000.