Chlorinated solvents are widely used in various industries in Taiwan. Once the solvents leak and spread into the subsurface, the investigation and remediation of these solvents are more difficult than heavy metal and total petroleum hydrocarbons (TPH) contaminants due to their higher mobility in the heterogeneous hydrogeological conditions. The project was the 4th year of continuous project which contained two subsidiary projects (A and B). The following tasks were completed in accordance with the objectives of the project including: conducted the two-stage investigation of soil and groundwater contamination at the chlorinated solvent operating factories selected; assisted the EPA in performing the investigation and verification of contaminations of other potential sites; updated and modified the guidelines of DNAPL investigation issued by the EPA. The final report of this project included the feedbacks of site screening and investigation procedures, in hoping that these will assist the EPA to set up an economical and effective method in processing chlorinated solvent operating cases in the future. With the focus on high potential contaminated facilities using chlorinated solvents, one hundred and three facilities were selected for environmental site assessment phase I and thirty-three priority sites were investigated. The concentration of soil and groundwater contamination of twenty-one sites had exceeded the pollution control standards. The enforcement rate of contamination investigation was 63.6 percent in this project. Out of the nineteen investigated sites in subsidiary project A, there were eleven sites with groundwater or soil contamination concentration exceeding the pollution control standards Out of the fourteen investigated sites in subsidiary project B, there were ten sites with groundwater or soil pollutant concentration exceeding the pollution control standards.

Soil and Groundwater, Chlorinated Solvent, Operating factory;Soil and Groundwater, Chlorinated Solvent, Operating factory