This project focuses on investigation the four sites declared contamination by Taoyuan authorities including (1) Zhongli Industrial Park A Site, (2) Youth Industrial Park B Site, (3)Youth Industrial Park C site, and (4) Pingzhen District D site. A total of sixteen new monitoring wells were established, and completed volatile organic compounds (VOCs) analysis of twenty-eight groundwater samples and fourteen soil samples, and twenty-six groundwater samples were conducted the compound specific isotope analysis (CSIA). The investigation results indicated that highly contaminated groundwater on these four sites and the contaminated ranges were clearly identified, however, no sufficient information to identify the pollution sources yet. As the result, it shall declare these four sites as the use of groundwater restriction region, and the following detailed investigation should make effort on clarify the range of low concentration contamination (groundwater pollution control standard) and track the pollution sources. Two wells, CL10303 and CL10403 were located in hotspot of Zhongli Industrial Park A Site with TCE concentration over 16 mg/L, and the pollution diffused forward to northeast. In the Youth Industrial Park monitoring B Site, the groundwater plume has diffused and distributed to outside industrial park area among most previous filling up pond, and the TCE concentration in the hot spot has decreased to 0.376 mg/L. Near the C site area, the TCE concentration has increased up to 14.8 mg/L; meanwhile, the dichloromethane (DCM) concentration has reached to groundwater pollution control standard, and two factories nearby C site has been used DCM with the document record. Two TCE polluted plumes were identified at Pingzhen District D site, one in northern region and the other in southern region, According to the CISA results, the pollution source among these two plumes are different, and the plume in southern region is not affecting by the plume in north region. This project collected the numbers of chlorinated ethenes contaminated sites in Taiwan and the current usage of chlorinated solvents statistic data information. It revealed that Taoyuan city still has the largest numbers of chlorinated ethenes contaminated sites in Taiwan, more than one fifth of total numbers. The status reviews of chlorinated contaminated factories and red light industrial parks are completed, and the related management strategies suggestion are provided for the Department of Environmental Protection, Taoyuan to make policies decisions.

Compound Specific Isotope Analysis ,CSIA, Chlorinated solvent, Groundwater contaminated sites