The purposes of this plan were to visit the 152 classified C and D illegal dumping sites listed by the ROC EPA, and to select the most possible contaminated groundwater 30 sites from 152 sites to carry the groundwater pollution survey, and then offered the basis for environmental officials to take follow-up control or emergency response measures in the future. After visited the 152 classified C and D illegal dumping sites, and based on the reply data from the related local Environmental Protection Bureau, it showed that there were no more clean-up actives carried out in 2004 and the situation were still the same as 2004. At the primary stage of this project, there were 15 standard groundwater monitoring wells were installed on the downstream of these sites screened by the last project and examined the groundwater quality. The examined result showed that 14 sites complied with the Taiwan Groundwater Pollution Control Standard, and only in one site, named “the opposite area of Pingtung Country Gausu Hsiang Pu-Qiang-Lun sector land number 323-6 (T008EPA0048)”, discovered the groundwater contaminants. Besides, another 15 possible groundwater contaminated sites were selected to be installed 3 simple wells of each site, and examined the groundwater quality. Based on the examined results of these simple wells, only the total phenols and chromium concentrations in groundwater at the Tainan County Hou-Pi Hsiang Xin-Dong Village No. 148-20 Site (R018EPA0175) exceed the Taiwan Groundwater Pollution Control Standard and the other 14 sites were not. However, there were obvious contaminated evidences founded in the “Changhua County Dacheng Township Shang-Feng Sector land No. 577 and land No. 578 Site (N009EPA0013)”, “Yunlin County Dapi Township Beigang River Lu-Liao Dike Site (P008EPA0152)”, and “Tainan County Guanmiao Township Shen-keng-Zi Sector land No.707-1 Site (R016EPA0126)”. From the preliminary groundwater survey, five sites with contaminated evidences were enforced into the second phase investigation. Another 15 standard groundwater monitoring wells were installed and examined. Based on the examined results of these monitoring wells, the total phenols, chromium and arsenic concentrations in groundwater at Tainan County Hou-Pi Hsiang Xin-Dong Village No. 148-20 Site (R018EPA0175) exceed the Taiwan Groundwater Pollution Control Standard and the groundwater of the other 4 sites showed contamination but complied with the standard. To investigate the groundwater pollutants source of Tainan County Hou-Pi Hsiang Xin-Dong Village No. 148-20 Site (R018EPA0175), the investigation of relationship between the buried waste and the groundwater pollutants were carried. The investigation of relationship results showed that the groundwater pollution was related with the buried waste, and the waste contained the hazardous heavy metal. The Hazardous Ranking System was applied to re-score the site, and the site’s score up to 53.9. Finally, all results of the plan were updated into the Information Management System for Soil and Groundwater Contaminated Sites established by the ROC Soil and Groundwater Pollution Remediation Fund.

Groundwater pollution, site investigation, illegal dumping site