This project achieved a number of objectives regarding investigation of groundwater and soil contamination, verification of regulated sites, maintenance and management of groundwater monitoring wells in Yilan County. Whilst the project duration was started from 1/1/2014 to 31/12/2014, the major achievements are stated as follows: 1. Re-investigation of 4 high pollution potential sites locating at Yilan City and Dongshan Township was accomplished. In total, 10 sampling points of controlled heavy metal (HM) and 8 sampling points of X-Ray fluorescence analysis in soil were conducted, and 1 groundwater monitoring well was analyzed for general items and volatile organic compounds (VOCs). One site in Dongshan Township was found high concentration of Arsenic in soil, in view of this region is affected by natural geochemical characteristics of As-polluted groundwater and sediments, a sustained monitoring of groundwater and soil is recommend ; another site in Dongshan Township was found copper concentration in soil exceeded Standard Monitoring Levels. 2. Extensive investigation related to fecal-source HM contamination of farmland was complete after performing 140 sampling points of X-Ray fluorescence analysis, 30 sampling points of soil texture, 70 sampling points of controlled HM in soil, and 10 groundwater wells analysis for general items and heavy metal. In conclusion, Yilan County could be divided into 3 areas with different risk levels of fecal-source HM contamination. The highest area was located in Datong Township(upper reaches of Lanyang river) where long-term and high-frequency fertilization of abundant feces from livestock and poultry significantly dominated the accumulation of HM with farmland. Nevertheless, a current phenomenon was observed that farmers in Datong Township tend to deepen plowing depth which led to the decline of detected HM accumulation. 3. Environmental impact assessment of surrounding area of Lize Incineration Plant was accomplished through establish an ISC-ST3 model (Industrial Source Complex Short-Term Mode) and rank the dust-fall quantity of different area. The model was applied to arrange 60 sampling points of X-Ray fluorescence analysis, 20 sampling points of controlled HM in soil, and 6 sampling points of dioxin analysis. The result had shown scarcely accumulation of HM and dioxin in the soil, hence a further investigation specifically aimed at plants was suggested. 4. The maintenance, management and monitoring of groundwater wells including accomplish 49 groundwater monitoring wells’ sampling for general items and the HM, construct 3 standard monitoring wells, implement slug test analysis and well development. 5. The emergency sampling and investigation during the process of this project including 18 investigation cases. Site locations include Dongshan Township, Su’ao Township, Sanxing Township, Zhuangwei Township, Yuanshan Township, Jiaoxi Township and Wujie Township