Based on the “polluter pays principle”, the polluter, potential polluter, have to be identified and asked to take the liability to cover the expense. However, it is very difficult to find out who is the polluter, except for few cases as north of Changhwa County. In most cases the characteristics of heavy metals in soil exhibited complex spatial variations and patterns, and the pollutants came from many sources with a long period of time, caused it very difficult to identify attribution of liability. The remediation of soil pollution in contaminated sites, located in Taoyuan County, Hsinchu City, Miaoli County, Taichung City, Changhwa County, Chiayi County and Pingtung County have been completed through carried out many remediation projects funded by government. The main purpose of this project is to unravel environmental factors at contaminated site using a combination of different approaches, and trying to figure out the liability of irrigation associations as the potential polluter. After collecting and summarizing the related documents in terms of environmental factors, surrounding geological features, the relevant historical investigation records, irrigation system information, and spatiotemporal data, a task-oriented geographic information systems (GIS) database was built. Among the 373 cadastral lots, 326 paddies belong to Taoyuan, Taichung and Changhwa Irrigation Associations. Using the potential pollution index to analysis where are the vulnerable pollution locations, and judge the surrounding irrigation system as the path way to cause the farmland pollution. In general, irrigation has been proved as a major route of pollutants transportation and in consequence of agricultural soil pollution. By the law, the irrigation associations take responsibility in charge of the safety of irrigation water quality and quantity. Obviously, improper management of irrigation system occurred in soil pollution process, and the irrigation associations should take the liability as potential polluter.

Agricultural soil pollution pattern;heavy metals in soil;cost recovery claim