The tasks of this project consisted of implementing soil and groundwater pollution investigation and verification for Tao Yuan County, inspecting the contamination of the gas stations within the county, assisting with the soil or groundwater sampling and testing for civil complaint cases, as well as validating the pollution cleanup results for the regulated sites.
Six agricultural site investigations were conducted for soil survey. The soil test results for heavy metals on the agricultural site indicated that copper and zinc had exceeded the regulation limits for farmland soil. The County Environmental Protection Bureau (EPB) has promulgated the lots as regulated pollution sites. The analytical results of eleven regulated soil pollution sites were verified to be in compliance with the regulatory limits and the EPB will remove these sites from the regulated list accordingly. The investigation in 2010 for the five potentially highly polluted gas stations indicated that the total petroleum hydrocarbons in soil were found to exceed the regulatory limits in three gas stations.
The groundwater investigations were conducted for five civil complaint case. The analytical results were found to meet the regulatory limits. A monitoring well was installed in the five regulated pollution sites respectively. However, groundwater samples collected from the simply constructed wells of the two regulated gas stations indicated that benzene and diesel range total petroleum hydrocarbons exceeded the regulatory limits respectively.
Soil vapor well monitoring and cathodic protection tests were performed for 287 gas stations for the project in 2010 to 2011. The results indicated that 44 soil vapor wells in the gas stations were found to be working improperly; 58 soil vapor well examinations and 117 cathodic protection tests had abnormal results.
In addition, the work crew for this project went around and inspected the County-regulated pollution site every other month, repaired sixteen damaged monitoring wells, and reviewed sixteen work plans submitted for the gas stations and twenty-four reports for regulated pollution sites. Two advocacy workshops for gas station workers were also held in October 2010.
The project has assisted the Environmental Protection Bureau (EPB) with supervising the soil and groundwater cleanup for the regulated sites, validation of the ongoing gas station groundwater clean-up, reviewing the reports submitted for the gas stations and regulated pollution sites, and investigating civil complaints. For the future project, we suggest that, regular monitoring of the pollution sites is necessary to comprehend the progress of remediation. Also apply more aggressive technique, like soil gas test, to find out potential contaminated sites and prevent the pollution spread. The GIS database build by EPA is a useful tool to layout the future strategy to manage the soil and groundwater protection and it should be utilized more often in future project.