Year Fortune Corp. is situated in the region of Hsien His of Changhua Coastal Industrial Park where the previous manufactory was belonged to the predecessor of Year Fortune Corp., named Concord Chemical Industrial Co., Ltd. In 1999, Concord’s processing plant was burned down where the main product in that plant is dicumyl peroxide (DCP). Because of the emergent rescue for the conflagration, the raw material of DCP (cumene) in the storage tank polluted the local groundwater. Although Year Fortune Corp. had already drafted a proposal to investigate and estimate the level of pollution, the implementation was obviously delayed indeed. Therefore, according to Article 12, Paragraph 1 of ‘Soil and Groundwater Pollution Remediation Act’, the Environmental Protection Bureau of Changhua County substituted for Year Fortune Corp. to carry out the investigation and estimation of the pollution level.
Product of their previous manufactory was a cross-linking reagent (DCP) what the raw materials mainly include cumene and NaOH (1 and 20 wt%). Our investigation has collected the literatures and chemical properties from Materials Safety Data Sheet (MSDS), correlated to these raw materials of DCP. Cumene has a density of 0.862 and is insoluble in water; another pollutant, phenol, has a density of 1.06 but is soluble in water. In addition, there were several experiments performed in our investigation to understand its hydrological and geologic information, such as cone penetration test (CPT), soil characteristics analysis, slug test, and water level measurement. From our survey result, the local soil can be categorized as sand or silty sand. The hydraulic conductivity (K) of groundwater is between 10-3~10-4 cm/s. The direction of groundwater flows from north east to south west. The local soil characteristics facilitate the transmission of pollutant. Moreover, the influence of tide on the groundwater level is more significant in the west side of manufactory than that of inland (east site).
Samples of soil and groundwater were taken 10 and 40 times, respectively. The analytical results of soil show that cumene concentration of S07 is 895 mg/kg and those of groundwater show that phenol concentration reaches 3.04 mg/L in the monitoring well of SW-15 (groundwater criteria of Taiwan is 0.14 mg/L). Another pollutant, cumene, exhibits the maximum concentration at 177 mg/L in GW-05 monitoring well (0.7 mg/L, the triennial average of groundwater criteria in the industrial park, suggested by the Department of Environmental Protection of New Jersey State). Hot spots of polluted groundwater are mainly located in the processing areas of crystallization, cumene storage, UV stabilization as well as its greenbelt. The contaminated depth of phenol and cumene ranges between -2 to -9 m and -2 to-5 m in the groundwater, respectively. However, natural diffusion of groundwater, variations of groundwater level between dry and flood season, tidal effect, as well as their own pumping in the manufactory might result in a gradual spread over the region of factory. Besides, not only the relatively low concentration of dissolved oxygen, Fe3+, NO3-, and SO42- but also the negative oxidation-reduction potential (less than -100 mV) indicates that the environment around those hot spots is in a reductive state. Because of the reductive state, an anaerobic biodegradation should evidently occur within those hot spots. With respect to the estimation of contamination, the volume of contaminated soils and groundwater are 37,408 m3 and 66,795 m3, respectively.