Modeling and Remediation of Ground Water Contamination at the Engelse Werk Wellfield |
| |
| Authors: | Xichuan Wang Truong X Ngo Yangxiao Zhou Jan C Nonner |
| |
| Institution: | Xichuan Wang;received an M.Sc in Quaternary geology from the China University of Geosciences in 1988, and an M.Sc in hydrology from the International Institute for Infrastructural, Hydraulic and Environmental Engineering, the Netherlands, in 1995. Currently he is a research assistant at Concordia University, Montreal, Canada. His research interests are subsurface transport of contaminants and restoration of aquifer systems. Truong X. Ngo;obtained an M.Sc in civil engineering from the Delft University of Technology in 1994. He has been working as a hydrologist for the Water Supply Co. of Overijssel since 1985. His tasks include the assessment of impacts of ground water extraction on the environment and the protection of wellfields. Yangxiao Zhou;has been at the International Institute for Infrastructural, Hydraulic and Environmental Engineering (P.O. Box 3015, 2601 DA Delft, The Netherlands) since 1990 and is currently an associate professor in hydrogeology. He received an M.Sc in hydrogeology in 1985 and a Ph.D. in 1988 from the Chinese Academy of Geological Sciences. His research interests are in the application of geostatistics and time series analysis to the design of ground water monitoring networks, optimization of ground water systems, and development of knowledge-based systems for ground water pollution assessment and remediation. Jan Nonner;obtained an M.Sc in hydrogeology at the Free University of Amsterdam in 1972. He's spent most of his career as a practicing hydrogeologist in various countries, being involved in a wide range of ground water projects. He joined the International Institute for Infrastructural, Hydraulic and Environmental Engineering in 1989 and is currently an associate professor in hydrogeology. His duties include lecturing and research on topics of ground water exploration, ground water modeling, and contaminant transport. |
| |
| Abstract: | Contaminants have been threatening the Engelse Werk wellfield located between the town of Zwolle and the IJssel River in the Netherlands. Chemical analysis of water samples taken in production wells, both at the IJssel River and near the Zwolle railway station, indicated elevated concentrations of mainly organic contaminants including benzene, bentazon, acenaftene, trichloroethane, and bromacil. Immediate contaminant prevention and remediation measures are needed to safeguard the production wells. Ground water flow and transport models were developed to assist in the design of remediation strategies. Ground water flow models indicated that the IJssel River and a waste disposal ditch at the railway station are within the capture zone of the wellfield. A chloride transport model simulated minimum travel times in the order of four to 13 years for contaminants in the IJssel River to reach the production wells of the wellfield. A transport model for benzene was set up to advise on the remediation measures to be taken at the waste disposal ditch to clean up the contamination in the upper aquifer between this site and the Engelse Werk wellfield. The designed remediation system consists of 12 pumping wells with a combined capacity of 1650 m3/day. The system is capable of reducing the benzene levels at the threatened production wells at the Engelse Werk wellfield to a permissible level below 0.1 μg/L within a period of 5 years. |
| |
| Keywords: | |
|
|
