Analysis of groundwater flow dynamics in a contaminated area and the influences of the ATES system of the High Tech Campus Eindhoven

Abstract

The HTC campus Eindhoven is contaminated with chlorinated hydrocarbons, tetrachloroethene (PCE), trichloroethene (TCE), cis/trans-dichloroethene (DCE) and vinyl chloride (VC). It was assumed that the contaminants would be captured by the Dommel river, this turned out not to be the case. Cis-DCE and VC (measurement started 1995) compounds appear in east and south of the source area. How is this possible? The subsurface describes a complex groundwater infrastructure; the drinking water production Aalsterweg middle deep, the Philips ATES system, the Dommel river and the heterogeneity of the subsurface are active mechanisms in the Boxtel and Sterksel aquifer. From reconstruction of flow lines and differences in hydraulic head appeared that the eastward direction can be explained by the attraction of the Aalsterweg production wells. The southern appearance cannot be explained with only the effects generated by Aalsterweg and the ATES system. The infiltration character of the Dommel, the tilted less permeable layer(s) and the possible acceleration as result of the construction of observation wells contribute to the southwards motion. On basis of the available data it can be said that the last year’s no further concentration increase occurred in the southern part of the HTC campus. The contamination is moving to two production wells (22-PP001 and 22-PP014) and concentration of VC increasing towards these wells. The southward displacement is near the ATES wells, if the contaminants reach the capture zone, further spreading due to interaction between clusters will occur. Active sampling of the production wells and the ATES wells is recommended.