Prof. Dr. P. Huggenberger, K. Meier*, Dr. R. Page, Dipl. Hydrol. S. Scheidler, Dipl.-Ing. (FH) S. Wiesmeier

Groundwater extracted from alluvial aquifers close to rivers is vulnerable to intermittent faecal contamination due to infiltrating river water. Infiltration is often increased during high discharge events, when the levels of waterborne pathogens are also increased. Water suppliers with low-level treatment thus rely on procedures and information on system state (actual groundwater quality) to manage the resource and maintain drinking-water quality. Early detection of potential river-borne microbial contamination in the aquifer can provide drinking-water suppliers with extra time to react to the incoming river-water infiltrate and manage groundwater extraction accordingly.

This project combines time series of groundwater quality observations using a proxy-based approach to groundwater monitoring: parameters used in the time-series analysis include continuous groundwater head, temperature, electrical conductivity, turbidity, spectral absorption coefficient, particle count and pH. In addition, event-based studies focus on microbial quality by analysing faecal indicators (E. coli and enterococcus).

The detection of potential contamination events is based on multivariate analysis by means of principal components and self-organising maps. The results of the analysis allow integration into the management system of drinking water suppliers by means of a Critical Control Point (CCP) approach.

The project is supported by the CTI (12611.2 PFIW-IW, 8999.1 PFIW-IW) and Endress+Hauser.

* Geschäftsführung Endress+Hauser Metso AG, Reinach