Density dependent groundwater modelling

Data management strategies for drinking water, The Netherlands

PWN is a leading drinking water supply company in The Netherlands. At various levels and under the umbrella of different projects Acacia Water supports PWN in their ambition to produce and distribute the highest quality drinking water to its customers. Amongst others, Acacia Water supported the development of data management strategies and the establishment of cause-effect relations with regard to contamination problems.

Recently, a series of shallow wells was reported to be contaminated with saline water. To find out the cause of these contaminations infiltration and simulation tests were performed. The hypothesis stated that the saline contamination was caused by ponding of rainwater around the wellheads during periods of heavy rainfall.

The simulations were performed with FlexPDE. FlexPDE is a modelling software that allows for a detailed analysis of integrated unsaturated and saturated density dependent flows. The results of the simulations, in combination with the infiltration tests, show that it is well possible that the wells were contaminated through ponding, as stated in the hypothesis. In addition to the contamination with saline water, a similar study was performed to pinpoint the source of an E. colli contamination in another well.

Next to contamination analyses, Acacia Water provided recommendations with regard to data management. The software that was being used to store and analyse hydro(geo)logical data had to updated. PWN wanted to improve data storage, exchange and validation. PWN commissioned Acacia Water to draw up the Terms of Reference for the update.