Development of a Mass Flow-Based Spring Capture Zone Delineation and Immission Modeling Tool for Drinking Water Pollution Risk Management - SPRING
Coordinating Institution:
CRP Henri Tudor
Contracting Partner(s):
Laboratoire National de Santé ,
University of Luxembourg ,
Administration de la Gestion de l'Eau
Other Partner(s):
Helmholtz Zentrum, München (D) ,
Forschungszentrum Jülich (D) ,
University of Freiburg (D)
From: 01/02/2008
To: 30/06/2010
Budget: 499,650.00€
Contact(s):
Gallé Tom
,
Zwank Luc
Summary
The project aims at quantifying pesticide fate in the soils and the fractured rock system of the Luxembourg Sandstone and at developing a tool that will use plot-wise mass flows to identify contributing surfaces to a contaminated spring.
After the drilling of the piezometer in fall 2008, the SPRING team focused on pesticide fate modeling and necessary calibration/validation experiments in 2009. In spring the TDR profile has been dug in on one of the experimental fields of the Steinsel plateau. TDR probes continuously measure water content changes in a soil profile of 15 m width and 2 m depth down to the parent rock. These data will be used for the hydraulic calibration of the PEARL pesticide leaching model. The model has been implemented based on previous year’s Bromide leaching tests applied to two fields and first runs have been performed. Precipitation distributions have been generated from official rain gauge data to be able to simulate several decades of pesticide fate in soils. After a long conceptual and diplomatic preparation a spatially extensive sampling campaign for pesticide residues was conducted on the agricultural plots of the Steinsel plateau. These data will be analyzed with geostatistical tools for intra and inter plot variability. The results will serve to evaluate long term simulations of pesticide fate in the soils. The capture zone delineation tool was developed and is currently tested in a first version. Spring observations were carried on at a weekly pace on selected springs and in the piezometer. The piezometer is currently sampled at a fracture in the unsaturated zone which allows capturing recent groundwater recharge. For that purpose the piezometer has been equipped with a packer to retain the water. The first year of isotope measurements have been evaluated and confirmed first estimates of mean ground water residence times of around 10 years. Very little preferential flow is detectable in the springs around the Steinsel plateau. The team submitted a follow-up project in the Core program on pesticide degradation measurement with isotopic methods which has been accepted by FNR and will start in 2010.
Project Website
Figure 1: Drilling & Cores - Piezometer drilling on the Plateau of Steinsel Background : Soil coring equipment. Front : Soil cores taken each meter
Figure 2: Application of Bromide Tracer on a maize field