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Towards Improved Groundwater Vulnerability Assessment

Final Report Summary - IMVUL (Towards Improved Groundwater Vulnerability Assessment)


Executive Summary:

Marie Curie ITN IMVUL (Towards improved groundwater vulnerability assessment)

The IMVUL network is a Marie Curie Initial Training network under EU Framework 7 (Grant agreement 212298). The network started on the 1st October 2008 and ran for 4 years. The network consisted of 8 partners from universities and research institutions and 13 associated partners from industry in the United Kingdom, France, Spain, Italy, Israel and Norway. The network employed a total of 15 fellows (11 ESRs and 4 ERs). The principal aim of the IMVUL network was to train researchers in the major issues, scientific challenges and operational problems in groundwater vulnerability that face the groundwater industry today, through a combination of research and industry related training.

Contact Details: Noelle Odling (IMVUL coordinator), School of Earth and Environment, University of Leeds, UK. Email: n.odling@see.leeds.ac.uk. More details can be found at the network website: http://earth.leeds.ac.uk/imvul/index.htm .

Background: There has been an increasing realization over the last 30 years that to preserve water quality and quantity in Europe, measures at both European and national levels are needed. Our groundwater resources are at risk from a wide variety of stresses including point and diffuse source contamination and over-abstraction. Minimizing this risk requires a good understanding of the physical, chemical and biological processes involved and the development of tools to assess groundwater vulnerability, aid water management and design protection strategies. To meet the challenges imposed by the new EU Water and Ground Water Framework Directives, the water industry throughout Europe is already significantly expanding, creating an increasing demand for appropriately educated graduates.

The network objectives were to increase our understanding of the fundamental processes relevant to groundwater vulnerability, to develop improved prediction tools that can contribute to the protection and sustainable use of Europe's groundwater resources and to provide an interface between researchers and the water industry.

Network Research Results

Research falls into three main categories: aquifer case studies, laboratory-based research and modelling techniques.

Aquifer case studies: A range of groundwater vulnerability issues were investigated through a series of case study aquifers in UK, Italy, Spain, France and Norway. In the Chalk aquifer (UK), monitoring in the soil and in a tunnel at depth was used to characterize the flow regime in the unsaturated zone and estimate travel times for contaminants. Also in the Chalk Aquifer, the use of spectral techniques for characterizing semi-confined aquifers and their vulnerability from borehole water level and barometric pressure data have been developed and applied. In the fractured crystalline Ploemeur aquifer (France), methods for using groundwater temperature as a tracer have been developed and applied to determine connectivity of fractures and denitrification rates. In the unconsolidated sediments of Llobregat Delta aquifer, field experiments investigated methods for minimizing emergent pollutant concentration, not removed in water treatment plants, in artificial recharge schemes. In the glacial sediments of the Øvre Romerike Aquifer in Norway, a low cost micro-screen multilevel sampler was designed and installed, and used to investigate groundwater chemical stratification as a guide to vulnerability.

Laboratory studies: Laboratory based projects include studies of biofilm development, detection and properties of emergent pollutants and control of water quality in artificial recharge schemes. New micro-cathode tomography methods of visualizing 3D pore structures are coupled with voltammetric electrochemical sensors for in situ detection of bacteria activity in columns experiments and used to characterized the effects of nutrient levels and heavy metal concentration on bacterial activity in the subsurface. Methods for detecting the hormone estrogen and related substances (endocrine disruptors) at ng/l concentration levels have been developed. Experiment results have shed new light on the evolution of these substances in the subsurface, showing that they are very persistent. Column experiments were used to simulate the behavior of emergent pollutants in artificial recharge schemes and to identify effective substrates for minimizing their concentration in recharging waters.

Modelling studies: New analytical and numerical methods have being created and existing models further developed to create a range of modelling tools for investigating problems relating to aquifer vulnerability. A number of geostatistical approaches for characterising aquifer heterogeneity have been tested and compared to improve assessment of aquitard integrity. Theoretical developments include non-Fickian transport of pollutants in heterogeneous media using the continuous time random walk (CTRW) approach, and the use of stochastic methods to investigate coupled flow, mixing, dispersion and reactive transport on a range of scales. Existing numerical models of flow and transport in fractured porous media have been further developed to include precipitation and dissolution (including biofilm development) and improved fracture system discretization developed to advance prediction of groundwater flow and contaminant transport in fractured rocks.

Interaction between these three research approaches has been an important part of IMVUL research. The case study aquifers were used to drive lab experiment design for biofilm development, waste water quality for artificial recharge, and emergent pollutant behaviour in groundwater. The case study aquifers and lab experiments have driven the development of modelling techniques including geostatistical simulation techniques and improved methods for groundwater flow and transport modelling.

Network Training Events: Research activity is complemented by a series of network-wide training events and annual meetings, comprising: Complementary Skills Training workshop (:Leeds, UK), summer school ‘Flow and transport in porous and fractured media’ (Cargese, Corsica) , Groundwater Modelling Workshop (Milan, Italy), Groundwater Biogeochemistry Summer School (Edinburgh, UK), and the field trip ‘Unconsolidated and fractured aquifers in Norway’. The end-of-network conference ‘Groundwater Vulnerability - Emerging Issues and New Approaches’, open to speakers from outside the network, was held in Paris, 9 to 12 July 2012.

A pdf of this publishable summary (MCITN_212298_IMVUL_Final_Report_Publishable_Summary.pdf) with network logo and images, is appended to this Final Report.