The lack of a solid and strong environmental policy and environmental awareness in the last decades greatly contributed to the contamination of soil and groundwater around Europe. According to a study called “Progress in the management of Contaminated Sites in Europe” developed by the Joint Research Center in 2014 there are about 2.5 million potentially contaminated sites of which about 14 % (340,000 sites) are estimated to be contaminated . Among the countries surveyed Belgium-Flanders, Finland, and Lithuania appear to have the highest concentration of contaminated sites (Figure 1).
Figure 1: Estimates for Potentially Contaminated Sites across Europe 
Soil and water pollution can be derived from many anthropogenic activities, and in some case natural events. Figure 2 shows a graph with the main sources that were identify as having greater impact in soil and water contamination across Europe . As it can be inferred from the graph, that waste disposal and treatment and industrial and commercial activities are the key sectors that greatly contribute to pollution.
When any place is potentially described as contaminated it is crucial to understand the nature of the pollutant that is being released in the media in order to select the best remediation technology and plan the pre-remediation characterization campaign. Every contaminant has diverse impacts on human health and environment depending on their chemical and physical properties. Toxicity, carcinogenicity, and natural persistence, among others, are very important factors to determine while a substance in the soil or water is harmful and need to be removed. However, other characteristics such as solubility, potential or dispersion, biodegradation potential, mineral absorption potential are also key factors before selection of the best remediation technology to apply and continue in the development of new remediation technologies and detection methods.
Figure 2: Key sources of contamination reported in 2011 
The most common contaminant in soils and groundwater across Europe are shown in Figure 3. Heavy metals, oil and oil-derived compounds, and chlorinated organic solvents are the most prevalent contaminants in water and soils in Europe.
Figure 3: Most frequently contaminants. BTEX-Aromatic Hydrocarbons; CHC-Chlorinated Hydrocarbons; PAH-Polycyclic Aromatic Hydrocarbons 
Hans Bruyninckx, EEA Executive Director, reported: “Managing contaminated land in Europe costs an estimated € 6.5 billion per year”. This corresponds to an average annual national expenditure on the management of contaminated sites in on average about € 10 per capita . Although, these data indicate a decrease compared to 2006 (€ 12 per capita), there is still a need to find cheaper and more efficient remediation technologies that can be successfully applied to remediate polluted soil and water across Europe and the rest of the word.
Metal-Aid project aims to contribute to the development of an affordable in-situ remediation technology to minimize risk to human health and ecosystems.
Virginia Alonso de Linaje
 Liedekerke, M., Prokop, G., Rabl-Berger, S., Kibblewhite, M., Louwagie G. (2014) Progress in the Management of Contaminated Sites in Europe, JRC Reference Reports, European Union.
 http://www.eea.europa.eu/highlights/soil-contamination-widespread-in-europe accessed on: 03.02.17