Contaminated sites pose a risk to groundwater and surface water, being a source of organic and inorganic contaminants that can damage drinking water resources and ecosystems. Every year the Regions of Denmark spend DKK 400 million on contaminated sites to provide reliable data for risk assessment and clean-up, and Denmark is a world leader in the area. GEOCON brings together leading Danish and international expertise to address the need for new and more efficient field approaches for site investigations and risk assessment. GEOCON aims to develop a set of new integrated contaminated site characterization tools including systematic geologic characterization methods, contaminated site monitoring and mapping, geophysical mapping, and groundwater contaminant discharge measurement methods. GEOCON will develop new technologies, such as geophysical methods that not only map geology, but can also determine the extent of groundwater contamination. These new geophysical methods will move beyond traditional approaches that rely on differences in electrical conductivity (widely used to detect saline groundwater), to methods that can detect the organic contaminants that are the greatest threat to our water resources. The methods will be benchmarked at 3 landfill sites, but will have general applicability to all types of contaminated sites. Landfills are important because there are 2,500 of them in Denmark, they are amongst the biggest contributors to degraded water quality in streams, and their discharge to streams is not well understood. The results from GEOCON will be rapidly transferred to Danish consultant companies and used in Denmark and internationally, in particular in developing countries (e.g. China) where groundwater contamination is a pressing issue.