Characterisation and monitoring of in-situ remediation of chlorinated hydrocarbon contamination using an interdisciplinary approach (MIRACHL)

To meet future challenges in urban development with denser housing and sustainable water resources, society needs to take actions. Densification of housing is met by expanding housing into old industrial areas often contaminated and water resources are already affected in some areas by over exploiting, pollutants spreading and a changing climate leading to changes in recharge.
Growing concerns are the ca 2000 sites in Sweden contaminated with carcinogenic chlorinated hydrocarbons (dry-cleaners and industrial solvents). In Sweden, the main remediation technique is excavation and landfilling, i.e. moving the pollutants from one site to another. This strategy leads to large transports and exposure of dangerous compounds. SEPA recommends the use of in-situ methods, which can lead to large savings for clean-up. It will also contribute to EU Water Directive requirements and help us reach our national environmental objectives, good-quality groundwater and a non-toxic environment.
Today, the monitoring of in-situ remediation actions and confirmation on “good enough” is very uncertain, due to the existing current techniques with point source monitoring. In this project, we integrate monitoring with geophysical (Direct Current resistivity and Induced Polarization, DCIP) and physical and biogeochemical characterization (PBGC) and compound-specific isotope analysis (CSIA) methodologies to better understand and follow the in-situ remediation processes. Continuous geophysical observations during the remediation, will together with biogeochemical sampling and analyses, help follow the underground development. With our combined technique approach, we can retrieve a comprehensive coverage of underground changes, reduce uncertainties and costs for monitoring and follow-up of the in-situ remediation.