Work Package 1 – Development of methods and concepts for integrated investigations (WP leader: Poul L. Bjerg, DTU)
The WP will develop and test methods and concepts for field investigations of contaminated sites. The primary goal is to provide methods for efficient plume identification and collection of reliable field data for contaminant mass discharge estimates from landfills. Two landfills previ-ously characterized by extensive investigations by the project consortia and regional authorities will be used as field test sites in the development phase. Here well-defined landfill leachate plumes exist, which impact groundwater quality and local streams. A third sparsely investigated landfill site will be selected to transfer the results from research based sites to “normal” contaminated sites (see also WP4). The sites will be selected in close collaboration with regional authorities, supporting drilling and chemical analyses. The consulting company, Orbicon, will be heavily involved in these investigations. An array of novel and state-of-the-art methods will be integrated in the work package:
i) Methods for creating improved conceptual geological models using the PM-approach (Klint et al. 2013 b), including polymorphological analysis /GIS analysis, and SiteEval for classifying glacial deposits (Klint et al. 2013a).
ii) In situ and surface geophysics using the El-log drilling method and 3D surface acquisition employing both current state-of-the-art instrumentation as well as the new system developed in WP3 (Gazoty et al. 2012).
iii) Flow fields around contaminated sites: State of the art hydrogeological characterization methods will be employed and compared to data obtained by PVPs. Geostatistical methods will be used to upscale local data to effective parameters to be used in solute transport models.
iv) Field scale contaminant plume mapping: El-log sampling and innovative analytical-chemical methods (Sørensen and Larsen, 1999; Damgaard et al. 2013).
v) Contaminant discharge zones to streams will be identified and mass discharge determined by various field methods: Multilevel samplers, drive point monitoring wells and existing boreholes; temperature measurements in streambeds and discharge quantification; stream bed and stream measurements of contamination; in situ and surface geophysics (McKnight et al. 2012; Milosevic et al. 2012).
vi) Contaminant mass discharge and model integration tools: Two current challenges in con-taminant transport modeling will be addressed. The first is to determine how contaminant mass discharge and the related uncertainties can be estimated efficiently and how the advanced field results can be integrated into practical risk assessment tools (Chambon et al. 2011). The second challenge lies in the joint calibration of contaminant transport models with multiple data types. Troldborg et al. (2010) demonstrated the value of joint calibration to concentration and head data in models to determine contaminant mass discharge. Here that work will be extended so that the models will also be conditioned on geologic, geophysical, and direct groundwater flow measurements.
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