Investigation methodology focusing on field techniques

The NORISC project has established a decision tool as core part of a decision support system (DSS) that combines the data in the catalogue of contaminated site characteristics and the user requirements with the register of potentially suitable investigation methods. This tool is based on the evaluation matrix that selects technically suitable sampling, geophysical, (hydro-) geological techniques, as well as field and laboratory analytical measurement and testing methods, ranking them by their cost and time attributes. Using it, scientists, environmental engineers and consultants can easily assort an optimal set of different kinds of methodologies for a more reliable, cheap and fast on site and in situ investigation.

A computer programme for the selection procedure has been developed based on extended data provided in a database. At first, the input data sets were harmonised, then the software based on Access and Visual Basics was designed.

Output from the NORISC decision support software tool is provided in the form of an excel sheet. The field analytical methods for the determination of contaminants in soil, groundwater and soil gas are listed on separate sheets that are technically suitable for the site described by the input procedure. Cost and time attributes are displayed as well, and moreover the cheapest and fastest technique is selected for each measurement. Suitable laboratory analytical methods are listed, too. In terms of geophysical screening, geological and hydrogeological characterisation and sampling techniques, the software provides the best combination of the different kinds of methods for a really effective site characterisation.

Site investigation strategy (SIS) In addition to the NORISC decision tool software, a site investigation strategy (SIS) was prepared that enables a flexible and dynamic field investigation approach. Its key elements are the combination of geophysical screening with field investigation techniques, as well as the daily evaluation of results and adjustment of the investigation plan. During the site investigation the location of sampling points is to be recorded by GPS and downloaded to a portable computer unit together with measured determinant values. Data processing is to be carried out on-site, too.

Field testing

NORISC went through several test phases and the objective of testing the NORISC decision tool software and investigation methodology at different sites was to evaluate the approach in practice and to make adjustments improving its functionality and acceptability. It was even aimed to prove that the new integrated investigation approach can really be applied to different types of polluted sites.

The testing team, consultants in environmental engineering, developed a flexible stepwise work management plan based on their field experience in order to formulate a principal concept for the investigation procedure of brownfields and potentially contaminated sites.

The NORISC Test Site Evaluation Group (TSEEG) chose four representative European contaminated sites for trial. Each tested site had its own site history and specific contamination profile.

NORISC case studies to prove the new interdisciplinary approach.

clayton Umwelt-Consult GmbH organized, planned and executed the field work based on the mentioned flexible work management plan. The work was carried out by the contribution of subcontracting companies for example the geo-technical service or geophysical survey. All scientific investigations were made on site requiring intensive teamwork due to the interdisciplinary approach. Chemical analyses were performed, if possible, with innovative portable field equipment (GC/MS, miniaturized, XRF or Immunoassay Test Kits) implemented in mobile laboratories (van or truck). Applied on-site analytical tools for the case studies with the NORISC approach. Contaminant Investigated Medium Analytical Tool Device Heavy metals soil XRF Spectrum Analyser 7000er series BTEX soil/water/soil gas GC/TCD 3000 Micro GC TPHs soil Infrared-Spectro-meter Petroleum Hydrocarbon Analyser TPH Plus TPHs water GC/FID HP 5890 GC TPHs/PAHs soil GC/MS EM 640 Chlrinated Hydrocarbons soil/water GC/TCD 3000 Micro GC PAHs soil Immuno-assays EnviroGard PAH in Soil Phenols soil Colorimetric test Phenol test in soil Arsenic water Colorimetric test Arsenic Quick 5 Aldrine soil Immuno-assay EnviroGard Chlordane DDTs soil Immuno-assay EnviroGard DDT

Collaborating partners Test Site Team Clayton Umwelt-Consult GmbH Ludwigshafen, Germany University of Ferrara & Florence, Earth Science Department, Italy Evaluation Manager Alecos Demetriades, IGME, Greece Test site managers Karl-Michael Gerhold - City of Cologne Dr. Bertil Engdahl - EPA Stockholm Dr. Alessandro Gargini - University of Ferrara Balázs Morvai -AGRUNIVER HOLDING Ltd Subcontracted Companies Cologne test site, Germany Land survey City of Cologne, Germany Geofact GmbH, Bonn, Germany Klingen & von der Bruck GmbH, Pulheim, Germany Mobilab Hamburg MM1 Umweltanalytik GmbH, Hamburg, Germany AnalytiCON Instruments GmbH, Königsstein, Germany Stockholm test site, Sweden Tyréns Infrakonsult Stockholm, Sweden AnalytiCON Instruments GmbH, Königsstein, Germany Coring Systems, Gernsheim, Germany EPA Stockholm, Swedish Geological Survey, Stockholm and University of Uppsala, Sweden Massa test site, Italy PAGANI Geotechnical Service, Milan, Italy University of Ferrara and Florence, Earth Science Departement, Italy GEORISORSE Italy, Sinalunga, Italy Coring Systems, Gernsheim, Germany AnalytiCON Instruments GmbH, Königsstein, Germany Balassagyarmat test site, Hungary PAGANI Geotechnical Service, Milan, Italy Dr. Wessling Laboratorium Kft., Budapest, Hungary AGRUNIVER HOLDING Ltd, Gödöllö, Hungary University of Ferrara and Florence, Earth Science Department, Italy GEOMEGA Ltd. & Tanagra Ltd., Budapest, Hungary CASON PLC Ltd., Érd, Hungary

GIS-map plotted on-site with concentration of TPH in soil, overlaid on historical facility map. Production processes and the contamination profile could be interpreted easily. Due to the fact that the daily analytical, hydrogeological and geophysical results were entered into a visualization software tool, maps could be plotted directly in the field. Therefore, the obtained data were evaluated daily on site and the next day action plan was adjusted dynamically according to the new findings. In this way, the sampling and drillings could be carried out more efficiently and in a more flexible manner. At the end of the field investigation a complete picture of the site and its contamination profile, as well as all necessary data for an expert report were available. The NORISC scientists and engineers followed the usual Quality Control (QC) and Quality Assurance (QA) scheme to ensure the validity of the obtained data sets. Further on, verified and rapid soil/groundwater extraction methods, developed especially for field analysis, were used to speed up the process of data acquisition.

All analytical equipment that was used during the NORISC case studies has given evidence concerning cost-efficiency and accuracy in producing reliable data. NORISC has proven that the pollution hot spots of a contaminated site could be localized in a more efficient way, compared to the conventional site investigation strategy applied in former investigations at the same site. Map with Arsenic distribution after two days of NORISC investigation on a test site. Values are weighted in quartiles. Guidance of drilling and investigation decisions was made by dynamic work plans.

Evaluation of NORISC methology

Is NORISC methodology really... Yes, because of ... We prove it by... cheaper ? The mobile-laboratory does not have the overheads of a conventional laboratory and, therefore, a higher number of samples can be analysed in less time in order to delineate contaminated and uncontaminated parts of the investigated property. A small number of samples, only those that require analysis with higher accuracy, is sent to a conventional laboratory for a cross-check. Less drill-holes for analytical measurements to delineate the precise volume of contaminated soil. Less drill-holes for the hydrogeological survey due to identification of sub-surface geological structures by geophysical screening. Identification of buried potential pollution sources, such as tanks and pipelines by geophysical techniques. On-site positioning and data management facilitate flexible sampling, less and better-located drill holes Highly polluted areas can be outlined with cheap test methods. Cost-effectiveness analysis to evaluate the economic efficiency of the site investigation carried out by using the NORISC approach by combination of methods of different disciplines Comparison of test investigation with former regular investigation completed at the test site faster ? Time can be saved using on-site analysis and tests that provide immediate results. The volume of analytical and (hydro-) geological investigation is decreased by better location of sampling points. Decisions on further investigation steps can be made on site facilitating dynamic work plans Time-effectiveness analysis of the site investigation and comparison with duration of regular method and more reliable ? Geophysical screening provides full-coverage information of the site, and not only to the different points where drilling is conducted. Interdisciplinary work provides complementary data, and information, thus making the contaminated land assessment procedure more efficient. Evaluation whether the combination of different methodologies and their application really reduces uncertainties in contaminated land assessment

In addition, an appropriate assessment and evaluation procedure was defined, including quantitative and qualitative criteria, in order to verify the precision of delineating contaminated and uncontaminated land, time- and cost- effectiveness, by applying the NORISC methodology. The results of the field examination carried out according to the decision tool output were compared with the results from former conventional investigations.

If the results of both investigations are comparable, it is a signal that the new NORISC approach works, and of course, the field investigation team has applied the recommended methodology efficiently. By utilising the evaluation results, which essentially provide a quality control for the NORISC procedure, refinements have been made from the first to the fourth test site investigation.

The geochemical distribution map shows that the performance of NORISC was better in the delineation of the arsenic pollution than the previous investigation. In fact this is a case where the catch phrase "the solution to pollution is not dilution", applies fairly well, because the previous investigation by sampling the first 2 metres of soil has effectively diluted the pollution, which was mainly concentrated in the first 20-30 cm. This also a case of how much one can rely on the "status quo" data to evaluate the performance of NORISC. (The pink-coloured neo-anomalous area with As values over 50 mg/kg has been defined by the previous investigation results of the first 2 metres of soil sampling. On this map are presented the results of the deeper soil samples from 200-400 cm and 500-800 cm collected by the previous investigation, which show very low arsenic values.)