Data structure and types
A database/expert system has been developed for environmental risk assessment in (contaminated) soil, sediment, sludge, waste and construction material. The first step in setting up the database has been to identify the type of questions to be answered and to ensure that data are implemented in a manner that allow the desired cross comparisons between fields, the mutual comparison between test methods and establishing relationships between lab and field. The database contains results of laboratory experiments (pH-static experiments, column leaching tests, CEN tests, availability tests and diffusion tests) on more than 600 soil, sludge, waste and construction material samples. It also contains data on lysimeter studies and relevant field data that are linked with laboratory work. This makes the database/expert system a unique tool to study the behaviour of different recycled materials, the comparison of different test on wastes and on construction materials, the comparison of data from laboratory leaching, lysimeter scale studies and field measurements. Furthermore, the system can serve as basis for modelling the chemical behaviour and release of substances in different scenarios.
The type of data that are relevant for a database/expert system on leaching cover all kinds of materials, laboratory test methods applied in various jurisdictions, pilot scale test data, field leachate data, technical properties (density, permeability, ...), hydrological information, etc. The substances for which data can be implemented range from all inorganic constituents, organic contaminants to radionuclides. There are certain minimum requirements the information to be inserted should fulfil to be meaningful. This with respect to data presentation and interpretation (e.g., using geochemical models). For this purpose data should contain pH and liquid/solid ratio or exposure-time information.