4.37. The description of the disposal system should record all of the information and knowledge about the disposal system and should provide the basis on which all safety assessment is carried out. Information will be obtained and knowledge about the disposal system will evolve and mature as the project progresses and assessment is carried out in an iterative manner. As knowledge is developed, it should be used to determine future needs for system characterization and facility design. The system description should contain, depending on the type of disposal facility, information on the following: @@- The near field, including: (i) the types of waste (e.g. the origin, nature, quantities and properties of the waste and the radionuclide inventory); (ii) system engineering (e.g. waste conditioning and packaging, disposal units, engineered barriers, cap or cover of the disposal facility, drainage features); and (iii) the extent and properties of the zone disturbed by any excavation or construction work;@@- The far field, e.g. geology, hydrogeology, hydrology, geochemistry, tectonic and seismic conditions, erosion rates; @@- The biosphere, e.g. climate and atmosphere, water bodies, the local population, human activities, biota, soils, topography and the geographical extent and location of the disposal facility.