Towards the development of a salinity impact category for South African life cycle assessments: part 2 - a conceptual multimedia environmental fate and effect model

In Part 1 of the series, it was shown that there is sufficient justification for the creation of a separate salinity impact category. In this paper, the fundamental basis of environmental life cycle assessments (LCA) is examined. The generalised model, and model simplifications on which the life cycle assessment methodology is based is examined. The formulation of a characterisation model for salinity, which is a local or regional problem, requires the development of environmental fate models. An environmental fate model currently in use to calculate equivalency factors for toxicity effects is evaluated in terms of its applicability for use as is, or in some modified form, to calculate equivalency factors for salinity. It is concluded that this model cannot be used, and a conceptual environmental fate model for salinity is proposed. The proposed conceptual model follows the same approach as models currently in use. It is proposed that a \"unit South African catchment\" be defined, and that non-steady state hydrological models currently in use in the country be used to predict the fate of salts in the various compartments defined for the \"unit catchment\". WaterSA Vol.30 (2) 2004: 241-251