The Baltic Sea problems in context of erosion always have been very topical and since ancient times have been caused by uncontrollable and unpredictable natural factors (storms). These factors combine with the impact of human economic activities of the direct effect of factors -building offshore and aquatorium, deficit of sediment and marine dredging and growth of recreational tourism growth that promote load of coastal vegetation and dune relief. The identification of costs and benefits is significant step for evaluation of the impact of the Project and usefulness of the costs. The positive impact or benefits can occur at once, after a while or long term perspective. The economic evaluation techniques particularly cost-benefit and cost-effectiveness analysis for coastal protection in this case used for ascertain the most effective alternative. The sensitivity analysis was made for verifying impact of alternatives on taken solution. The aim of research is to verify the economic methods for application to coastal management in Latvia. The world’s coastal scientists believe that the future of coastal policy will become increasingly polarized and discussed; therefore, gradual implementation of the assessment process and development of socio-economic indicators is recommended.

Soil and groundwater as the leachate may contaminate surrounding watersheds, thus different pollutants from closed dumps and landfills pose significant risks to human health and ecology. Pollution may lead to soil and water degradation however it might be diminished through sustainable dump site closure projects and processual management. Several decades of clays and clay minerals studies lead to modified clay composites concept that is one of the potential promising solutions for building the landfill covering material and serve as capping biocover layer at the same time. As humic substances are constituents of soil organic matter, pollutants can be sorbed on the surfaces of complex molecules. These kind of humic acid-clay mineral composite materials thus might become as low cost building material component − covering material. Construction of such layer is to be performed as a combination of clay-humic composites and landfill mined fine fraction of waste with small amendment of natural soil. Several hypotheses that are already proven has to be mentioned: a) Clay minerals produce composites with humic substances; 2) Clay-humic complexes reduce through sorption both organic and inorganic pollutants; 3) Low risk of toxic by-products from landfill mined waste fine fraction can be the problem; 4) Such composites mostly would trap toxic contaminants (e.g., pharmaceuticals) found in reworked fine fraction of waste. The aim of the work is to provide alternative solution for landfill closure by giving theoretical considerations from multidisciplinary knowledge of environmental engineering, chemistry and waste management.