Kan marin sand och grus utgöra ett subtitut för landbaserade naturgrustäkter? : En undersökning utanför Umeås kust

Sammanfattning: Sand and gravel are compounds that are directly needed in the fine fraction of making concrete. Concrete is used as a foundation in 90 % of the cases when establishing new buildings in Sweden. Usually, sand and gravel are taken from land based areas. These land based areas with sand and gravel are also needed for the cleaning of the groundwater. Groundwater is the source of drinking water in big parts of Sweden and should therefore not be jeopardized. In the marine environment, there are areas that possess sand and gravel that could be used instead of land based material, and therefore will not jeopardize the quality of drinking water. By learning how the law is regulated in marine sand and gravel extraction cases, looking at existing maps of the marine geology’s structure, learning about the environmental impacts and by looking at the technique that are used for extracting the material of the bottom of the ocean - this report shows the possibilities of marine sand and gravel extraction of the ocean floor outside of Umeå’s coastline. The result shows that there are a few areas that have the right material and lies on the right depth of the ocean floor, but these areas did not have the right thickness. Therefore, an extraction of marine sand and gravel at these areas (Area A and B) would affect the volume percentage. This could lead to a change of the bottom structure that destroys the recovery after the extraction and damage the marine environment.