Water drainage from a Swedish waste treatment facility and the expected effect of climate change

Abstract

The waste treatment facility, Sobacken, is located south of Borås, Sweden. At Sobacken there is a lake built to collect the leachate from the area. Leachate is a term for water that has the potential of carrying environmentally hazardous substances, in this case water that might have passed through waste. This thesis focused on the development of a hydrological model that from common climate variables is able to model the water level of the leachate lake. The model was based on the theory that all incoming precipitation for the catchment will either end up in the leachate lake or are removed by either evapotranspiration or groundwater recharge. The water will then either be pumped out of the leachate lake or be removed as open water evaporation. Since the area of the catchment was unknown this was estimated with a GIS analysis made with elevation data. The land area of the catchment was around 350 000 m2. The model was used to investigate how the water level of the leachate lake will be affected by a proposed climate change scenario. The climate scenarios used for this thesis were A1B, A2, and B1. The model gave reasonable results compared to other studies and showed for all three of the climate scenarios an increasing trend of the average leachate lake water level. This indicates that the lake will not be sufficiently large to handle the increment of leachate in the future. This in turn would lead to an overflow of leachate into the environment which has to be prevented