Flödesmätning i spillvattennätet i Täfteå samt analys av mätdata

Sammanfattning: Additional water, namely water with another origin than sewage water that requires purification, is common for all Swedish waste water systems. This is not conspicuous considering the construction of the pipeline system and the external load that effects the pipelines. However these are not reasons to ignore the problem, there should be measures to solve it as far as possible. Additional water causes overloaded waste water treatment plants and pump stations. Additional water may also lead to flooding of basements and unnecessarily overflow. All these together results to large costs for the society, both economic and environmental costs.      The urban district Täfteå outside of Umeå is not an exception, there is already established that the sewage network is burdened with additional water. However the problem area needs to be located to be able to focus the measures. It is economical as well as time demanding to take action therefore means should be focused where the most benefit is received. This master thesis is conducted by using flow meters in the waste water system of Täfteå divided in part areas. The first area is placed southeast of the river Täfteåån the runs through the district and is named Björken. The second area is placed on the eastside of the river and is named Stugan. The last area is placed on the west side of the river and is named Halängesvägen. The aim of the work was to locate the area with the largest amount of additional water with expectation to declare some areas as not in need of means. The purpose was to give VAKIN, responsible of the water distribution for Umeå, opportunity to focus means in the worst problem area. The result confirms that Täfteå is affected by additional water in waste water system. The area that indicates the most amount of additional water where the area east of the river Täfteåån. When comparing the flow received by the meters with the flow calculated theoretically the area called Stugan had the largest divergence. The flow meter indicates that the source of the additional water, at measuring place Stugan, could be leak and drainage water. However the flow measurement would need to be extended to receive a more reliable result.