Summary: | The aim of this project was to look into ten small sewer systems in the municipality of Laholm, in Sweden, in order to work out common assessment grounds for them. The sizes of the systems for purification of wastewater were within the range of 25 to 2000 population equivalents. Our method was to study literature, the laws and regulations applicable and the files at the municipality. The conclusion is that every sewer system is different and every situation is unique. We concluded that based on laws and assessment grounds sewer systems equal in size and pollution load ought to have similar demands attached to them. Four of the sewer systems are in need of adjustments or renovations. One sewer system in particular, Hishult, needs large-scale adjustments and improvements to live up to the demands attached to it. This sewer system is where we think the focus from the municipality ought to be the strongest, based on the result from this review. It requires most effort, time and money, to get it running with least amount of environmental impact. We also suggested levels for degree of purification for all of the sewer systems. As a common ground we set the demands equal to the ones for private sewer systems. The demand for purification of phosphorus was adjusted to if the system was equipped with chemical precipitation or not. Subsurface filters are left without measures. The focus of demands on systems of that kind is set to new construction or full scale restoration.
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