Kompostering i kommunal regi: en fallstudie i Arvika Parkförvaltning

Abstract

Arvika Fastighets AB is a municipal subsidiary tasked with managing all green areas in the municipality, with a strong focus on the City Park and plant beds in the city centre. These areas generate large amounts of green waste, which is currently transported to the municipality's composting area at Lycke. Currently, the material is piled up and turned once a year without using the resulting soil for flowerbeds, lawns, and shrub/tree plantings. The purpose of the study is to determine if Arvika can compost the green waste in a more efficient manner and produce weed-free soil ready to be mixed into various substrates for different purposes. Interviews with the Swedish Church and several municipalities in Sweden have been conducted to learn from their experiences and knowledge of how they make their composting work. Supplementary literature studies, covering various composting methods and their compositions, were done to understand the different approaches. An empirical experiment was conducted at the Lycke composting area in early October 2023. A covered compost heap was constructed measuring 2x15 meters. The material was taken from the summer flowerbeds in the City Park when they were cleared for autumn bulb planting. The experiment led to a better understanding of the amount of material, machinery, and time needed to construct a larger compost heap. Based on the results from gathered information (interviews, literature studies, and the experiment), Arvika Fastighets AB is recommended to use a composting method according to the string/stack composting technique. This method quickly and effectively transforms the material into fine, weed-free soil. The method requires more work regarding temperature measurements, aeration, and turning, but it is simpler in nature. Green matter can be mixed in any way, and the height of the compost pile provides a higher temperature that kills weeds. Lycke can continue to be the site used for composting. However, some investments are required to manage the chosen method and any potential scaling up. Currently, soil is purchased for various needs in the municipality. The finished compost soil can be a valuable addition and eventually replace the purchased soil.