Property-close Collection of Fat, Oil and Grease (FOG) from Households. – Experiences from a Swedish Case Study.

Problems related to content of fat, oil and grease (FOG) in wastewater is an increasing problem in Sweden. FOG can cause clogging in the sewage system and subsequent flooding and disturbance of processes in waste water treatment plants. The problem has previously been mostly been related to release of large quantities of FOG from restaurants and large scale industries which has caused problems in municipal sewage systems. However, similar problems have more recently been detected more frequently in relation to disposal of FOG from households into the sewage. This study evaluated a full-scale experiment with source-separation of FOG from households in a residential area in Malmö, Sweden. Results from the study show that on average 0.35 kg/household and year of FOG was collected during the trial period. Households were positive to the introduction of a source-separation possibility for this waste fraction but only to a smaller extent interested in using designated jars for FOG-collection distributed by landlords. Further investigations are needed to assess the impact from the collection on the sewage net in the multifamily buildings where the system has been introduced.