Oslo takes an integrated approach to treat waste into circular bio-resources
Oslo owns a biogas plant, transforming food waste into biogas, which is used as fuel by buses and garbage collection trucks in the city. Biofertilisers are also produced at the plant and used by farmers to produce food. This plant is the largest biogas plant in Norway with a capacity for 50,000 tons of biological substances.
Today, citizens in Oslo source separate 46% of their food waste in green bags. Likewise, the city’s recycling stations collected 15,300 tons - 27 kg per person - of garden waste in the same year. This waste was then composted and returned to citizens as soil so they could use it in their gardens.
Oslo aims to utilise the bio-resources from its municipal sewage system by sending the sludge to farmers for their agricultural activities. To ensure high quality sludge content, Oslo actively works to reduce the inflow of wastewater containing micro-pollutants to the municipal sewage network.
Changing citizens’ behaviours remains a challenge, specifically correctly separating their household waste. The bulk of food waste - 64% - is not source separated by citizens. In turn, the unseparated waste can only be used for energy recovery purposes.
- In 2016, 40% of household waste was either reused or recycled in Oslo, and only 3% ended in landfills.
- Liquid fertilisers used by local farmers reduce the demand for mineral fertilisers.
- Compost and soil qualities from composting garden waste reduce the use of other soil and compost resources based on peat.
- It is important to have a good dialogue with the future users when developing new products from waste resources. Oslo’s experience was dependent on having a good and constant dialogue with farmers, professional gardeners and the public transport company to produce a product that meets important quality requirements.
- The citizens deliver garden waste and buy soil products directly at the city’s recycling stations.