Waste management systems and reuse of materials

A circular and efficient resource management system is being developed in Stockholm Royal Seaport. The goal is to reduce resource consumption, increase resource reuse, with as little as possible going to landfill, contributing to decreased climate impact and circular economy.

Integrated Waste Management Solution

The basis for waste management is the waste hierarchy, which primarily involves preventing the generation of waste, followed by reuse, and then material and energy recovery, and lastly disposing of waste. Swedish municipalities are good at collecting, sorting, and recycling waste, with only small amounts going to landfill. However, the trend in Stockholm shows that the volume of waste is increasing, and the collection of food waste is too low. Reducing both the amount of waste and viewing waste as a resource is a priority to conserve virgin materials and resources. Stockholm Royal Seaport has adopted a holistic waste management approach to simplify the waste sorting process.

Making it easy to do the right thing

One of the challenges identified early on in the project was the collection of food waste. Experience from the development of Hammarby Sjöstad, (the first sustainable urban district in Stockholm), showed that vacuum systems were not the most efficient way to collect food waste, it was therefore decided that food waste grinders in kitchens would be tested at scale. To date, 3,000 food waste grinders have been installed connected to the wastewater system, which means that the organic waste is taken to the Henriksdal wastewater treatment plant and contributes to increased biogas generation. Separate collection of food waste is planned for future stages.

The vacuum waste collection system takes care of three fractions: newspapers, plastic packaging, and . All properties are connected to the vacuum waste collection systems by waste chutes in or in proximity to the entrances. Waste is transported via pipes in the ground to large collection containers in a cavern collection point. The purity of plastic packaging was 99 per cent in a random check in 2021.

There are no recycling stations in street environments. Instead, there are recycling rooms close to the entrances of properties for fractions that it is not possible to dispose of in the vacuum waste management system or food waste grinders.

Hazardous waste can be dropped off at Stockholm Royal Seaport's automated collection station, which is open 24 hours a day, using text message or a QR code. When it opened in 2012, the station was the first of its kind in the world. There are now five in Stockholm.

Pop-up Reuse Centre reduces bulky waste

The Pop-up Reuse Centre is a mobile reuse station developed in Stockholm Royal Seaport in 2015 through an innovation procurement. Books, household items, and other items that others can benefit from or enjoy are collected and given a new owner directly or go to a reuse entrepreneur. The Pop-up Reuse Centre has since been further developed by Stockholm Vatten och Avfall, and has become part of their regular operations, which has contributed to 124 tonnes of Stockholm's used belongings going to reuse. The innovation procurement also inspired permanent reuse centres in the Skärholmen and Järva districts of Stockholm, were visitors can donate items for reuse and recycling, use wood, textile, and bike workshops, and find bargains in the bargain corner.

Prevent the creation of construction waste

One third of all waste generated in Sweden is construction and demolition waste. To highlight the importance of preventing and reducing the amount of construction waste, developers must reduce construction waste. To facilitate sorting, handling and follow-up of construction waste, all developers are affiliated with the , which supports the efficient management of construction waste.

So far, no developer has met the construction waste requirement, with an average of 47 kg/m². This is partly because developers did not work proactively enough to prevent and reduce waste, and partly due to shortcomings in quality assurance during the construction phase.

For public open spaces, construction waste is sorted at source and the proportion of construction waste that goes to landfills is minimised. The largest proportion goes to energy and material recycling. As some construction waste consists of usable and surplus material, the possibility of accepting these materials at the Construction Consolidation Centre is being investigated.

Water and wastewater flows

Heat, biogas and phosphorus-rich wastewater sludge are already extracted at Henriksdal wastewater treatment plant. By separating wastewater flows and collecting in separate systems already inside the properties, resources such as water, energy and plant nutrients can be managed more efficiently. More waste heat, water and nutrients can then be recycled, and more biogas can be produced.

Source-separating wastewater systems have been investigated since 2011. The MACRO innovation project was launched in 2015 and since then, in various project phases in close collaboration with Stockholm Vatten och Avfall, investigated the conditions for source-separating wastewater systems for Värtahamnen and Loudden.

are installed in all kitchens and the waste is sent via the wastewater system to the Henriksdal wastewater treatment plant, where it contributes to increased biogas production. Eventually, ground food waste will be collected into a separate system. A pilot project involving 400 apartments in Kolkajen will also be conducted. Food waste will be taken to tanks in the vacuum waste system terminal. From there, it will be transported by truck to Högdalen for biogas production.

Key events in 2022

• Pop-up Reuse was in Stockholm Royal Seaport for two weekends and was visited by 8,630 people. 17,430 objects found new owners, 10.7 tonnes of material were reused, and 2.9 tonnes of bulky waste were collected, of which 2.2 tonnes were electronics and 0.7 tonnes were hazardous waste.
• In 2022, residual waste in the area decreased by 12% to 91 kg per person and year compared to 2021, when it was 104kg per person and year. The newspaper fraction decreased by 9% and plastic by 15% compared to 2021.
• A planning manual and guidelines and Source-separating wastewater systems have been developed as part of the MACRO project.
• A study visit to Hamburg, Germany was held with participants from the City Development Administration and Stockholm Vatten och Avfall to learn more about source-separating wastewater systems.