Aberdeen City Council (ACC) is to move from dual-stream to fully co-mingled collections ‘over the next few years’, it has been announced.

Releasing the 'Aberdeen City Waste Strategy 2014-2025' yesterday (6 May), the council outlined that moving to a fully co-mingled recycling service will ‘significantly increase [its] recycling rates and… drastically reduce [its] landfill costs’ as it will ‘allow residents to put all recyclable materials into one container’.

However, in somewhat confusing language, the new strategy states that ACC has implemented a target of recycling 50 per cent of household waste through ‘source separation’ by 2020 (rising to 56 per cent in 2025). Despite this, a spokesperson for the council told Resource that this is ‘outdated’ language that distinguishes recycling collections as separate from mixed waste, rather than referring to the source segregation of dry recyclables.

Reasons behind co-mingling approach

ACC currently operates a fortnightly, dual-stream kerbside collection of dry recycling to approximately 70 per cent of households in the city. Those eligible for the service use a box to recycle glass bottles and jars, food and drinks cans, foil, aerosols and plastic bottles, and a bag to recycle paper and cardboard.

However, the council has said that the box and bag system is ‘no longer fit for purpose’, and that ‘residents need more space in a container that is protected from the weather’. It is thus ‘envisaged’ that this service will be replaced city-wide ‘over the next few years’ by a wheeled bin service accommodating all the above dry recycling (including glass), as well as plastic containers and waxed food and drink cartons (Tetra Paks).

Despite the new Waste (Scotland) Regulations stating that local authorities should provide the occupier of every domestic property in their areas with ‘such receptacles as will enable the separate collection of dry recyclable waste from the property’, there is a caveat that states that co-mingled collections would only be permissible after 1 January 2014 if the authority ‘considers that the amount of material recycled from such waste in its area will not be significantly less, and the quality of the material recycled will not be significantly lower, than would be the case were the authority to comply’.

ACC told Resource that it believes co-mingling is the ‘only way to comply with the statutory obligation in the [regulations] to provide a recycling collection to all households (including the >50 per cent in the city living in flats or tenements)’, but acknowledged that it could have ‘challenges in meeting the quality element of the Scottish Government's approach’. However, it added that it believes that ‘by the application of the best available processing techniques, [it] can achieve both quality and quantity in recycling’.

New waste infrastructure

These processing techniques, such as mechanical and optical sorting, will be used in a new materials recovery facility (MRF) for sorting the co-mingled materials into the following streams for sale: paper; cardboard; tins; cans; and glass (by colour).

The MRF represents just one of several facilities that ACC intends to bring online to deal with its waste. Indeed, the council has committed £28 million for the development of its new infrastructure and recycling services.

Food waste collections will be extended through the city, with organic waste expected to be collected from all households by 2016. This material will then be sent to a new in-vessel composting (IVC) facility to produce fertiliser from organic waste.

ACC has also set itself the target of ‘eliminating waste growth’ by 2015, and landfilling no more than five per cent of household waste by 2025. This will reportedly be done through the roll out of its new co-mingled recycling and food waste collections, as well as by introducing reuse facilities at its household waste recycling centres (HWRC) – a pilot for which is scheduled to begin in 2015 – and building an entirely new HWRC in the ‘north of the city’.

All residual waste will be sent to a new refuse-derived fuel (RDF) facility until the council develops an energy-from-waste (EfW) facility in the area to recover heat and electricity from the waste.

It is yet to be seen if the RDF equipment will continue to be used to prepare waste for the EfW plant, with ACC stating that this will most likely be determined once it has a ‘clearer picture on how SEPA's thermal treatment guidelines are defined/applied’.

The council has said that it will also ‘develop partnerships to facilitate the expansion of the district heating facilities by 2025’.

ACC currently holds a waste contract with SITA UK Ltd until 2025, and it is thought likely that this company will be approached to develop all of the new infrastructure, except for the EfW plant.

A decision on whether this will be a new ACC procurement or developed in partnership with other local authorities will be made once a site for the EfW facility has been identified at the end of 2014/early 2015.

‘Providing long-term social, economic and environmental benefits’

Aberdeen City Council Housing and Environment Convener Councillor Neil Cooney said: "All of the materials in our waste containers can offer significant value to our homes and our businesses; we recognise the opportunities available to us when we recover these resources for our benefits – moving from a history of costly and damaging landfill to a future of sustainable resources and energy.

"Implementing the proposals within the Waste Strategy will make Aberdeen a zero waste [to landfill] city, providing long-term social, economic and environmental benefits to us all.

"The themes outlined in this strategy – and the improvements they will deliver – are the right choice for our residents, our schools and our business community, allowing Aberdeen to thrive and be an example to other local authorities."

Read the 'Aberdeen City Waste Strategy 2014-2025'.