Alternative Ways to Treat Non-Recyclable Waste

We’ve thoroughly considered the alternatives for dealing with the volume of household waste produced by north London’s residents – which represents around three percent of the UK’s total.

Where prevention is not possible, and in order of priority, waste materials should be reused, recycled, or recovered, including being used as a source of energy. The aim of the Energy Recovery Facility is to move waste up the waste hierarchy so that instead of simply disposing waste into landfill, its energy can be recovered.

Following wide-reaching public consultation with residents and engaging key industry stakeholders about the scheme, our technical specialists Ramboll carried out an extensive alternatives assessment. The assessment determined that replacing the existing energy from waste plant at Edmonton EcoPark is the most environmentally responsible way to deal with the challenge of north London’s non-recyclable waste in the future.

None of the alternatives provide a suitable or sustainable solution for the volumes of waste that need to be treated at Edmonton EcoPark. There are major limitations to each of the alternatives, all of which were carefully considered before energy recovery was determined to be the best option.

The alternative methods that were considered, and the reasons they were rejected, are summarised below.

Landfill. To protect our environment for future generations, it’s vital that we prevent landfill use in the future. Landfill would both cost more for north Londoners and would be worse for the environment, generating the highly damaging greenhouse gas methane, it would also cost more for north Londoners. Compared to landfill, our Project will save up to 215,000 tonnes of CO2 every year under 2019 assessments.
Making use of third-party energy from waste facilities where capacity can be found. This is not a long-term solution and would require transporting waste from north London to other plants, increasing bin lorry journeys, adding to London’s heavy road vehicle traffic and increasing the carbon impact of north London’s waste. It would also cost significantly more, with an estimated cost of £20 million more per year compared to building the new ERF.
Advanced thermal heating (pyrolysis and gasification). This option involves the decomposition of waste at high temperatures. It is still unproven at the scale required to treat north London’s non-recyclable waste in the future. Only smaller capacity plants are in operation, and, even at this small scale, there have been several issues with existing plants.
Mechanical biological treatment (MBT). MBT uses mechanical and biological processes to separate and sort waste. It is not a complete solution for disposing of non-recyclable waste, it is just a step before burning it. MBT produces a fuel which must still be disposed of. It is neither proven nor used at scale in the UK, and to treat the volumes of waste in north London we would need two processing plants plus an energy from waste facility.
Anaerobic digestion and composting. This method is only suitable for food or organic waste when it is collected separately. We currently use this for treating food waste, but it is not a solution for treating non-recyclable waste.
Materials recycling facilities: The NLHPP will provide capacity to treat the recyclable and non-recyclable waste for north London. Delivering flagship recycling facilities, including a brand-new public Reuse and Recycling Centre and a new Resource Recovery Facility, are an important part of this strategy.
Post-separation to extract plastics: This method has not been proven at the scale we need. Post-separation has been used in places with different waste compositions to north London, where plastics are disposed of with household waste. This means it is necessary to extract the recyclable plastics and the potential recovery rate from household waste is also higher due to not having separate recycling collections, as we do in north London.

Read the full alternatives assessment report.