Why contaminants can’t be run of the mill

Increasing numbers of bales are being rejected at paper mills due to contamination levels. Tim Price explores the delicate balancing act of driving up recycling levels while maintaining quality

There is much debate at the moment around co-mingled versus source segregated for kerbside recycling collections. DS Smith Recycling (formerly Severnside Recycling) handles around 1.7M tonnes of fibre each year, but increasing levels of contaminates are causing issues further down the supply chain.

Recyclers will argue that receiving source-segregated material is the ideal as it is cleaner and contains the least amount of contaminants. This also has a positive impact on the carbon footprint of the recycling operation as it means less secondary separation and reprocessing is required. However many argue that co-mingled collections get higher recycling rates.

This is where the difficulty comes in and as an industry we need to weigh up what’s most important in the long term – high recycling rates or quality material. Lower quality material runs increased risks of greater quantities ending up in landfill in the worst case, whilst pursuing higher quality material may lead to reduced recycling scheme participation.

Granted, this is a difficult debate, but it is one that is becoming increasingly necessary. The level of contamination coming through in paper bales that have come from co-mingled sources is increasing the number of bales that are rejected on arrival at the paper mill. Paper is a very different material to steel or plastic for instance, both of which can be more easily collected for recycling with other materials.

Paper, however, can be severely damaged through co-mingling – if another material is placed with the paper that has not been dried or cleaned correctly, for example. Industry best practice is to keep materials as clean as possible as far down the recycling process as possible. We encourage local authorities to find ways to keep paper and packaging recycling separate from other materials.

However, different local authority policies are seeing extremes – for instance councils recently received damning publicity from the TaxPayers’ Alliance which focused on the nine bins that one local authority asked its residents to use for recycling segregation. To achieve the best balance, identifying the materials that are best suited for co-mingling and those with potential to have a negative impact on paper quality will mean not only a robust recycling rate, but also good quality recyclable material – a win win situation.

The public understands why it is asked to recycle and does so in the good faith that the materials they take time to clean and segregate are used in the best possible – and highest value – applications. Demand for higher quality recyclate is growing, for instance, the UK has exported much of the lower grade paper to China, but now Chinese quality demands are rising in line with more stringent requirements from its end customers.

Therefore, to keep reducing the 3M tonnes of paper waste that ends up in landfill in the UK each year, it is important that we find a solution that marries the ease, cost-effectiveness, quality and manufacturing requirements required by the supply chain.

The impact of contamination, from the co-mingling of materials that do not sit well together, can be costly at the end of the supply chain – for example glass can cause significant damage to a paper mill’s processes and any rejected bales need to be resorted or as a last resort landfilled, incurring gate fees and tax.

All of which is contrary to what waste producers and recyclers set out to achieve in the first place. To stop contamination becoming a long-term issue to recyclers there is a need for greater consistency in waste management practices across the UK and greater understanding of the impact comingling can have on paper. It’s not practical for every material to be separated – it’s not necessary and would certainly have a detrimental impact on participation.

However, to ensure demands for high quality recyclate are met requires greater understanding among local authority policy-makers of the impact certain systems have. As well as reviewing policy, pursuing quality recyclate sorting technology needs to be considered.

More development is required to enable even cleaner waste streams and technology must operate to best practice at all levels – from kerbside collection policies and processes through to MRF separation to ensure that contamination levels are minimised and the increase in bales being rejected is reduced.

It’s certainly a balancing act, and there is no easy solution, but from a policy point of view the UK needs to be looking far into the future and have the foundations in place that will ensure we continue to grow our recycling rates, but not to the detriment of quality.

Tim Price is national commercial manager at DS Smith Recycling

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie