The findings were published in a study entitled ‘Contamination in source-separated municipal and business recyclate in the UK 2013’, which was launched by Zero Waste Scotland and supported by the Scottish Government.

Zero Waste Scotland (ZWS) was asked by the Scottish Government to manage a
UK-wide compositional analysis programme focused on determining the typical quality of five key source-separated recyclates – plastic, glass, metals, paper and card.

The aim of the project was to determine within “reasonable bounds of confidence” the typical levels of contamination in dry recyclate separately collected from households by local authorities and from the commercial and industrial sector by local authorities, reprocessors or third-party waste management companies.

A total of 225 business recyclate samples were taken across 18 sites; the six recyclate streams sampled were paper/card (paper; card; mixed paper & card), mixed glass, metals and plastics.

Overall, 860 municipal recyclate samples were collected from 59 sites; the ten recyclate streams sampled were paper/card (paper; card; mixed paper & card), glass (clear; green; brown; mixed brown and green; mixed glass), metals and plastics.

Contamination levels in source-separated business recyclate were found to be generally low, although the report states caution should be exercised in using these figures due to the low sample size obtained. The reported highlighted that the metals (median of 3.3%) stream was the most heavily contaminated followed by the paper (3.3%) and plastics (2.5%) streams.

Contamination levels in source-separated municipal recyclate were also found to be generally low. The metals (median of 6.2%) recyclate stream was the most heavily contaminated, followed by card (4.1%), plastics (2.9%) and brown glass (2.7%).

Although contamination was found to be “generally low” in source-separated recyclate streams, improvements can still be made, according to the ZWS study.

The report recommends that further efforts should be made to educate waste producers – both householders and businesses.

Speaking about the report, Zero Waste Scotland director Iain Gulland said: “Poor quality of material has long been regarded as a key issue for the resource industry, with contamination playing a major part in this. To date we haven’t had any robust data on this, so it’s great to be able to address this gap.

“Harnessing the maximum value from materials we collect for recycling is vital to achieving our zero waste goals and in helping us to move towards realising the environmental and economic benefits of becoming a more circular economy.”

SEPA principal policy officer Gary Walker said: “We welcome the results of this study into material quality in separate collection systems. Waste producers and waste service providers have a legal duty to ensure that the quality of material collected in co-mingled collection systems is not significantly less than that which can be achieved in separate collection systems.”

Project Steering Group member and Resource Association member Peter Seggie added: “The report itself summarises: ‘contamination levels in source-separated municipal recyclate were generally low’.

“This chimes with the approach maintained by the Association that, even recognising that materials come from all kinds of collections, our members still generally prefer source-separated materials as they have tended to produce consistently better quality feedstock for UK reprocessors.”

Liz Gyekye

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