Plastic action – tackling the domestic waste stream

Packaging Professional magazine
,
17 Jul 2009
Packaged fruit

A WRAP study into the costs of collecting and recycling household plastic packaging aims to help local authorities meet public demand. Phillip Ward, Director of Local Government Services for WRAP, describes why the research was conducted and highlights key findings.

The increase in recycling rates achieved in the UK for a growing range of materials has drawn public attention to elements of the domestic waste bin that are not widely recyclable. Much of the plastic packaging thrown away by households – described collectively as ‘household plastic packaging’ – falls into this category, and pressure is growing for more of these materials to be recovered and reused.

The UK’s Waste & Resources Action Programme (WRAP) defines household plastic packaging as all plastic bottles, non-bottle plastic packaging, and rigid and flexible items of various polymer types and colours recovered from the domestic waste stream. This includes films, tubs, pots and trays of the type typically used to package food.

Plastics account for just over 11% of kerbside waste by weight, with around two-thirds comprising household plastic packaging. Not all of this material ends up in landfill. Around 86% of UK local authorities offer plastic bottle collection services and, as a result, the recycling rate for plastic bottles stands at 34%, and is continuing to grow. However, recycling options for the other elements of household plastic packaging, especially films and rigid containers, are not as developed, and the capacity for recovering such items is limited.

Public opinion is not the only factor driving the demand for greater recovery and reuse of packaging plastics. Increasing disposal costs, waste management legislation and climate change policy have made the issue a priority for local authorities. As a result, many have begun to consider strategies for extending their existing collection services to include more household plastic packaging. There are concerns about the cost and practicality of this, which WRAP investigated in a study completed this year, considering the financial costs of collecting mixed plastics packaging.

Building a new model

The research has used models to generate indicative costs for collecting more household plastic packaging for recycling. Because of wide variations in circumstances between local authorities, and the recycling services they offer, WRAP modelled a number of different collection systems in operation for a single, specially constructed, notional local authority. The model had 50,000 households, 48,000 of which were on the authority’s collections service. For the purposes of the study, the households were divided into different housing types, with logistical assumptions applied to each. Wherever possible, key input assumptions were based on operational data and have been discussed with industry stakeholders.

An important consideration for researchers were the assumed values used for gate fees and the income generated from the sale of collected materials, both of which can vary widely between areas and over time. In order to give a long-term view of material prices, wherever possible, materials values were based on averages generated from the Market Pricing Report and other data collected by WRAP’s economists over the last two years.

Based on these assumptions, researchers established indicative baseline costs by modelling the collection of a range of recyclate, including plastic bottles, using four collection methods – co-mingled, two stream, kerbside sort and bring systems. Each method was modelled for rigid plastic packaging and, separately, rigid plastic packaging with plastic films, in addition to a range of recyclate. The differences in costs between these extended collections and the baseline models provided indicative incremental costs for collecting more household plastic packaging from the municipal waste stream.

Costly business

The results show that the costs of collecting rigid plastic packaging using kerbside sort systems, excluding any savings from avoided disposal costs, are £239-268/t for collections on a fortnightly basis, and £287-334/t for collections on a weekly basis. For collecting plastic film using kerbside sort systems, costs are a further £44-217/t. Using two stream systems, the indicative incremental costs for collecting rigid plastics, again excluding savings from avoided disposal costs, are £74-104/t and £150-217/t for plastic films.

The indicative incremental costs of collecting mixed plastic packaging using co-mingled collection systems are £130-149/t for rigid plastic packaging, and £206-232/t for plastic film. The indicative costs for collecting mixed plastic packaging using bring schemes are £32-220/t for rigid plastic packaging and a further £42-150/t for plastic film.

The actual cost that will be incurred by local authorities adding household packaging plastics to their collections will vary. These will depend on how collections are funded, the existing services provided by authorities, and the additional resources required for services to be expanded. For some local authorities these materials could be added for little additional cost, whereas for others the expense could be significant. This is one reason why WRAP does not suggest that all local authorities introduce these collections.

The report gives local authorities a good indication of the incremental costs they may face if they decide to recover more plastic packaging from the municipal waste stream. The findings allow them to assess the viability of extending their recycling systems, while giving a valuable insight into the cost implications of alternative methods. Ultimately, the study gives the recycling supply chain the advice and confidence it needs to ensure that more household plastic packaging is collected and recycled in the future.

Further information: WRAP