In defence of commingling

With all of the recent furore over commingled collections it seems to have been forgotten that there are several methods of collecting multiple materials from the kerbside and this whole situation has arisen from the historic need of local authorities to incentivise its residents to recycle more and more material.

If we go back to the 1990s when recycling rates were bumbling along below 10% and source separated collections were only really present in boroughs that could afford them, the whole focus was on providing least cost solutions. With the Landfill Directive and environmental legislation in the UK still some years away the only way to increase recycling rates was to look at innovative systems and methods.

West Sussex county council and Drinkwater Sabey set up a joint venture materials recycling facility (MRF), which supported by funding from the EU developed and set up the UKs first fully automatic plastic bottle sorting system. This enabled the collection authorities to collect separated paper but commingled bottles and cans. This process proved very successful and with the bulking of source separated glass provided a county MRF that handled 25,000 tonnes per annum at an operational cost of 8 per tonne.

In 1993 The Royal Borough of Kensington and Chelsea opened a MRF that took the process further by being the first authority to introduce kerbside commingled collections that included glass. The Royal Borough is two miles by three miles and is one of the most densely populated areas in Europe. They could not get their recycling rate above 6% and they saw this type of kerbside collection as a good way of increasing the rates. They moved to a twin bodied compaction vehicle with one third being for recycling and two thirds being for waste. The ultimate plan which they realised some years later was to change that where one third was waste and two thirds was recycling.

There was a huge amount of interest from inner city authorities for this type of collection as it just ticked so many boxes. The residents had a very simple system and recycling was made easy for them. In other neighbouring boroughs recycling was deemed to be too complicated as the residents had five different coloured sacks with each sack representing a different material type and each different material type was collected on a different day.

Today it is far too easy to criticise where we are without actually understanding how or why we have got here. It was not that many years ago that the Audit Commission recommended that local authorities adopted the twin wheeled bin system as the most effective method of total kerbside collection.

The main issue around this type of collection is the impact that glass has on the material. Most operators will insist that the glass is fully extracted but in reality once glass breaks the shards become air born and becomes imbedded in both the materials and the plant in general. The operational and maintenance cost of running a facility that processes glass is incredibly high. Equipment life spans are dramatically reduced and down time is greatly enhanced.

Local authorities must be allowed to decide for themselves which recycling system suits their residents and provides overall best value. The operators have a duty to produce a product that is acceptable to end users and regulators have a responsibility to ensure that it is done in an appropriate manner.

There is no one system fits all.