Making Sense of Mole Valley’s Glass Recycling Policy
Background
Before the Leatherhead Material Recovery Facility (MRF) was modified last year to be able to sort glass, Mole Valley residents had to recycle glass by taking it to bottle banks. MVDC says that only 60% of the available glass was recycled in this way, the remaining 40% going to landfill via the black bins. From January 2008, the Leatherhead MRF has been able to sort glass, and residents have been able to put glass bottles in the green bin along with paper, plastic and metals. The MRF sorts the glass from the other components, producing a crushed glass product that is used within Surrey as aggregate, replacing crushed stones. However the glass industry prefers to have glass collected separate from other wastes so that it can be used to make new glass. Jean Pearson, Leader of MVDC, has defended Mole Valley’s new practice, quoting the following benefits:
· boosts Mole Valley’s recycling rate
· enables more residents to recycle glass (not everyone could take bottles to bottle banks)
· saves car fuel as journeys to bottle banks are eliminated
· mixing glass with other wastes is a beneficial method of recycling recognised by policy-makers throughout the country· reduces the need for aggregates quarries.
So which is best – separate or mixed glass collection?
The benefits of separate glass collection
Glass making requires three main raw materials – sand, soda ash and limestone – and a temperature of around 1700 deg C. It therefore uses very large quantities of heat energy, in addition to the energy needed to quarry and transport the raw materials to the glass works. The use of recycled glass as a raw material gives significant energy and cost savings. The recycled glass has to be re-melted which requires heat, but the amount is significantly less than that needed when working from the raw materials. However the recycled glass has to have a high level of purity and to have been sorted by colour. The national network of bottle banks was established to provide recycled glass of the required quality.
If glass has been mixed with other waste, it cannot be used for re-melting and is usually sold much cheaper for use as aggregate. Friends of the Earth (Ref 1) says that there is no environmental benefit from using glass to make aggregate.
Mole Valley’s move is part of a growing trend for councils to improve their recycling rates by accepting glass in the green bin and then sorting the glass at a MRF. Some councils only collect mixed glass and cans however, and do not mix in waste paper like Mole Valley. This is probably because, not only does paper contaminate glass waste, but glass contaminates paper waste. Some paper mills will not handle recovered paper from MRFs, or paper that has been mixed with glass.
Green Mole Forum’s View
The benefits to a local council of collecting glass in the green bin seem pretty clear: it improves their recycling record which is an important target. This is spelt out by this quote from another local authority "We want to drive up recycling rates to more than 65%. Our current recycling and composting rate is 43%. Our landfill options are running out and like many other local authorities, we are moving towards improving recycling. Glass is very heavy and bulky so if we are judged on tonnages, glass will make a difference."
Jean Pearson’s defence of the Mole Valley glass collection policy does not seem very convincing to us.
The amount of glass collected from recycling has increased, but the environmental benefit of the recycled glass is much lower.
People no longer have to drive to bottle banks, but has MVDC any idea of the fuel saved and how this compares with the energy saved in glass making? In our experience most people used to combine a visit to the bottle bank with a journey for another purpose like shopping, and so the savings are probably less than first imagined.
We suspect that “Mixing glass with other wastes is a beneficial method of recycling recognised by policy-makers throughout the country” probably just means that other councils are doing this too. That does not make it right.Using crushed glass as aggregate reduces the need for aggregate quarries, but recycling glass into glass making reduces the need for sand, soda ash and limestone. We suspect the latter savings are larger.Is MVDC aware that the recycled paper has a lower value once it is has been mixed with glass?
We therefore intend to put these points to MVDC. If they cannot justify their policy better than they have to date, we feel that they should admit their mistake and go back to bottle banks.
Further information
1. Friends of the Earth Recycling Briefing: http://www.foe.co.uk/resource/briefings/recycling_collections.pdf
2. Waste Management News article on glass collection: http://www.letsrecycle.com/do/ecco.py/view_item?listid=37&listcatid=217&listitemid=9222