Coming Back To Haunt Us
Landfill: potent pollutant, or potential profit?
By Dave Young
However assiduously HIP’s readers sort their rubbish, some simply cannot currently be recycled and goes to incineration – or more likely landfill.
Brits have been dumping stuff into holes in the ground since Roman times, inadvertently providing a fascinating historical timeline for archaeologists. However, in the post war period the practice became much more problematic. Mass manufacturing created a throwaway society and an exponential increase in landfill (up to 7% a year) as new synthetic materials caused a (literal) sea-change in what was discarded. Petrochemical-based plastics and synthetic fibres that didn’t degrade, and electrical goods containing toxic trace metals were just some of the horrors.
Landfill became big business and gravel pit owners made a fortune, charging one set of customers for the aggregate and another to dump rubbish in the resulting hole – until science began to detect polluted streams and methane gas.
Successive governments have legislated and the waste industry has become cleverer, lining the pits to prevent groundwater contamination, covering them with topsoil and landscaping, and monitoring emissions from the decay beneath, for example.
In recent years, increasing environmental awareness has led to a growth of recycling while the combination of land shortage and increased taxation has actively discouraged dumping; a situation apparently under control, except, as new investigations worryingly reveal, it isn’t.
For a start the National Audit Office (National recycling obligations, July 2018) reports over half of packaging reported as recycled is sent abroad. Consequently we’ve little clue whether the recyclable waste is getting turned into new products, buried in landfill or burned. In short, we’re just dumping it elsewhere.
Worse, a succession of governments left the precise details of recycling to local and regional authorities, the better to distance themselves from any subsequent revelations of pollution and bad practice. With no overall coherent strategy, what can and can’t be recycled varies widely – a postcode lottery. A lack of consistent standards and fluctuating prices means that there’s no reliable supply of raw materials to industries that can make use of recycled goods.
Although an illusion of success has been created by the UK’s system for recycling packaging, the NAO report finds the government has ignored underlying waste disposal problems and firms may be over-stating the amount they’re recycling. We’re ducking or exporting the problem, and either way, a lot of potentially recyclable rubbish is still going into the ground.
A simultaneously fascinating and disturbing BBC 4 documentary, ‘The Secret Life of Landfill: A Rubbish History’, recently demonstrated how the nature of our waste is changing, and the environmentally threatening challenges this poses. By digging deep into a number of old rubbish tips the programme unearthed some disturbing findings.
At an 1890s site, Victorian bottles and jars are all that remains of domestic rubbish. In contrast, at a 196Os coastal dump eroded by time and tide, asbestos and carcinogenic batteries are being released into the sea.
The latter finding echoes recent research by Queen Mary College, University of London. While the term ‘landfill’ usually implies filling a hole there are many ‘land-raising’ sites where waste was tipped on the ground and covered: Pebsham playing fields, site of the abortive Hastings aerodrome, is a local example. Many such sites adjacent to rivers or floodplains and below sea level have been used for land reclamation.
“Since climate change is predicted to cause more frequent and intense storm events … landfill sites and other areas of contaminated land … are at risk of flooding and/or erosion. In some locations flood defences were constructed using landfill waste. These areas are now very vulnerable and there is potential for diffuse pollution to be released,” reports the Queen Mary geography department.
When excavating a tip from the 1980s, the BBC4 documentary team discovered the very act of sealing it to prevent leakage had disrupted the usual process of decomposition; children’s clothes made of synthetic fibres and even newspapers were fully intact after 35 years in the ground. In an anaerobic environment expected rates of decay slow dramatically.
On other sites, despite preventative works, leaking pollutions (leachate) had to be contained to prevent groundwater contamination.
Fortunately there is some brighter news. Leachate can be cleaned by creating reed beds as natural filters, with the added benefit of providing wildlife habitat.
Methane collection can produce electricity and fuel local heating schemes.
Scientists have recently identified an enzyme able to ‘digest’ certain plastics.
Most astounding of all, plans are now being drawn up in several countries to mine landfill.
Consider this, to produce a gram of gold requires either a ton of gold ore or 40 discarded smartphones. So landfill sites might be a handy source of the sort of rare-earth metals essential to electronic goods manufacture – and the cause of innumerable conflicts in the Congo, their principal and finite source.
A phone may contain up to 75 different rare elements, and there are, says Dr Zoe Laughlin in the BBC programme, more mobiles on earth than people, each phone having an average lifespan of two years.
Where once we buried our rubbish, it may soon be economically worthwhile to excavate it. Don’t get too complacent though; remember what happened to Brian Aldridge in the Archers…
How long rubbish takes to breakdown
1. Glass bottles: one million years
2. Disposable nappies: 450 years
3. Plastic bottles: 450 years
4. Plastic bags: 200–500 years
5. Aluminium cans: 80–200 years
6. Rubber-soled shoes: 50–80 years
7. Tin cans: 50 years
8. Clothing: up to 40 years
9. Plastic film: clingfilm, magazine wrappers, crisp packets, 20–30 years
10. Paper coffee cups: 20 years
(Source: BBC Science Focus)
• East Sussex County Council currently monitors 17 former landfill sites for gas (including the Hasting, South Saxon former landfill tip in Filsham Valley).
• Pebsham landfill site in St Leonards was the last active dump in the county. The last section closed in November 2013 and is being restored.
• Landfill waste is currently sent elsewhere, including West Sussex.
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