It was ten years ago when Kate Spencer, now a professor of environmental geochemistry at Queen Mary University, first strolled along the banks of the Thames and noticed rubbish peaking out from the undergrowth. The litter hadn’t been dropped on the ground, it was emerging from within it. Spurred into action by this disturbing sight, Spencer spent the next decade researching historic landfill sites (defined as any site no longer in active operation), in particular those built near the coast.
These old costal sites are common because transporting rubbish to the edges of the country, where it could be buried and forgotten about, was a popular move at the start of the 20th century when many landfill sites were first built. It was also deemed a sensible way to utilise saline land with poor agricultural value. According to Environment Agency statistics, there are now 1,264 historic landfill sites in England which are vulnerable to coastal erosion and flooding. The risk is that the material hidden within these pits ends up on beaches and in the water, a problem set to get worse if sea levels rise as predicted and as the UK’s coasts are battered by more frequent storm surges.
As Spencer’s walk ten years ago revealed, some of this buried waste is already reappearing. On the banks of the Thames Estuary in Essex, bits of rubbish can now be seen poking out from the exposed earth and littering the scrubby beaches. During the course of her research, Spencer has found car batteries, plastic packaging, discarded tights and items containing asbestos on beaches near old landfill sites.
It’s the latter that really concerns Spencer. When many of these sites were built, the regulations governing disposal of waste were much weaker than they are today. It means the rubbish emerging from the depths could contain toxic chemicals and other dangerous substances. ‘Sites weren’t lined, gases weren’t monitored and there was also no requirement to record what went in them,’ says Spencer. ‘If you go back to pre-1970s you have the potential for some really quite hazardous materials to have gone into these sites – such as asbestos.’
To determine the scale of the problem, Spencer and a team excavated rubbish from two landfill sites in Essex. The first, Hadleigh Marsh landfill, is a flood embankment built from the waste itself. The second, Leigh Marshes landfill, is a recreational area. At both sites you could take a walk and never know what you were treading on. The team had to enlist the help of a JCB digger to unearth the long-buried rubbish.
‘We dug big pits and then we removed a few tonnes of waste and brought it back to the lab,’ says Spencer. Once there, the team simulated flooding and erosion, which meant taking a bucket of waste, adding salt water and shaking it about. Several contaminants, including metals such as lead, leached into the water during this process. But though that sounds alarming, it isn’t Spencer’s biggest concern. She says that the plentiful waters of the estuary will probably dilute anything nasty. Instead, she is more worried about the solid waste itself and the potential impact it could have on marine life.
‘We’ve identified materials that people would have thought were completely inert, such as newspaper or textiles, and actually they were really contaminated,’ she explains. ‘That’s because they’ve been in a landfill site and as the waste has decomposed all the leachates have run through it. Absorbent materials have soaked everything up, so actually paper fibres and textile fibres are really contaminated. To organisms, a cellulose fibre or polyester fibre is indistinguishable from a plant fibre.’
A further concern is that much of the waste is plastic, with the potential to contribute to microplastic pollution if the land is ever flooded, not to mention the fact that beaches covered by rubbish are likely to suffer from reduced tourism.
In light of this research, the Environment Agency will now have to reconsider plans to purposefully flood certain areas of the Essex coast. Spencer says that the Agency had hoped to deliberately breach some coastal defences in order to restore and recreate the saltmarsh which once dominated the area and which is now recognised as an important ecosystem with the value to store carbon, sequester pollutants and naturally defend the coast.
Of course, the ideal solution would be to get rid of the old rubbish altogether, but unfortunately it’s not that simple. Because nobody knows exactly what’s in the ground, it would be complicated, dangerous and expensive to move the waste around the country to an incineration site or other facility. Instead, the most viable approach is to try and prevent the waste getting out, though it’s not a permanent solution. ‘The short-term fix is to go to sites that are already eroding and strengthen the sea defences,’ says Spencer. ‘But given that there are well over 1,200 sites that are potentially at risk in the UK – and around Europe there are nearly 10,000 sites at risk – these are short-term reactionary fixes. You’re kicking the can down the road. I think what we need to do is improve our technology for reusing and recycling the waste that’s there.’
Until this happens, and it’s unlikely to be soon, much of our old rubbish will remain underground, most of it out of sight, but no longer out of mind.
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