Stretching from Lyme Regis towards Charmouth, East Cliff beach is a hotspot for fossil hunters scouring the shore for spiral-shaped ammonites or the glint of fool’s gold. As the 50-metre-high cliff slowly retreats and collapses into the sea, more rocks containing prehistoric fossils are exposed along Dorset’s Jurassic Coast.
But take a closer look and the cliff edge reveals more sinister deposits. Plastic, metal and concrete poke out from the soil and are strewn along the beach. With every storm and tide, smaller items of waste and toxic contaminants are washed out to sea.
This cliff marks the edge of an old landfill site called Spittles Lane. Used as a tip until 1978, it contains various metals including lead, asbestos, plastics and chemical contaminants. It is prone to landslides now.
In 2008, a 400-metre stretch of cliff collapsed, releasing waste on to the beach below. Scientists at Southampton University expect that the rest of this landfill will be eroded and collapse into the sea within the next century. They estimate that up to 6,000 cubic meters of waste have gone already and that Spittles Lane still contains as much as 42,000 cubic meters more.
This landfill, within a Unesco world heritage site, operates under a policy of “no active intervention”, meaning there is no investment against erosion because any potential chemical pollution is considered to be relatively diluted.
The council removes big pieces of solid waste, including asbestos, from the beach at regular intervals, but leaves smaller items and any toxic chemicals to be washed away.
Historically, choosing coastal locations for landfills was a conscious management decision, says Kate Spencer, professor of environmental geochemistry at Queen Mary University of London. She calculates that in England alone, more than 1,200 out of 20,000 landfills are on the coast.
“Older sites weren’t built to isolate pollution from the environment. They were engineered to allow any toxic chemical pollution or sewage to dilute and disperse. It’s how we’ve abused our estuaries and seas for centuries.
“Unless we defend them to the hilt, they are at risk of either flooding or erosion,” says Spencer, who has studied coastal landfills for 10 years.
This isn’t just a problem in England. “These landfills are a global problem on a geological timescale and now that we’re likely to see significant coastal change or floods, this stuff is much more likely to be released,” says Robert Nicholls, professor of coastal engineering at Southampton University.
Across Europe, it is estimated that there are between 350,000 and 500,000 landfills, 90% of which predate modern waste-control legislation requiring landfills to be lined and capped. Significant numbers of these older landfills are in coastal areas or floodplains.
In the US, more than 800 coastal “superfund” sites, which store toxic waste and include municipal landfills, are at risk of being flooded in the next two decades as the climate crisis raises sea levels. Landfills in developing countries such as Bangladesh and India are often located on low-lying flood plains.
Catastrophic climate events are already triggering large-scale releases of waste. In the US, 13 toxic waste sites in Texas were flooded during Hurricane Harvey in 2017. The failure of the Fox River historic landfill in New Zealand during a storm in 2019 polluted approximately 60 miles (100km) of coastline.
“We need to focus on adaptation all around our coastline because sea-level rise and coastal erosion are inevitable,” says Spencer.
One option is to let nature take its course as the coast erodes and landfills crumble into the sea. But, depending on the location and site contents, this could be risky to human health and marine life.
Another is to build substantial coastal defenses to protect the landfill and stabilize the slopes, but this is complex, expensive and not always possible if the coastline is protected by conservation status. Coastal landfills could be excavated and moved to a more secure facility inland, but costs are likely to be prohibitive.
Alternatively, some form of on-site processing could remove the most toxic elements, but to do this, more needs to be known about which materials and components are most hazardous. Spencer and Nicholls believe that landfills can be seen as a resource by extracting valuable precious metals, such as lithium and iron, or plastics that could be reused or recycled.
Landfill mining could raise enough funds to deal effectively with remaining contaminants, says Spencer, but there is debate about whether the economics could ever stack up.
It is not feasible to clean up every single site, said Nicholls. The best way to manage coastal landfills globally, he says, is to create an evidence-based system to rank them according to the level of risk.
“A lot of material in landfills probably isn’t terribly harmful once in the sea, but some really is. We don’t have a methodology to make that rational decision and we need to tackle the worst ones first,” he says.
Figuring out what chemicals are in landfills will also improve understanding of the potential damage they are causing and who is liable for that damage, says Spencer. “As with any pollution, identifying the source is challenging, especially when multiple diffuse sources exist, but until you do that, no one will take responsibility and pay to fix it,” she says.
Nicholls hopes that developing the tools to carry out better assessments of coastal landfills in the UK will have far-reaching consequences. “We could help solve our problems and then export what we learn and help solve the world’s problems,” he says, “because this issue is universal.”