Sewage sludge containing human waste from the Netherlands has been passed for import to the UK, to be used on farmland as fertiliser, despite concerns over the safety of its use.
Spreading the sludge on farmland is banned in the Netherlands, where incineration is preferred, but allowed in the UK. Dutch water authorities are eyeing the UK as a possible destination for their sewage, after problems at an Amsterdam incineration company left them lacking disposal options.
A permit for the shipment of 27,500 tonnes of municipal sewage sludge was issued in February by the UK’s Environment Agency, according to a document obtained under the Freedom of Information Act by Greenpeace’s Unearthed investigative unit and seen by the Guardian.
The sludge is listed as coming from the Amstel, Gooi and Vecht water board but the identity of the recipient in the UK has been redacted. The permit is valid until February.
It is legal in the UK to use sewage sludge on farmland but it must be first treated and then applied under strict regulations. However, the Environment Agency has raised concerns that the regulations are not always followed.
In November 2017, the Environment Agency had a report drawn up that listed potential problems for human health from using sewage on farmland, including the presence of pathogens such as E coli and salmonella, persistent organic pollutants, heavy metals and microplastics.
It also found the supply chain handling sewage from its origins to its destination on fields was “convoluted”, which raised the possibility of abuse of the regulations and contamination of farmland.
Alistair Boxall, a professor in environmental science at the University of York, said Dutch sewage was unlikely to be any worse than that from the UK, but the government was not doing enough to ensure that sewage spread on fields was safe.
“The government is doing very little to understand what harm sludge could be doing to humans – they don’t have the data,” he said. “If we can ensure that you don’t have harmful contaminants, then [using sewage] is a good thing. But at the moment really we don’t know whether some of the things in there are safe or not.”
A further concern is that using sewage as fertiliser could foster the growth of superbugs, which are resistant to antibiotics.
Coilin Nunan, a scientific adviser at the Alliance to Save Our Antibiotics, said: “Human sewage can be an environmental source of antibiotic-resistant bacteria and of antibiotic residues. Wastewater treatment plants can reduce but not eliminate all the antibiotics and resistant bacteria.
“If human sewage is spread on land growing food for human consumption, the possibility of antibiotic resistance being spread to people is greater than if it is spread on land producing other types of crops.”
Dr David Spurgeon, an ecotoxicological researcher at the UK Centre for Ecology and Hydrology, said there were benefits to using sewage on farmland: “It is a way of returning nutrients to soil, which means we can reduce the use of mineral fertilisers, it helps build soil structure which helps avoid soil erosion, and it returns carbon to the soil which can help with meeting carbon reduction targets.”
Sewage treatment, though effective in removing many chemicals, was “not perfect, and there are some chemicals that can survive treatment” and other contaminants and pathogens that could get into the food chain, he added.
“Sludge to land does need some management and that is why there is a code of practice to try to limit any issues,” Spurgeon said.
John Sauven, the executive director of Greenpeace UK, said the government’s oversight was not working, and pointed to cases in recent years where the rules had been violated, and concerns raised in the Environment Agency’s 2017 report over enforcement.
Sauven said: “The UK’s sewage sludge supply chains are already full of shady middlemen and waste brokers getting their hands dirty exploiting its opacity and the resulting regulatory failings. This is why the sludge that is spread on to our farms and fields has become such a toxic cocktail of plastics, chemicals and bacteria.
“Add waste from the Netherlands into the mix and the risk of further contamination is only going to skyrocket. The Environment Agency really needs to get its own house in order before we allow the UK to become a dumping ground for other countries’ polluted sewage.”
A spokesperson for the Environment Agency said: “We take our responsibility to protect the environment very seriously and our new sludge strategy ensures farmers’ use of this fertiliser is based on the latest scientific data. While spreading waste can have beneficial impacts on the land when used as a substitute for manufactured fertilisers, we are clear this practice must not harm the environment.
“We will not hesitate to take enforcement action against those who fail to manage any risks appropriately – including prosecution in the most severe cases.”