Water companies “might well go bankrupt” if the burden of removing forever chemicals from UK waterways is solely placed on wastewater treatment works.
Instead, a panel of industry and academic experts has argued that banning forever chemicals is the only way to successfully remove them from the UK’s waterways.
Speaking at the Utility Week WWT’s Wastewater 2024 Conference, water company technical leads and academics agreed that banning substances would be more efficient and effective than the current plan of removing chemicals at treatment works.
So called forever chemicals – such as PFAS and PFOS – are found in everyday household products and are used widely in manufacturing and have been entering the water system from myriad sources for many decades, with research and treatment struggling to keep apace.
In 2022, the Environment Agency reported that every river in Britain was failing environmental quality standards (EQS) for chemicals. These were failing both upstream from treatment works and in the downstream effluent for at least one of these 148 standards.
The Chemicals investigation programme (CIP) overseen by UKWIR has spent £190 million since 2010 to understand where these chemicals are entering the waterbodies and whether they can effectively be treated out.
Analysis of data from 600 treatment sites showed that while certain pharmaceuticals and substances can effectively be removed, others can not.
Matt Hill, lead environmental advisor at Yorkshire Water, explained that traditional biological style treatments are more effective at removing PFOS than newer style treatments.
However, he warned that PFOS can only be removed effectively using “really expensive drinking water treatment processes” such as pressurised membrane filtration, with granular activated carbon, or ion exchange. These would be prohibitively expensive to apply to wastewater treatment, he added.
Eliminating ubiquitous, persistent, bioaccumulative and toxic substances (uPBTs) from the waterbodies would see the majority (93%) classified as good standard, Hill explained and advocated for a ban of harmful chemicals.
“We need to have those bans, we cannot remove PFOS to environmental quality standards through treatment,” Hill said and warned that even through treatment the chemicals were often redistributed to biosolids or another location rather than actually dealt with.
Bans, however effective, do take time for the results to be seen, Mark Craig, long term asset strategy lead at Severn Trent, said.
These substances are not all broken down in treatment processes with many not biodegrading, therefore, Craig said the current approach is “not getting rid of the problem, we’re just moving it”.
For Severn Trent’s largest treatment site at Minworth to pass the discharge EQS, a 97% removal rate of PFOS would be required, however with test sites upstream from the plant already failing these levels it cannot be achieved through treatment.
He said there could be “quick wins” by targeting the source of excess PFOS in trade effluent and treating this before it reaches the sewage plant.
Admittedly, that would be difficult but 200 cubic meters daily of trade effluent would be easier than 550 megalitres daily of discharge effluent from the wastewater treatment plant.
Government should ban substances that in small quantities cause whole rivers to fail EQS, Craig added.
“We need to get the chemicals at the point of entry to the sewer,” Craig said, “There might be viable treatments you can deploy to make progress on lowering EQS.
“Trying to get all sewage works down to the standards for EQSs through end of pipe treatment alone, while dealing with overflows and doing other things as well, we might well go bankrupt.”
Who pays?
These substances have been manufactured for consumer goods and exist because people buy them, which the panel argued makes the “polluter pays” principle difficult to enforce.
“These exist because we as consumers buy the products they are in,” Hill said in counterbalance to his own call for bans.
“We buy straws with PFAS, flame retardants on furniture, etc. – so when you think about polluter pays, who is the polluter? It’s all of us – so would you pay through general taxation for removal or through the water bill, higher prices on the product you buy? Who pays and in what amount?”
Bruce Jefferson, professor of water engineering, Cranfield Water Science Institute, called on government to “do the right thing” while the public narrative caught up with the issue. “We can’t wait for the public to agree with the message around this, we have to use the science now.”
With public perceptions of the water sector and trust in it already low, the panel doubted messaging that everybody has a responsibility for the chemical cocktails in rivers would be well received.
“We need to ask our politicians and industry to stand up and educate people more clearly for the public and media to understand,” Hill said. “I want to make people understand the problems that we have and understand it’s not ‘them and us’. We’re all responsible in what we buy and how we dispose of it.”
Warning against unintended consequences of banning substances, Jefferson said better education was essential to understand the trade-offs.
“We got rid of plastic straws because of microplastics, the replacements have a coating of PFAS on the inside to keep them secure.
“So next time you use a straw, you’re choosing to go down the PFAS pollution route rather than microplastics but we haven’t eliminated the problem, we’ve just switched it.”