Troubled Waters:

The Forces Behind

The Death of

The Tees



Left and right: Fishermen and Environmentalists join forces to protest against dredging in the Tees. Centre: Tees Valley mayor, Ben Houchen, denies there is a link to ongoing projects at Teesworks

Scott Hunter

23 May 2022

The Tees Estuary is dying. Its demise the result of widespread contamination on the one hand, and a wilful mishandling of information on the other.

There was mass crustacean die-off in September/October 2021, and there has been a resurgence of this in recent weeks. We have also received numerous reports of deaths of seal pups as well as porpoise. Those seal pups that have survived are seriously underweight. Dead crab and lobster have been washing up on beaches again. Razor clams that inhabit the shallow waters of estuary beaches are also reported to be affected.

 Fishermen laying lobster pots report that when they retrieve them they find them filled with mud and silt. Divers at South Gare are reporting that the seaweed is dead.  They are also reporting that the seabed is covered in a layer of mud and silt.

Official Response Does Not Inspire Confidence



And the official response to these sobering facts currently appears to be a mixture of indifference, belligerence and denial. In recent comments to the Northern Echo, Tees Valley mayor, Ben Houchen, insisted that it had nothing to do with developments at Teesworks, and specifically the South Bank Quay, currently under construction. The Marine Management Organisation (MMO) which co-ordinated the original investigation into the deaths last year has closed the case. It is treating the latest emerging evidence as an unrelated to the 2021 die-off. 

Defra has recently set up the Cetacean Strandings Investigation Programme (CSIP) specifically to examine the seal and porpoise mortality in the area. Its effectiveness is in doubt, however.

When we spoke recently to marine mammal medic, Sally Bunce, she explained that she had been in contact with staff at this programme. She asked that they test the dead mammals for the presence of toxins including pyridine (pyridine was found in high concentrations in crab tissue during the first wave of crustacean deaths). She was informed, however, that Defra had allocated no budget for toxicology for any marine mammals.

Not for the first time, have Defra and its partner organisations been found wanting when there was a need for rigorous examination of the problem. Not for the first time have those affected by this ecological disaster wondered where Defra’s priorities really lie.

The Crisis: Past, Present, and Future

In this, the first of two reports, we consider how permissions given for the South Bank Quay on the Teesworks site may result in toxic material being dumped at sea, thus risking further die-off. We also consider how crucially relevant information about sediment toxicity is being kept out of the public domain. The second report will focus on factors that may have contributed to the earlier phases of this crisis.

Die-off and Dredging

Fishermen and others have repeatedly asserted that dredging in the channel has brought to the surface contaminants long buried in the sediment in the river and estuary beds. It is not unreasonable; after all, the Tees is the most polluted watercourse in the UK. Yet it is undeniable that their evidence is circumstantial, based on the coincidence of the die-off and some non-routine dredging commissioned by the harbour authority, PD Ports.

PD Ports, the harbour authority that has a statutory responsibility to maintain the channel to a specified depth, and therefore commissions maintenance dredging, has strenuously denied that this work is the cause of the problem, however. 

Tees Valley mayor, Ben Houchen, has repeatedly, and correctly, pointed out that capital dredging for the South Bank Quay project has not yet begun (the Licence period begins on 1 July 2022). His insistence that this means that the die-off has nothing to do with Teesworks is rather more problematic, however.

There is now both a crisis and an impasse.  No one wants to see the regeneration of Teesside founder. But preparing for the future necessarily involves dealing with the legacy of heavy industry and the relaxed attitude to environmental protection that accompanied it. 

Environmental Impact Assessment for Dredging in the Tees

The authority that licences dredging in the UK is the MMO. The licence obtained by the Tees Valley Combined Authority (TVCA) allows 1,800,000m³ of rock and sediment to be removed from the riverbed. As part of that application  (MLA/2020/00506 and MLA/2020/00507) it submitted an Environmental Impact Assessment (EIA). That assessment was conducted by Royal Haskoning DHV. Their report (RHSB) details, among other things, the condition of the river and estuary and of the regular maintenance dredging that takes place there. 

Dredging may be considered to present three environmental hazards. When sediment is raised from the riverbed and when it is dropped in the sea, it creates a plume. That plume results in oxygen depletion in the water, which is hazardous to marine life. A second hazard is the potential for the sediment at the drop zone to smother marine life on the seabed. The third is the disturbance of contaminants in the sediment that may then be released into the water.

Nonetheless, regular maintenance dredging takes place, and RHSB states that the practice has not changed since 2005. In previous years, it has not resulted in mass die-off. So, something has changed.

RHSB was published in November 2020. The reports now coming from divers and fishermen indicate that the composition of the estuary- and seabed has changed significantly in recent months. The urgent question is, therefore, where did this new material originate? And what levels of contamination might it contain?

Royal Haskoning Presents Evidence of Sediment Contamination

The Tees riverbed may be considered generally to consist of three layers – a sand/silt layer, below it soft clay, and below that the bedrock of mercia mudstone. The report goes into the matter of contamination in considerable detail. The rationale for this is that contaminants, once installed in the sediment, will remain there until that sediment is disturbed.

Regular maintenance dredging does not disturb those contaminated sediments. It operates mainly in the lower reaches of the river, between Tees Dock and Teesmouth, and removes, according RHSB, mainly clean sand that enters the estuary on the flood tide.

The risk of releasing contaminants comes when work is undertaken to deepen the channel, known as capital dredging. This is what is required to create the South Bank Quay. In order to allow large vessels to access the quay, the channel will be deepened from its current depth of 8.8m to 13m, except in the berth pocket, where dredging will be to a depth of 15.6m. The berth pocket is an area where the existing river bank will be cut away. This project involves removing a deep layer of contaminated sediment.

The South Bank Quay and the Northern Gateway Container Terminal

The South Bank Quay is not the only major engineering project on the Tees, however. Work on the long awaited Northern Gateway Container Terminal (NGCT) at Teesport is also due to start in the near future. This project is approximately 1km downstream of the quay.

 While Teesport wasn’t built until the early 1960s, what became the South Bank Wharf (shortly to be transformed into the South Bank Quay) was built towards the end of the nineteenth century, and remained in constant use throughout the twentieth. So, that wharf served the surrounding industry through the heyday of toxic dumping in the Tees and beyond.

Royal Haskoning also prepared the EIA for the Gateway project (MLA/2020/00079 henceforth, RHNG), which was presented to the MMO in early 2020. Unsurprisingly, given the sensitivities of the area, extensive testing of the riverbed was undertaken, and samples taken at no less than 37 sites between Tees Dock and Teesmouth.

It presents all of its raw data, then uses two scales to interpret them – one developed by the Centre for the Environment, Fisheries and Aquifiers (CEFAS, which is a branch of Defra), the other CSQG, which is the recognised international standard. The purpose of the scales is to indicate whether the levels of contamination are acceptable or critical. Where levels of contamination are above a certain level, the MMO will refuse permission of the sediment to be disposed of at sea and requires that it go to landfill.

The samples taken for the Northern Gateway show the presence of a large number of contaminants in the sediment, but particularly high concentrations of hydrocarbons. These results were much as Royal Haskoning had expected, given what was known about the history of the area.

Additional Data from the QEII Berth Project

Within the evidence presented in the licence application, reference was made to sediment sampling made in 2008 as part of what was known as the QEII Berth Project. The site of this project was immediately upstream of Tees Dock. The EIA for that project, now long since abandoned, was also prepared by Royal Haskoning. In the NGCT document it has this to say about the QEII project:

“Two vibrocores … sampled sediments to a depth of 4m below Ordnance Datum …

“As well as identifying contaminated sediments, the sediment quality survey also indicated a pattern of increasing contamination with depth. As a result of the contamination levels, the marine licence granted for QEII Berth stated that the fine unconsolidated material was not suitable for disposal to sea and only the Mercia mudstone constituent of the proposed dredge was licensed for offshore disposal. The marine licence states that the unconsolidated deposits need to be dredged using an enclosed grab, loading into a sealed barge to minimise re-suspension of sediment into the water column.”

Thus, immediately upstream of NGCT is evidence of sediment contamination so severe that the MMO refuses to allow it to be deposited at sea.

MMO Grants a Licence to NGCT

The Royal Haskoning Document NGCT was thorough and detailed, presenting evidence of sediment contamination levels both on the project site itself and an adjacent one. The application was then reviewed by the MMO and Cefas (the Centre for the Environment, Fisheries and Aquaculture, another branch of Defra). The licence was issued with no special conditions being placed on the disposal of dredged material. Dredged material from this scheme will be deposited at a drop zone known as Tees Bay C, about 12 km offshore.

South Bank Quay Application is a Document of a Different Quality

It would not be unreasonable to expect that the EIA for the South Bank Quay project would be prepared in the same way as that for NGCT, especially given that industrial exploitation in that area was much more prolonged and intense that around the NGCT site. This, in the event, was not the case.

Instead of sampling the sediment in the area of the South Bank Scheme and publishing tables of contaminant levels, this report presents once again the sample results from the NGCT project. Given the contamination risk of this area of the Tees, the failure to undertake any sampling whatsoever in the target area is quite astonishing.

Moreover, no mention is made of the QEII Berth Project, and the contamination levels found there. This is, if anything, even more astonishing, given that this site is closer to the South Bank site and actually overlaps it at one point.

In a nutshell, the Environmental Impact Assessment for the South Bank Quay was bodged. A remarkable lapse for a company like Royal Haskoning with an international reputation to maintain.

But we think it fair to presume that the company, given its wide experience of preparing EIA reports, knew what was coming next.

Cefas Reviews and Rejects the Environmental Impact Assessment

Cefas objects that no sample data on sediment quality from the site of the project were presented, and states that the application is unacceptable until this work is undertaken. That was an accident waiting to happen. So, what did Royal Haskoning think they were playing at? They must have known that they were going to have to go back and do it all again properly, jeopardising their reputation for thoroughness in the process.

Sample data were duly obtained at a later date and submitted to the MMO. The licence was granted, with certain conditions being placed on the disposal of sediment, of which more later.

So, what was the point of all that beating around the bush?

Who Stands to Gain from the Inadequate EIA ?

When a marine licence application is made, it is not the MMO that commissions the Environmental Impact Assessment, but the client. The client in this case is the Tees Valley Combined Authority (TVCA).   We have to ask, therefore, if the TVCA got what it asked for when it accepted and used the original bodged report. What did it stand to gain?

To answer this, it is well to recall some previous occasions when the TVCA, or the South Tees Development Corporation, have made controversial use of consultants and their reports. First was Primetals, commissioned to report on the feasibility of retaining the heart of the blast furnace as a monument. The published report claimed that this wasn’t economically viable, but it factored to its calculations the cost of building a visitors’ centre that was completely unnecessary.

Then there was the notorious incident of the demolition of the Dorman Long Tower, where Houchen and others claimed there was a structural engineers’ report that had concluded that the structure was unsound and could not be saved. That report was not put into the public domain until after the tower had been demolished, when it became clear that it had concluded nothing of the kind.

When it comes to the South Bank Quay project, a similar sleight of hand occurs. In the original application all of the sampling data is presented and published. The data produced subsequently to address Cefas’ objections, on the other hand, are not published.

And you only have to look at the amount of redaction in board papers from the TVCA and the South Tees Development Corporation to see that withholding material from publication is one of their trademarks.

At this point, in fact, we do not even know for certain who did the sampling (we assume if was the harbour authority). What we do know is that the data belong to the client, viz. the TVCA. Now the public has a right to see data on environmental issues, but anyone wishing to examine it would to apply to the TVCA, an organisation with a well-deserved reputation for secrecy. Obtaining the information could well involve months of wrangling.

But is there anything to indicate that we should be suspicious of the work that has been carried out?

MMO States That Some Material Can Not Be Dumped at Sea

Within the corpus of documents that make up the licence application is one, single page, document entitled ‘Conditions’. It states “The coordinates below must be excluded from the disposal at sea.” Below it are four sets of coordinates with no further comment.

Could this be the result of the latest sampling taken at the dredge site? We had a closer look at the coordinates. It turns out that they describe a very small area just to the north of the berth pocket, at a place marked on maps as ‘Tarmac Wharf’. What is interesting about this site is that it is at the point of intersection between the South Bank Quay site and the site of the QEII Berth project. That is to say, these are not new data. They are not the product of the latest sampling of the South Bank dredge site at all but originate in the data collected by Royal Haskoning for the QEII Berth in 2008. This means entire area sampled since the EIA was published has been deemed by the MMO to be suitable for dumping at sea. 

Put all together, the picture that emerges of the official view of contamination in the Tees is that from Teesmouth to Tees Dock (about 1.5km) shows elevated levels of hydrocarbon contamination but not so high as to preclude disposal of the sediment at sea. Immediately upstream of that is an area of about 0.5km in length, the site of the QEII Berth project where the contamination levels are so high that disposal of the sediment at sea is forbidden. Immediately upstream of that is an area of 1.3km in length where contamination levels are again low enough that disposal of sediment at sea is permissible. Is it any wonder that people are sceptical of the official line?

The Data Need to Be Published

Defra’s investigation into the die-off last year was lamentable. If Defra and the MMO are properly investigating the latest catastrophic events, there has been no statement issued about what they have found. The TVCA holds information that, if published, might reassure the public that the next stage of this ecological disaster is not about to happen.

Unless there is some commitment to transparency, suspicion lingers. And the suspicion is that political considerations have led to the suppression of evidence of a pollution incident in the Tees, and the imminent risk of further incidents.

Without that transparency, we cannot help but suspect that the poisoning of the Tees Estuary is considered by the powers that be as an acceptable level of collateral damage, collateral damage occurring in pursuit of the development of the free port, this government’s flagship policy.

Where Does That Leave the Inshore Fishermen and Other Stakeholders?

No one wants to see the regeneration of this region fail. Redevelopment and investment are vital. But for those who would object that nothing should stand in the way of creating new jobs in this area, we must point out that commercial fishing is also a job. Moreover, it is an indigenous industry, and, properly maintained, provides permanent employment.  Many of those fishermen are now going out of business, their catch so reduced that it is no longer economically viable to take their boats out. That their livelihoods should be sacrificed to some libertarian free trade fantasy is nothing less than intolerable.

Moreover, it is not only the fishing industry that is affected by this ecological disaster. The tourist industry of the North Yorkshire coast from Redcar to Bridlington is also at risk.

All that before we even get on to our collective responsibility to protect the marine environment off our coast.

Next Steps

Is the contaminated sediment around in the riverbed around the South Bank Quay the cause of the crustacean die-off that began last October? No, it is not.

The sediment will not release its toxic load until it is disturbed. Dredging will disturb it, but that will not occur before July at the earliest.

Does that mean that Teesworks has had no role in the die-off? No, such a conclusion is unwarranted. We consider this issue further in our next article.

Has there been a cover-up of the extent of contamination in that section of the riverbed? That appears to be the case. And it appears to be the TVCA that is responsible for it.

The riverbed has been sampled, but how extensively? That information is not in the public domain, but it needs to be.

Were samples taken at the same depth as those at the site of the QEII Berth? The QEII Berth sampling revealed that levels of contamination increased with increasing depth. We need to know that sampling at South Bank was done to the same standard. We suspect that it was not, yet permission to dredge there and to dispose of the sediment at sea has now been granted. That is unacceptable.

Until such time as the TVCA puts the relevant information into the public domain, the allegation rests, that the next stage of the South Bank project will yield yet more destruction of the marine environment. The allegation continues that the political aims of the free port scheme have been put above the duty to protect the marine environment and the economy dependent upon it.

We need answers. Sooner rather than later.

Royal Haskoning, the MMO and the Tees Valley Combined Authority have been contacted with requests for information/comment.  We await their response