Table of Contents
Request
Dear Environment Agency,
I am writing on behalf of North East Marine Research Group (NEMRG) to request the disclosure of environmental information under the Environmental Information Regulations (EIR) 2004. Our request concerns the Environment Agency’s role in assessing the impact of PD Teesport's maintenance dredging operations (specifically the extraction and overflow phases) on the Tees Transitional water body (GB510302509900).
The Tees Maintenance Dredge Protocol (MDP) Baseline Document (dated May 20, 2025) indicates that the Tees is currently failing for several priority substances, including PBDEs and mercury. We are concerned that the ongoing use of Trailing Suction Hopper Dredgers (TSHD) with active overflow by PD Teesport Limited is actively impeding the recovery of this water body by recirculating legacy contaminants that are concentrated on fine sediment particles.
We request disclosure of the following information from January 2023 to the present, or if there has been no communication in this period then from January 2014 to the present:
- Water Framework Directive (WFD) Compliance Assessments
- Request 1.1: Provide the EA’s formal review or response to the WFD assessment contained within the 2025 Tees MDP.
- Request 1.2: Disclose any assessments held by the EA regarding whether TSHD overflow constitutes a “new discharge pathway” that requires a specific assessment under your “Clearing the Waters” guidance.
- Request 1.3: The evidence used to prove that discharging of 25% to 30% of dredged material back into the river (via draghead disturbance and overflow) does not constitute a deterioration of the “Chemical Status” for PBDEs and mercury
- Impact on Protected Fisheries and Eels
- Request 2.1: Disclose all EA advice or data regarding the impact of dredging-induced turbidity and contaminant remobilization on the European eel (Anguilla anguilla), noting that eels have been detected in recent eDNA monitoring in the estuary.
- Request 2.2: Provide all internal reports discussing the risk of TSHD overflow plumes to migratory fish passage in the Tees.
- Contaminant Flux and Sediment Quality
- Request 3.1: Disclose all results from the EA’s “Intertidal Grab Sampling for Benthic Inverts and Contaminant” (Licence L/2013/00082) and any more recent WFD monitoring conducted in the Tees.
- Request 3.2: Provide the EA’s assessment of the “Sediment Trap” effect in the lower Tees and whether dredging overflow is causing a net accumulation of toxins in the surface “active layer” of the riverbed.
- Request 3.3: Assessment of whether the nitrogen and organic matter released during the agitation of anaerobic silts by the dredge head contributes to the “Unfavourable-Declining” status of the Seal Sands SSSI.
- Pollution Incident Investigation
- Request 4.1: Disclose all EA correspondence and data regarding the potential link between dredging operations and the crustacean mortality events of 2021-2022, specifically all analysis of water samples taken during active dredging campaigns.
- Request 4.2: Disclose all EA correspondence and data regarding the potential link between dredging operations and the ongoing harbour seal pup mortality events since 2021, specifically all analysis of water samples taken during active dredging campaigns.
For the avoidance of doubt, this request pertains specifically to the act of extraction and disturbance of sediment within the harbour limits. We are NOT requesting the Marine Licence or returns for sea disposal (e.g., MLA/2015/00088 and MLA/2025/00263). We are also not seeking information that is properly withheld pursuant to data protection requirements. Please provide the requested information within 20 working days.
Response
Environment Agency creating a better place for people and wildlife
Our ref: EIR2026/13001
Date: 14 May 2026
RE: Environmental Information Regulations: EIR2026/13001
We refer to your request for information regarding PD Teesport's maintenance dredging operations, which we received on 4 March 2026.
We are handling your request for information under the Environmental Information Regulations 2004 (EIR) as we have determined it to be a request for 'environmental information'.
We are aware that some of the information you have requested is readily available online or that we do not hold the information. Please see below our response to some parts of your request. Full details of supporting information and licensing are available when you access the data.
1. Water Framework Directive (WFD) Compliance Assessments
Request 1.1: Provide the EA’s formal review or response to the WFD assessment contained within the 2025 Tees MDP.
WFD assessments are completed by the developer/operator/consultant. The documents should be available on the MMOs online licence portal (Marine Case Management System in the public register), along with our responses: Marine case management system - Public register - MCMS
Request 1.2: Disclose any assessments held by the EA regarding whether TSHD overflow constitutes a “new discharge pathway” that requires a specific assessment under your “Clearing the Waters” guidance.
Information not held. The “Clearing the Waters for All” guidance does not explicitly identify Trailing Suction Hopper Dredger overflow as a “new discharge pathway” or state that it must be assessed as such. However, the applicant would still need to consider the environmental risks introduced by the overflow as part of the normal scoping and impact assessment process, even though the guidance does not label this as a special or distinct “new pathway” category. Regulation 12(4)(a) of the EIR states that a public authority may refuse to disclose environmental information to the extent that it does not hold that information when an applicant's request is received. Please see the appendix below for further details.
Request 1.3: The evidence used to prove that discharging of 25% to 30% of dredged material back into the river (via draghead disturbance and overflow) does not constitute a deterioration of the “Chemical Status” for PBDEs and mercury
Information not held. Regulation 12(4)(a) of the EIR states that a public authority may refuse to disclose environmental information to the extent that it does not hold that information when an applicant's request is received. Please see the appendix below for further details.
2. Impact on Protected Fisheries and Eels
Request 2.1: Disclose all EA advice or data regarding the impact of dredging-induced turbidity and contaminant remobilization on the European eel (Anguilla anguilla), noting that eels have been detected in recent eDNA monitoring in the estuary.
Information not held. Regulation 12(4)(a) of the EIR states that a public authority may refuse to disclose environmental information to the extent that it does not hold that information when an applicant's request is received. Please see the appendix below for further details.
Request 2.2: Provide all internal reports discussing the risk of TSHD overflow plumes to migratory fish passage in the Tees.
Information not held. Regulation 12(4)(a) of the EIR states that a public authority may refuse to disclose environmental information to the extent that it does not hold that information when an applicant's request is received. Please see the appendix below for further details.
3. Contaminant Flux and Sediment Quality
Request 3.1: Disclose all results from the EA’s “Intertidal Grab Sampling for Benthic Inverts and Contaminant” (Licence L/2013/00082) and any more recent WFD monitoring conducted in the Tees.
The information you have requested is available online as Open Data. EA Ecology & Fish Data Map Explorer | Water Quality , Water Quality Explorer, for the contaminant data. Any licence details will be available on the MMO licensing portal: Marine case management system - Public register - MCMS .
Request 3.2: Provide the EA’s assessment of the “Sediment Trap” effect in the lower Tees and whether dredging overflow is causing a net accumulation of toxins in the surface “active layer” of the riverbed.
Information not held. Regulation 12(4)(a) of the EIR states that a public authority may refuse to disclose environmental information to the extent that it does not hold that information when an applicant's request is received. Please see the appendix below for further details.
Request 3.3: Assessment of whether the nitrogen and organic matter released during the agitation of anaerobic silts by the dredge head contributes to the “Unfavourable-Declining” status of the Seal Sands SSSI.
Information not held. Assessment ‘Unfavourable-Declining“ status of the Seal Sands SSSI would sit with Natural England. Regulation 12(4)(a) of the EIR states that a public authority may refuse to disclose environmental information to the extent that it does not hold that information when an applicant's request is received. Please see the appendix below for further details.
We want to be as open as possible in answering requests, and to help you obtain the information you are looking for. However, our decision in this case is that the size of some of the request is too large. The cost and diversion of resources from our core work that it would take to deal with your request would be significant.
We estimate that it would take over 64 hours to comply with some of your request in its current form. This is based on staff time determining whether we hold the requested information, locating, retrieving and extracting information (from a document containing it).
In these situations, the EIR allow us to consider the application of Regulation 12(4)(b) to refuse a request on the basis that it is ‘manifestly unreasonable’ due to the time and resource it would take to respond to it. As it is estimated that it would take us approximately 64 hours to respond to your request in its current form, we consider that Regulation 12(4)(b) is engaged.
EIR Regulation 9 - Advice and Assistance
In line with EIR regulation 9(1) a Public Authority is required to provide advice and assistance to the customer in so far as would be reasonable to expect the Public Authority to do so. We are providing you with advice and assistance to help you reduce the scope of your request to focus on the precise information that you are seeking, for example by limiting the time-period or geographic area.
This is an opportunity for you to reconsider the size of your request and submit a new, refined request.
This is specific to the following part of your request:
4. Pollution Incident Investigation
Request 4.1: Disclose all EA correspondence and data regarding the potential link between dredging operations and the crustacean mortality events of 2021-2022, specifically all analysis of water samples taken during active dredging campaigns.
Request 4.2: Disclose all EA correspondence and data regarding the potential link between dredging operations and the ongoing harbour seal pup mortality events since 2021, specifically all analysis of water samples taken during active dredging campaigns.
We would also like to clarify that the Environment Agency does not specifically monitor water quality during dredge operations and that the Environment Agency has not been involved in seal pup mortality events. Investigations on mouth rot are led by DEFRA.
We would suggest you may find it helpful to browse through Environment Agency published data linked above. We have provided links to all our data available online regarding the crustacean mortality event and our water sampling data.
Please contact the North East Area Customers & Engagement Team at northeast-newcastle@environment-agency.gov.uk if you would like further advice on how to refine your request.
The application of Regulation 12(4)(b) is subject to a public interest test which requires us to balance the public interest factors in favour of disclosing the information against those in favour of maintaining the exception. We must also apply a presumption in favour of disclosure when carrying out this balancing test. The public interest test we have conducted is set out in the Appendix below.
Rights of appeal
If you are not satisfied with our decision, you can contact us within two calendar months to ask for the decision to be reviewed. We will then conduct an internal review of our response to your request and give you our decision in writing within 40 working days.
If you are not satisfied with the outcome of the internal review, you can then make an appeal to the Information Commissioner Office, the statutory regulator for the Environmental Information Regulations 2004 and the Freedom of Information Act 2000. Please follow this link to the ICO online complaints portal. The address is: Information Commissioner's Office, Wycliffe House, Water Lane, Wilmslow, Cheshire. SK9 5AF. Tel: 0303 123 1113 (local rate) or 01625 545 745 (national rate) | Fax: 01625 524510
Email:<icocasework@ico.org.uk >| Website: www.ico.org.uk
Yours sincerely
NE Area Customers and Engagement Team
To report environmental problems please visit www.gov.uk/report-environmental-problem or call the incident hotline on 0800 80 70 60
Appendix
Relevant exceptions
The exception that applies to the withheld information is:
Reg 12(4)(a) EIR - Information not held
Please see below where we have indicated that we do not hold any information.
Regulation 3(2) of the EIR states that information is held if it is in our possession and has been produced or received by us, or it is held by another person on our behalf at the time the request is received.
Information not held
In this case, some of the information you have requested is not held by the Environment Agency, and we are therefore refusing your request on the grounds that there is no information we can provide.
Where a request is for environmental information, the Regulations allow us to refuse to disclose it if the exception at Regulation 12(4)(a) of the EIR applies. The regulation states that a public authority may refuse to disclose environmental information to the extent that it does not hold that information when an applicant's request is received.
It is not possible for us to conduct a public interest balancing test because the reason for non-disclosure is that the information is not held.
12(4)(b) Request is Manifestly Unreasonable: ‘A public authority may refuse to disclose information to the extent that - (b) the request for information is manifestly unreasonable’.
The exception under EIR Regulation 12(4)(b) applies as the request is manifestly unreasonable due to the cost and/or burden dealing with your request would place on the Environment Agency.
The Public Interest Test
We have weighed the public interest factors in favour of maintaining the exception and find that they outweigh the public interest factors in disclosing the information. In carrying out the public interest test we have considered:
Factors in favour of disclosure: Openness, transparency and accountability - We understand that disclosure of information held by public authorities promotes transparency, accountability of public authorities, greater public awareness and understanding of environmental matters.
Factors in favour of maintaining the exception: Disproportionate burden - The amount of information that falls within scope of your request is considerable. Responding to the request would place an undue burden on the Environment Agency's resources and would require a substantial amount of resource and potentially the need to take staff offline from their cores duties to deal with the request. We consider that this burden cannot be justified due to the impact that responding to this onerous request would have on our ability to carry out our core duties. We consider this would be disproportionate to the benefit to the world at large in providing the information.
Having considered the public interest factors, and applying the presumption in favour of disclosure, we find that there is a stronger public interest in maintaining the exception than there is in disclosure.
Analysis
The overall conclusion must be that the EA does not hold information on the risks of the dredging operations as it does not hold data related to the operations or environmental assessment.
So the EA are not assessing the environmental impact of the maintenance dredging operations.
1. Water Framework Directive (WFD) Compliance Assessments
Request 1.1: Provide the EA’s formal review or response to the WFD assessment contained within the 2025 Tees MDP.
Refers me to Marine case management system - Public register - MCMS - which only contains information about the disposal not the actual dredging.
Request 1.2: Disclose any assessments held by the EA regarding whether TSHD overflow constitutes a “new discharge pathway” that requires a specific assessment under your “Clearing the Waters” guidance.
No information held which means that PD Ports has not supplied any and that EA has not requested any as it has not been informed that this is a discharge pathway.
Request 1.3: The evidence used to prove that discharging of 25% to 30% of dredged material back into the river (via draghead disturbance and overflow) does not constitute a deterioration of the “Chemical Status” for PBDEs and mercury
No infromation held.
2. Impact on Protected Fisheries and Eels
Request 2.1: Disclose all EA advice or data regarding the impact of dredging-induced turbidity and contaminant remobilization on the European eel (Anguilla anguilla), noting that eels have been detected in recent eDNA monitoring in the estuary.
No information held.
Request 2.2: Provide all internal reports discussing the risk of TSHD overflow plumes to migratory fish passage in the Tees.
No information held, I would suggest relates to 1.2. This is just not being considered.
3. Contaminant Flux and Sediment Quality
Request 3.1: Disclose all results from the EA’s “Intertidal Grab Sampling for Benthic Inverts and Contaminant” (Licence L/2013/00082) and any more recent WFD monitoring conducted in the Tees.
My assessment is that little useful data is available as the data sets are so sparse, I have looked at the online water quality data, but need to examine the ecology data more fully. The EA said available online as Open Data. EA Ecology & Fish Data Map Explorer | Water Quality , Water Quality Explorer
Request 3.2: Provide the EA’s assessment of the “Sediment Trap” effect in the lower Tees and whether dredging overflow is causing a net accumulation of toxins in the surface “active layer” of the riverbed.
No information held.
Request 3.3: Assessment of whether the nitrogen and organic matter released during the agitation of anaerobic silts by the dredge head contributes to the “Unfavourable-Declining” status of the Seal Sands SSSI.
No information stated to be Natural England's responsibility.
4. Pollution Incident Investigation
Request 4.1: Disclose all EA correspondence and data regarding the potential link between dredging operations and the crustacean mortality events of 2021-2022, specifically all analysis of water samples taken during active dredging campaigns.
EA does not monitor water quality during dredging operations. Defra lead for crustacean mortality event.
Request 4.2: Disclose all EA correspondence and data regarding the potential link between dredging operations and the ongoing harbour seal pup mortality events since 2021, specifically all analysis of water samples taken during active dredging campaigns.
EA does not monitor water quality during dredging operations. Defra lead for seal mouth rot investigations.