North East File Collection - NEFC

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[[https://www.whatdotheyknow.com/request/request_for_information_under_th_110|3rd March 2026]]

===== Request =====

Dear PD Ports,

I am writing on behalf of North East Marine Research Group (NEMRG) to seek the following information relating to the Tees Maintenance Dredge Protocol (MDP) Baseline Document (dated May 20, 2025) and to PD Ports Ltd’s maintenance dredging operations.

==== 1. Trailing Suction Hopper Dredger (TSHD) Operational Data ====

The MDP acknowledges the use of the Emerald Duchess and Heortnesse but omits technical details on hopper overflow. Please provide the following:
   * Request 1.1: "Dredge Logs" for the last 24 months, specifying the exact duration of "overflowing" or "overspilling" for each dredge cycle, categorised by Reach.
   * Request 1.2: The technical specifications and operational settings for the "green valves" (turbidity control valves) on both vessels, including the threshold density and hopper loading level at which they are triggered.
   * Request 1.3: All internal reports and studies used by PD Teesport to validate the claim of environmental sustainability of the dredging operations, specifically that green valves contribute to environmental sustainability by reducing the mass flux of contaminants, as opposed to merely reducing visual surface turbidity.

==== 2. Estuarine Plume Modelling and Hydrodynamics ====
The MDP provides plume modelling for the offshore disposal site (Tees Bay A) but contains no equivalent modelling for the inner estuary reaches.
   * Request 2.1: Disclose all 3D hydrodynamic or sediment transport modelling held by PD Teesport that specifically simulates the "dynamic plume" and "passive plume" created by TSHD overflow.
   * Request 2.2: Provide all data regarding the "Sediment Trap Effect" in the Tees, specifically modelling how fine particles overflowed in the main channel are recirculated by flood-dominant currents into sensitive areas like Seal Sands.

==== 3. Contaminant Partitioning and "Fine Fraction" Enrichment ====
The MDP relies on bulk sediment sampling and Cefas Action Levels designed for offshore disposal rather than known toxicity of contaminants. It fails to account for the fact that hydrophobic contaminants (PAHs, PCBs, PBDEs) adsorb preferentially to the fine particles (<63µm) that are systematically released via overflow.
   * Request 3.1: Disclose all chemical analysis held by PD Teesport that was conducted specifically on the overflow water/fine sediment fraction, rather than bulk bed samples.
   * Request 3.2: Provide the raw data for the Year 9 (2024) mid-licence sampling, specifically the Total Organic Carbon (TOC) levels used to normalise PBDE concentrations, which the MMO noted as a point of concern.

==== 4. Water Framework Directive (WFD) and Protected Sites ====
The Tees Transitional water body is currently failing for PBDEs, mercury, and benzo(g,h,i)perylene.
   * Request 4.1: Provide the "WFD Compliance Assessment" specifically for the extraction phase, demonstrating that the remobilisation of these substances through dredging disturbance does not impede the recovery of the water body.
   * Request 4.2: Disclose any evidence used to conclude that dredging-induced turbidity does not impact the foraging success of Common Terns over their entire estuarine range, particularly in the silty upper reaches.
   * Request 4.3: Records of any Turbidity/Dissolved Oxygen monitoring conducted during the dredging process to ensure compliance with WFD.
   * Request 4.3: Formal Record of Decision or Test of Likely Significance regarding Teesmouth and Cleveland Coast SPA.

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 =====

1st May 2026 

==== Environmental Information Regulations (EIR) 2004: Request for information ====
We write further to your email to PD Teesport Limited (“**we**”, “**us**” or “**PD Teesport**”) dated 3 March 2025 in which you requested various items/categories of information, as follows (your “**Request**”). 
 
==== 1.  Trailing Suction Hopper Dredger (TSHD) Operational Data ====

   * 1.1  //"Dredge Logs" for the last 24 months, specifying the exact duration of "overflowing" or "overspilling" for each dredge cycle, categorised by Reach. //
   * 1.2 //The technical specifications and operational settings for the "green valves" (turbidity control valves) on both vessels, including the threshold density and hopper loading level at which they are triggered.// 
   * 1.3 //All internal reports and studies used by PD Teesport to validate the claim of environmental sustainability of the dredging operations, specifically that green valves contribute to environmental sustainability by reducing the mass flux of contaminants, as opposed to merely reducing visual surface turbidity. //

==== 2.  Estuarine Plume Modelling and Hydrodynamics ====

   * 2.1 //Disclose  all  3D  hydrodynamic  or  sediment  transport  modelling  held  by  PD  Teesport  that  specifically simulates the "dynamic plume" and "passive plume" created by TSHD overflow. //
   * 2.2 //Provide all data regarding the "Sediment Trap Effect" in the Tees, specifically modelling how fine particles overflowed in the main channel are recirculated by flood-dominant currents into sensitive areas like Seal Sands.//

==== 3.  Contaminant Partitioning and "Fine Fraction" Enrichment ====

   * 3.1 //Disclose  all  chemical  analysis  held  by  PD  Teesport  that  was  conducted  specifically  on  the  overflow water/fine sediment fraction, rather than bulk bed samples. //
   * 3.2 //Provide the raw data for the Year 9 (2024) mid-licence sampling, specifically the Total Organic Carbon (TOC) levels used to normalise PBDE concentrations, which the MMO noted as a point of concern. // 

==== 4.  Water Framework Directive (WFD) and Protected Sites ====

   * 4.1 //Provide the "WFD Compliance Assessment" specifically for the extraction phase, demonstrating that the remobilisation of these substances through dredging disturbance does not impede the recovery of the water body. //
   * 4.2 //Disclose  any  evidence  used  to  conclude  that  dredging-induced  turbidity  does  not  impact  the  foraging success of Common Terns over their entire estuarine range, particularly in the silty upper reaches. //
   * 4.3 //Records of any Turbidity/Dissolved Oxygen monitoring conducted during the dredging process to ensure compliance with WFD. //
   * 4.3 //Formal Record of Decision or Test of Likely Significance regarding Teesmouth and Cleveland Coast SPA. //

==== 5 Timing ====
 
In  our  letter  to  you  dated  30  March  2026,  we  explained  that  your  Request  is  varied  and  broad,  with  requested categories of records spanning lengthy time periods and that this would require searching through many years of records  for  requested  information.  On  the  basis  of  the  volume  and  complexity  involved  in  responding  to  your Request, we also confirmed that, as a result and as permitted by EIR, the deadline for responding to your Request was extended to 1 May 2026.  
 
==== Our Response ====
 
We can now provide our response to your Request and confirm that PD Teesport has undertaken required searches for any relevant records of information it may hold responsive to your Request, in line with its obligations under EIR.  
 
==== Duty to confirm or deny ====
 
We can confirm that PD Teesport holds some, but not all, of the information responsive to the Request. Some of the information is excepted from disclosure  under EIR, further information on this is set out  under the  “Exceptions” heading below. 
 
=== Request 1.1 - "Dredge Logs" for the last 24 months, specifying the exact duration of "overflowing" or "overspilling" for each dredge cycle, categorised by Reach. ===
 
PD Teesport does not hold information responsive to this part of your Request, as it does not have log sheets which specify the duration of “overflowing” or “overspilling”. To assist you, we have enclosed an example hard copy of a log sheet for the  Emerald Duchess. We  can also advise  you that PD Teesport  holds such log sheets for both the Emerald Duchess and the Heortnesse for the 24 month period requested, but has not provided these as part of this response as they do not specify the duration of “overflowing” or “overspilling” and so do not contain the information you have asked for. 
 
=== Request 1.2 - The technical specifications and operational settings for the "green valves" (turbidity control valves) on both vessels, including the threshold density and hopper loading level at which they are triggered. ===
 
PD Teesport holds information which responds to this part of your Request. However, it considers that it may be subject  to  the  exception  to  disclosure  under  Regulation  12(5)(e)  EIR.  More  information  is  provided  under  the “//Commercial information//” heading below. 
 
=== Request 1.3: All internal reports and studies used by PD Teesport to validate the claim of environmental sustainability of the dredging operations, specifically that green valves contribute to environmental sustainability by reducing the mass flux of contaminants, as opposed to merely reducing visual surface turbidity. ===

As above, PD Teesport holds information which responds to this part of your Request. However, it considers that it may be subject to the exception to disclosure under Regulation 12(5)(e) EIR. More information is provided under the “Commercial information” heading below. 
 
=== Request  2.1:  Disclose  all  3D  hydrodynamic  or  sediment  transport  modelling  held  by  PD  Teesport  that  specifically simulates the "dynamic plume" and "passive plume" created by TSHD overflow.  ===
 
PD Teesport does not hold information responsive to this part of your Request. 
 
=== Request  2.2:  Provide  all  data  regarding  the  "Sediment  Trap  Effect"  in  the  Tees,  specifically  modelling  how  fine particles overflowed in the main channel are recirculated by flood-dominant currents into sensitive areas like Seal Sands. ===
 
PD Teesport does not hold information responsive to this part of your Request. To assist you, we confirm that PD Teesport can provide data to show the chart areas that accumulate the most sediment and therefore are dredged the  most  if  this  would  be of  interest.  However,  we  do  not  hold  any  information  regarding the modelling  of  fine particles as requested. 
 
=== Request  3.1:  Disclose  all  chemical  analysis  held  by  PD  Teesport  that  was  conducted  specifically  on  the  overflow water/fine sediment fraction, rather than bulk bed samples. ===
 
PD Teesport does not hold information responsive to this part of your Request. 
 
==== Request 3.2: Provide the raw data for the Year 9 (2024) mid-licence sampling, specifically the Total Organic Carbon (TOC) levels used to normalise PBDE concentrations, which the MMO noted as a point of concern. ====
 
PD Teesport holds information responsive to this part of your Request and has enclosed relevant documents.  
 
=== Request 4.1: Provide the "WFD Compliance Assessment" specifically for the extraction phase, demonstrating that the remobilisation of these substances through dredging disturbance does not impede the recovery of the water body. ===
 
PD Teesport holds information responsive to this part of your Request. The Water Environment Regulations (WER) WFD Compliance Assessment was disclosed to your solicitors Goodenough Ring on 4 February 2026 in response to a previous EIR request and we’d direct you to that response. 
 
=== Request 4.2: Disclose any evidence used to conclude that dredging-induced turbidity does not impact the foraging success of Common Terns over their entire estuarine range, particularly in the silty upper reaches. ===
 
PD Teesport holds information responsive to this part of your Request.  The MDP has previously been disclosed to you.  To further assist you, we can advise  that relevant information is also available [[https://consult.defra.gov.uk/natural-england-marine/teesmouth-and-cleveland-coast-potential-sp/|here - Teesmouth and Cleveland Coast SPA, Ramsar Site and SSSI - Defra - Citizen Space. ]] 
 
=== Request 4.3: Records of any Turbidity/Dissolved Oxygen monitoring conducted during the dredging process to ensure compliance with WFD. ===

PD Teesport does not hold information responsive to this part of your Request. 
 
=== Request 4.3: Formal Record of Decision or Test of Likely Significance regarding Teesmouth and Cleveland Coast SPA. ===
 
PD Teesport holds information responsive to this part of your Request. The MDP has previously been disclosed to you.  The SPA was extended in 2020 to cover foraging terns (amongst other reasons), whilst maintenance dredging and disposal operations were ongoing. 
 
We  enclose  with  this  letter  copies of  the  requested information  held  by  us,  subject  to  applicable exceptions,  as explained below.  
 
==== Exceptions ====
 
=== Commercial information – Regulation 12(5)(e) ===

PD Teesport considers some of the documented information considered in relation to your Request falls within the exception  from  the  duty  to  disclose  information  under  Regulation  12(5)(e)  (the  “Commercially  Sensitive Information”) on the basis that it is commercial information and such confidentiality is provided by law to protect a legitimate economic interest, namely PD Teesport’s commercial interests, or those of a third party. This is because the information we hold which falls within limbs 1.2 and 1.3 is commercial information that has been provided by a third party and is labelled ‘Confidential & for information purposes only’. 
 
There are four which must be met for the exception to apply, namely: 

   - The information is commercial or industrial in nature. 
   - Confidentiality is provided by law. 
   - The confidentiality is protecting a legitimate economic interest. 
   - The confidentiality would be adversely affected by disclosure. 

//The information is commercial or industrial in nature.//

ICO  guidance  provides  explanations  of  what  will  be  considered  information  that  is  “commercial  or  industrial  in nature”, as well as specific examples of commercial and industrial information. The exception applies to information about  manufacturing  and related  industrial  processes.  The  information  responsive  to  limbs  1.2  and 1.3  provides details of regulatory information which we consider falls within the ICO’s examples of commercial information, as well as technical details about a product which we would consider to be industrial information. 
   
//Confidentiality is provided by law.//

We  consider  that  the  information  meets  the  test  under  the  common  law  of  confidence,  namely  that  it  has  the necessary  quality  of  confidence  and  that  it  was  shared  in  circumstances  creating  an  obligation  of  confidence. However,  to  assist  you  we  are  liaising  with  the  relevant  third  parties  and  have  asked  whether  they’d  have  any concerns  about  disclosing  the  relevant  information  to  you  and  therefore  assess  whether  an  actionable  claim  of confidence could be brought against PD Teesport. We are yet to hear back and will update you as soon as we can. 
  
//The confidentiality is protecting a legitimate economic interest.// 
 
ICO guidance provides a number of examples of “legitimate economic interests”, including “retaining or improving market  position;  ensuring  competitors  do  not  gain  access  to  commercial  valuable  information;  protecting  a commercial bargaining position in the context of existing or future negotiations; avoiding commercially significant reputation damage; and avoiding disclosures which would otherwise result in a loss of revenue or income”. 
 
We believe that our third party providers worked hard to ensure the continuing confidentiality of the information shared with us for the purpose of protecting their commercial interests including retaining its market position and protecting commercial valuable information from competitors and avoiding disclosures that would result in a loss of revenue.  This  is  evident  from  the  fact  that  when  sharing  the  information  with  us,  they  sought  to  be  as  clear  as possible that it would be necessary to protect such information from wider disclosure. However, as set out above, o assist you, we have consulted the relevant third parties to understand whether they have concerns about the confidentiality of the information shared with us. 
 
//The confidentiality would be adversely affected by disclosure. //
 
Disclosure of the information into the public domain will inevitably harm the confidential nature of the information within it, and that would also harm the legitimate economic interests that identified above.  
 
Whilst we consider the information to meet the test for the exception for the reasons set out above, as we have explained,  to  assist  you  we  are  liaising  with  the  relevant  third  parties  to  understand  whether  they’d  have  any concerns about disclosing the relevant information to you. We will update you once we have a response and will make further disclosures to you, if we are able to do so.  
 
=== Personal data – Regulation 13 EIR ===
 
You will note that redactions have been applied to the information that has been disclosed to you. This is because some of the information responsive to your Request was excepted from disclosure under Regulation 13 on the basis that  it  comprises  personal  data,  disclosure  of  which  would  “place  PD  Teesport  in  breach  of  at  least  one  of  the principles set out in the data protection laws, namely that “Personal data shall be processed lawfully, fairly and in a transparent manner in relation to the data subject” (Article 5(1)(e) UK GDPR)”.  
 
PD Teesport considered the potential lawful bases available to it for disclosure of the affected personal data to you. The  individuals  identified  in  this  information  have  not  consented  to  the  disclosure  of  their  personal  data  in  this manner, and so the only potential lawful basis under the data protection laws for making the disclosure would be that  the  processing  is  necessary  for  legitimate  interests  pursued  by  PD  Teesport  or  a  third  party,  in  making  the requested disclosure under EIR (including trying to assist you under EIR and being transparent about PD Teesport’s compliance with its obligations). However, the lawful basis would only apply to the extent that disclosure of the relevant  information  under  EIR  would  be  necessary  for  the  identified  legitimate  interests,  and  the  legitimate interests in disclosure would not be outweighed by the privacy rights and interests of affected individuals. 

Having considered the potential disclosure of affected details to the extent it relates to junior members of staff, external  individuals or  is  non-public  information  about  more  senior  staff,  we concluded  that  disclosure  of  those details is not necessary for the legitimate interests identified by PD Teesport.  
 
They  would  not  add  to  your  understanding  of  the  issues  mentioned  in  your  Request.  Employees  also  have  a reasonable  expectation  of  privacy  in  their  work  life  and  may  suffer  distress  or  upset  if  their  details  were  to  be disclosed publicly in response to the Request. As such, disclosure of this information is not necessary for legitimate interests  and,  in  any  case,  such  interests  would  be  outweighed  by  the  harm  or  distress  caused  to  the  relevant individuals due to disclosure of their personal data to you. Therefore, we do not consider that the lawful basis of legitimate  interests  is  available  to  us  and  disclosure  would  accordingly  breach  the  data  protection  principles, meaning that the exception under Regulation 13 applies. 
 
However,  you  will  see  that  public  function/official  related  personal  data  relating  to  senior  members  of  staff  or individuals in public roles at PD Teesport was disclosed wherever possible.  
 
==== Your right of complaint ====
 
If you have any concerns about this response, or any complaints about the handling of your Request to date, we offer an internal review (complaints) procedure.  
 
If you wish to use our internal review procedure, please contact Richard Ellison at dpo@pdports.co.uk. In the internal review procedure, your Request and our decision will be reviewed by a member of our organisation who had no input in the original decision. We will aim to conclude our internal review process within 20 working days of receiving your complaint. We will inform you if we consider that this timescale is unlikely to be complied with and will inform you of a likely response date. 
 
If you are still not satisfied following this, you can raise a concern with the Information Commission. The contact details are: 
 
Information Commission 
Wycliffe House 
Water Lane 
Wilmslow 
Cheshire 
SK9 5AF 
Tel: 0303 123 1113 
Website: http://ico.org.uk   
 
Kind regards 
 
Richard Ellison  

===== Analysis =====

No information has been supplied which suggests that any environmental impact assessment is carried out on the maintenance dredging operation.  In most case reference is made to documents where it is stated that the assessments are for disposal.

A trailing suction hopper dredger presents two sources of contamination:
   - the dredge head resuspending material which is not captured in the suction (up to 20% of dredged amount)
   - the overflow from the hopper (up to 25% of the dredged amount)

The response confirms that overflow happens every time the dredgers are deployed, but despite operating within the Tees SSSI, SPA and Ramsar, does not show any definition of the pathways when operating within the river.

There is no evidence of a least significant effect appraisal of the maintenance dredging operations.
==== 1. Trailing Suction Hopper Dredger (TSHD) Operational Data ====
   - Dredge logs - 1 supplied for 20th December 2025 - no information on overflowing.
   - Green valve - no information supplied as considered commercially sensitive.
   - Proof of environmental sustainability of dredging operations - no information supplied as considered commercially sensitive.

==== 2. Estuarine Plume Modelling and Hydrodynamics ====
   - Plume dynamics from overflow - no information held.
   - Sediment trap effect - no information held.

==== 3. Contaminant Partitioning and "Fine Fraction" Enrichment ====
   - Chemical analysis of overflow fraction - no information help.
   - TOC for mid-licence sampling - MMO templates supplied.

==== 4. Water Framework Directive (WFD) and Protected Sites ====
   - WFD compliance for extraction phase of dredging - pointed to previous WFD for disposal.
   - Dredging induced turbidity impact on terns etc. - MDP and should look at the [[https://consult.defra.gov.uk/natural-england-marine/teesmouth-and-cleveland-coast-potential-sp/|Teesmouth and Cleveland SPA, Ramsar Site and SSSI - Defra - Citizen Science]].  The MDP does not address operational dredging, the SPA link is a consultation, after the formation of the Tees Estuary Partnership designed to simplify continuing operations on the Tees via a Memorandum of Understanding which was signed in 2017 ([[https://marinedevelopments.blog.gov.uk/2017/11/16/tees-estuary-regulation-partnership-licence/|Improving regulation in the Tees Estuary]]) making the MMO the primary regulator for the Tees.  All these links basically assume that current business as usual is having no environmental effect.  Rather than saying is business as usual safe to continue, and certainly should be revisited after the 2021 crustacean die-offs and the ongoing harbour seal pup mortality.
   - Records of turbidity / dissolved oxygen - PD Teesport holds no records.
   - Test of likely significance SPA - MDP and extension of SPA.  Without plume modelling once again these documents refer to the disposal not the dredging operation.