North East File Collection - NEFC

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.