Severn Seabed mapping of humped material - NRW in denial

The Cardiff Grounds dump-site (LU110) normally disperses dumped dredgings in the strong currents, but the Titan survey identified a lot of mounds on the seabed around a metre high and 30 metres across. Their radar survey was carried out 6 months post-dumping from the huge Pagadder and Shloeber barges of Hinkley material. As the site is supposed to be a dispersal site where material is swept away in the strong currents, NRW asserts the site is “sustainable” as the material would “disperse over time”. They also claim the sea bed has not been raised on the average, though Titan’s mapping shows it’s generally higher.
A third claim by NRW is that it’s impossible to attribute the left-over sediment to Hinkley.

Penarth Times report 10 September 2020

Here is one of Titan's detailed images - seabed height differences between the April 2019 and 2018 surveys

The images show a series of four discrete disposal events along a transect (“Transect 01”), with each disposal identified as two parallel lines of deposited material (i.e., accretion), consistent with material being released through the hopper doors of a dredging vessel.

To the left is Titan’s result that implies accretion (orange) through much of the area as well as the mounds showing recent dumping. to the right is NRW’s favoured adjustment that implies the area has generally eroded (white to blue), except for the humps. This 'adjustment' comes from moving up the zero by 24cm. This picture shows that though an adjustment be a few cm is possible, 24cm is implausible. The mounds would be expected to spread and raise the adjacent levels.

Elevations were also depicted by Titan's Figure 7:


It appears that these parallel mounds did not spread much laterally in the 6 months post dumping, except for the right-most trail where the left side slumped into the depression.

Grab-samples of the seabed were also collected by Titan. One sample taken happened to be quite close to the lowest of the 4 trails (upper picture); it has an extreme composition of 95% mud and is characterised as “very poorly sorted”. The sample point (S4) happens to be along the parallel trail and within about 30m of the metre-high mounded material. It’s highly likely to come from Hinkley, not from a shipping channel dredger.

The Titan report is in no doubt that they see deposition in the April 2019 survey compared with the pre-dumping survey in 2018. They looked carefully into the zero-ing uncertainty, settling on 8.5cm. The NRW's 24cm on top of this implies erosion of the seabed in the area of the mounds. They are in denial not just that the mounds are Hinkley material, but also that much of the dumped material could have remained in the dump site.

NRW refuses to disclose the Cardiff dump-site Licence

NRW refuses** to disclose the Licence they hold for the Cardiff Grounds dump-site.

NRW are the WG’s marine licensing authority, yet say FoE have to go to the Welsh Government for the licence (dating from the 1980s).  

FoE believes the licence applies for sediments from dredging ports and shipping channels and does not permit dredgings from the capital works at Hinkley Point.  NRW refuse to disclose the licence because it would show they ignored it for the previous dredging campaign.

NRW fail to require EDF to show why they seek to dump a further 600,000m³ (840,000 tonnes).  This volume is more than twice the original demand, on top of the original plan. There is no planning permission for this extended 'dredging'.

Nor do NRW report on compliance with the dumping license issued to EDF.  A condition was placed on the previous dumping that material be spread throughout the dump-site, to avoid mounding of the clays and gravels.   We think they failed to spread it evenly and dumped material outside the limits of the dump-site. 

MV Sloeber opening its bottom to dump Hinkley mud on 16 October 2018.
It was caught with its bottom opened (sh***ing) outside the dump site.

The NRW allowed EDF to submit a Summary of Dredging Campaign 2018-19 that fails to meet quality requirements for reporting and specifically the international OSPAR requirements.

NRW told everyone that they met all the international licensing requirements on sea-dumping last time.  They did not.  They ignored the 2014 IMO guidelines that require them to minimise sea dumping, and expect to do the same again. 

The 1972 London agreement stopped sea dumping, with some exceptions for dredging operations.  The Protocol added in 2014 tightened  the requirement to reuse dredged material on land.  NRW are still in the dark ages, believing that sea dumping is the first choice.

## Hinkley Mud: NRW flouts licence rules gives FoE's detailed response to NRW's proposal ##

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** NRW Refusal

On Tue, 11 Feb 2020 at 12:27, Marine Licensing <marinelicensing@cyfoethnaturiolcymru.gov.uk> wrote to Friends of the Earth Barry&Vale

Thank you for your email to Mr Evans. As part of a pre-application request the Marine Licensing team has received the proposed sample plan from EDF for further dredging at Hinkley Point C construction site. This will help us understand whether the material can be deemed suitable for disposal at sea. We have not received a marine licence application from EDF. The consultation we are running is to provide members of the public with the opportunity to express their views on the suitability of the submitted sample plan and this will inform our pre-application response. 

As with regards to your question of the operating licence for Cardiff Grounds; this disposal site is ‘designated’ by Welsh Government and further information on its designation should be requested from them. The area has been used since the mid-1980s and each marine licence application for disposal at the site is assessed on its own merits. 

Regards,  Maria

   Trwyddedu Morol/ Marine Licensing

   Cyfoeth Naturiol Cymru / Natural Resources Wales