Environment Presentation 7 January

Notes of the Presentation on the Environment by Paul Collins, Minsmere Levels Stakeholder Group & TEAGS; Public Meeting 7 January 2017

Borrow Pits and Spoil Heaps

  • EDF need to bury or send off-site about 1 million cubic metres of unsuitable material from the site excavation
  • EDF need good quality sand and gravel for the construction
  • EDF state they need about 15 hectares of borrow pit to achieve all of this, so the borrow pit will be at least 10 metres deep
  • Burying material in the borrow pit risks polluting the environment in both the short and long term
  • Material from the borrow pit and unsuitable excavation material will contribute to the spoil heap which will be between 20 and 35 metres high and clearly visible from Minsmere, Dunwich Heath, Leiston and Eastbridge
  • The spoil heap will be there for at least 6 years and be a potential dust pollution generator throughout its life

Water management

  • Rainwater run-off from the construction site will be quicker than occurs naturally and potentially could exceed the Minsmere sluice’s capacity causing water to backup and flood part of the Minsmere Levels
  • EDF will also have to deal with about a quarter of a million litres of effluent per day from the accommodation campus
  • Significant waste water and contaminated run-off will also be generated from the construction site areas such as the concrete batching plant – estimates of volumes have not been provided by EDF
  • Much of this water will need processing in the water treatment works that are to be built on-site before it can be released to the environment
  • The eventual proposal is that the treated water be pumped off site into the SZC “fish return” pipes that will exit into the bay some 400 metres from the shore.
  • This and the water treatment facilities are not going to be available for an appreciable length of time and in the meantime water will have to be allowed back into the marsh which is a significant pollution risk
  • EDF have no baseline studies to show the current flow rate from Sizewell Marshes into the Minsmere Levels to know when “to pump” and when “not to pump”

Causeways and Bridges

  • EDF’s preferred option is for a causeway and there are a number of reasons for this
    • It’s cheaper and quicker
    • The causeway and culvert could slow the natural process of seawater getting into the Sizewell Marshes
    • However, the causeway and peat below it would have no long term ability to resist the power of the tides and certainly not surge events like 2013 unless it is armoured in a similar way to that proposed for the SZC frontage
    • Compression of the peat by the causeway will affect the natural drainage from the Sizewell Marshes into Minsmere Levels
    • The bridge options will have the least effect on water flow between Sizewell Marsh and Minsmere Levels and allow coastal retreat to occur naturally
    • The bridge options could also allow access between Kenton Hills and the sea shore to be restored years earlier whereas the causeway would mean all access closed until all construction areas had been removed from the site

Jetty and Beach Landing Facility

  • In the Consultation Questionnaire, the BLF is shown as an option versus the two jetties
  • The BLF is not an option as elsewhere in the Stage 2 Consultation Document it is defined as a permanent facility
  • It will reach the shore sand dunes and piles will be permanently driven into the beach
  • The requirements for a jetty are heavily dependent upon the ability of the borrow pits to provide the raw materials EDF require for the build and to bury the million cubic metres of unsuitable material excavated from the site
  • There is no guarantee that the jetties can be built out to 800 metres and operated without damaging wildlife and accelerating coastal erosion
  • It is not known whether dredging will be required for the BLF and jetty which can disturb the natural coastal change processes
  • EDF have to remove the jetty once its use is over. There are no guarantees that this can be done successfully. Any remaining piles would present a clear danger to fishing boats and other craft
  • Overall, there is a risk of premature coastal erosion that threatens both Sizewell Marshes and Minsmere Levels.

Conclusions

  • The options presented in the consultation questionnaire treat the jetties, beach landing facility and borrow pits as independent options
  • However, according to their own documents they are interlinked and cannot be considered separately
  • We call on EDF to urgently publish its full Environmental Impact Assessment for the proposed development along with baseline, projected and cumulative effects on air, water, light, dust, noise and vibration pollution in a readable and understandable form as requested by the Secretary of State for Planning in May 2014

Theberton and Eastbridge Action Group on Sizewell

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