This content requires Adobe Flash Player version
or later.
Either you do not have Adobe Flash Player installed,
or your version is too old,
or there is a problem with your Flash installation and we were unable to detect it.
Contamination of groundwater by construction operations
Disturbing existing drainage systems/impacts to private water supplies.
Conclusion
Overall use of pre-installed ducts would produce a lower impact through a reduction in the area to be excavated. Most clear is the removal of the need to trench the extent of the cable route, with excavations required for jointing pits only.
Table 1.3. Potential Impacts on Air Quality Option 1: Pre-Installed Ducts
Dust impact for ecology/Dust Soiling / PM10
Vehicle emissions
Less dust on site and less transport of spoil off site
Construction traffic flows along the proposed access routes were of an order considered to generate not significant air quality impacts.
Conclusion Option 2: Open Trenching
Greater excavation, more dust on site and greater transport of spoil off site
Construction traffic flows along the proposed access routes were of an order considered to generate not significant air quality impacts.
Overall use of pre-installed ducts would produce a lower impact than undertaking direct cable laying for each of East Anglia THREE and East Anglia FOUR. This conclusion is reached through the removal of the need to undertake excavations and direct cable lay across the length of the onshore cable route. Option 1: pre installed ducts requires excavations of jointing pits only.
Table 1.4. Potential Impacts on Water Resources and Flood Risk Option 1: Pre-Installed Ducts
Properties in Flood Zones Flood defences Groundwater
Surface water quality to suspended solid content
Surface water quality to Pollution Abstractions
Not significant No works required
This would be covered by EMP therefore no impact/impact mitigated and within compliance limits
Option 2: Open Trenching Not significant HDD required below defences
This would be covered by EMP therefore no
impact/impact mitigated and within compliance limits