Newlands Cross Upgrade EIS - European Investment Bank

South Dublin County Council N7 Newlands Cross Upgrade
Environmental Impact Statement
Arup Consulting Engineers
Management Act, 1996, and associated regulations including the EU Landfill Directive and its
Annexes, as well as the requirements of the receiving facility.
The use of rock breakers should be adopted to break up any rock in service trenches to
minimise the volume of rock excavated.
The potential pollution of soils and groundwater during the construction phase will be
mitigated by the provision of appropriate controls and working methods and are outlined in
Chapter 14. These methods include bunding around diesel/petrol storage tanks and vehicle
maintenance areas and will be addressed in the Contract documents.
6.5.2 Operational Phase
Once operational, the geology on site will be protected from the elements. Subsoil will either
have a surface road dressing or topsoil covering it and topsoil will be grassed to prevent
erosion, no rock will be exposed.
Planting of slopes and correct drainage will protect against erosion of material or leaching of
nutrients.
No road drainage outfalls from the proposed road development discharge to existing
watercourses. All drainage discharges are proposed to outfall to existing surface water sewers.
Petrol interceptors and emergency spill containment facilities will be incorporated at outfalls
as appropriate. These facilities will be installed as a risk management measure to help prevent
any adverse impacts from potential spillage from road accidents. This topic is dealt with in
detail in Chapter 14.
6.6 Residual Impacts
Residual impacts include the excavation and compaction of soil. Shallow excavation of
materials is required through out the area of the junction improvements for road regarding and
embankment construction.
The sub-soil beneath embankments will be compacted to achieve the relevant engineering
design values prior to embankment construction. This compaction is a permanent impact.
Residual impacts on the hydrogeology include the potential for groundwater contamination
during the operational phase. Although as the construction works will generally result in a
greater depth of covering over the bedrock aquifer than is currently there, it could be
considered that the works will reduce the vulnerability of the bedrock aquifer.
The proposed development will result in an impermeable surface being constructed over the
bedrock aquifer. This may have the effect of a minor reduction of groundwater recharge to the
aquifer.
December 2007 Page 102