Warrawee Substation - Review of Environmental Factors

Assessment of the environmental impacts and risksSoilsThe proposal would require the excavation of spoil to provide the required space forthe new substation. Spoil would be reused on site where possible. Where reuse is notfeasible, spoil would be removed from the site and disposed of to a licenced facility.Obvious signs of potential surface contamination such as dumping and discolourationof the ground surface was not identified during the site inspection for the REF. It isunderstood that the adjacent rail corridor does not include services or infrastructurethat would lead to an increased risk of contamination, such as oil-filled cables orchemical storage tanks. Based on this, it is considered that there is a low likelihood ofsignificant contamination being present on the site. Asbestos was historically used inbrake linings and it is possible that asbestos fragments may be present in the soil. Inthe event that suspected contamination is identified during construction, mitigationmeasures in Section 3.1.3 would be implemented and this would include testing toconfirm the nature of the contamination and the management and disposalrequirements in accordance with DECC's Waste Classification Guideline 2009.Erosion and sedimentationThe following construction activities have the potential to expose soils which couldpotentially cause erosion and sedimentation of surrounding land, urban areas anddrainage lines:Vegetation removalExcavation of the substation site and access roadsExcavation of trenches to relocate servicesVehicle movementsStockpilingLandscapingRehabilitation of temporary stockpiles and construction compoundThe above activities would expose soil, which has the potential to cause erosion andsedimentation and may result in issues such as degradation of water quality (seesection 3.3.2) and sedimentation of nearby waterways such as the water coursecarried under the rail corridor via a culvert, to the south of the southern extent of theworks. The impacts of erosion and sedimentation would be minimised byimplementing control measures outlined in Section 3.1.3.OperationThe proposal would not result in any impacts to topography, geology and soils duringoperation.3.1.3 Recommended control measuresThe following control measures would be implemented to minimise adverse impacts:An erosion and sedimentation control plan would be developed and incorporatedinto the Construction Environment Management Plan (CEMP). The plan wouldWarrawee Substation Project/Review of Environmental FactorsPage 19 of 64