Hurstville REF - Transport for NSW - NSW Government

4 Environmental Impact and Risks4.1 Landforms, Geology and SoilsExisting SituationThe proposed site is inside the railway corridor approximately 10 metres north of the railwayline. The proposed DBS site is in a cleared gravel area. The geology comprises WianamattaGroup of black to dark-grey shale and laminite, underlain with Liverpool subgroup of shale withsome sandstone beds. The soil is of the Glenorie soil landscape type, which is comprised ofshallow to moderately deep Red Podzolic Soils, Red and Brown Podzolic Soils, and YellowPodzolic Soils, and has high erosion potential once exposed.NSW Acid Sulfate Soils (ASS) risk mapping provided by the NSW Office of Environment andHeritage (OEH) indicates the proposed site is in an area of no known occurrence and noexpected occurrence of ASS.A geotechnical review has not yet been undertaken for Outdoor Location 2. This review will becompleted prior to construction to anticipate the presence of contaminated material on site andto confirm the site is suitable for the proposed use. Prior to construction UGL will confirm groundconditions by:On-site inspections during pre-construction site reviews to confirm desk-top studypredictions.Potential ImpactsApproximately 60 square metres and 20 square metres will be disturbed at Outdoor Location 2and Outdoor Location 3 respectively during construction of the proposed DBS site. Excavatedsoil and rock will be stockpiled and removed from the site if it cannot be used elsewhere on thesite. The foundation for the monopole will result in about five cubic metres of spoil (not includingtrenching). The trenches for the cables will be backfilled upon completion.Excavation and trenching activities may result in erosion if appropriate mitigation measures arenot in place. Soil erosion has the potential to destabilise landforms and deposit sediments indrainage systems and waterways. Sediment deposition and fine particles in suspension withinwaterways have direct impact on water quality and aquatic life.Given the site characteristics and the scope and size of the proposed work, it is anticipated thaterosion and sediment risks are minimal and can be effectively managed through theimplementation of standard measures as outlined in the Landcom/Department of HousingManaging Urban Stormwater, Soils and Construction Guidelines (the Blue Book) (Landcom2004).No operational impacts are expected.Page 32 of 75