Burrill-Lake-Preliminary-Environmental
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Appendix E Contamination assessment 21/21478/181987 Burrill Lake Bridge Environmental Investigations Roads and Maritime Services Report for Burrill Lake Bridge, Princes Highway Contamination and Hydrogeology Investigations September 2012 Contents Executive Summary i 1. Introduction 1 1.1 Introduction 1 1.2 Objectives 1 1.3 Scope of Works 1 1.4 Existing Information/Reports 2 2. Site Information 3 2.1 Site Identification 3 2.2 Surrounding Land Uses 3 2.3 Site Inspection 3 2.4 Site History 4 3. Environmental Setting 8 3.1 Topography 9 3.2 Soils and Landscapes 9 3.3 Acid Sulphate Soils 9 3.4 Geology 9 3.5 Hydrogeology 11 3.6 Groundwater Elevations 12 3.7 Hydrology 12 4. Regulatory Information 13 4.1 Overview 13 4.2 Office of Environment and Heritage (OEH) Searches 13 5. Preliminary Conceptual Site Model 14 5.1 Potential Sources of Contamination 14 5.2 Potential Contamination Migration Pathways 14 5.3 Potential Receptors 14 5.4 Potential Source-Pathway-Receptor Linkage 15 6. Potential Constraints 16 6.1 Contamination Constraints 16 6.2 Hydrogeological Constraints 17 21/21478/180126 Burrill Lake Bridge, Princes Highway Contamination and Hydrogeology Desk Study 7. Conclusions 18 8. References 20 9. Limitations 21 Table Index Table 1 Site Inspection Summary 3 Table 2 Review of Historical Aerial Photographs (On-Site) 4 Table 3a Summary of Proprietors - 119 Princes Highway, Burrill Lake 5 Table 3b Summary of Proprietors -5 Princess Avenue South, Burrill Lake 6 Table 4 Published Geology 9 Table 5 Subsurface Conditions based on Nearby Borehole Information 10 Appendices A Figures B Site Photographs C Aerial Photographs D Regulatory Information 21/21478/180126 Burrill Lake Bridge, Princes Highway Contamination and Hydrogeology Desk Study Executive Summary GHD Pty Ltd (GHD) was commissioned by the Road and Maritime Services (RMS) to undertake a Phase I Environmental Assessment of Burrill Lake Bridge and causeway as well as the surrounding land, Princes Highway, Burrill Lake, NSW (the study area). RMS is currently investigating options for the replacement or maintenance of the bridge. The objectives of the assessment was to document the study area historical and current site operations to enable identification of potential contamination sources, provide a desk-based review of site information including hydrogeology, hydrology, topography, geology and soils, and provide an assessment of the potential liabilities associated with site contamination. Based on historical information collated during this assessment, the study area has had relatively minor development from 1950. Further development of the commercial and residential properties of the surrounding area of the bridge/causeway has occurred since 1950. The Princes Highway and local streets linking to it have been there since at least 1950. The original bridge was built in 1818 and was replaced in 1958 with the current bridge. The Burrill Lake Bridge provides the only road crossing of Burrill Lake in the local area. The study area is surrounded by mixed land uses, however most are residential or commercial properties. The study area is of moderate environmental sensitivity. Based on the continued use of the study area at the current land uses, the study area generally represents a low contamination risk. However, potential constraints to the redevelopment in the area do exist. In addition, a former service station with associated soil and groundwater impacts was also identified immediately east of the site boundary, on the northern side of Burrill Lake. The above ground infrastructure has been removed, however the current status of the underground infrastructure and impacted soil and groundwater is not known. Potential constraints and their management options include: Asbestos material: Removal of asbestos pipes on the bridge by class B (bonded) asbestos license contractor, to prevent any risk of contamination migration; Contaminated fill: If fill within the causeway is likely to be disturbed, characterise the materials for contamination and produce management plans during construction works; Acid sulphate soils: If soil/sediments within the area are likely to be disturbed, tests should be done to assess if acid sulphate soils are present to verify if management measures are required during construction; Bridge construction: Understand the piling/footing options to establish and undertake a piling/groundwater effects assessment; and Groundwater assessment: If the works are to intersect groundwater, dewatering of the aquifer system may be required during construction activities additional investigations should be completed to assess the quality of groundwater and the potential impacts on surrounding groundwater users and on the Quaternary aquifer resource. Former Service Station: Assessment of soil and groundwater impacts, presence / absence of underground infrastructure, and potential remedial works prior to undertaking construction activities in the vicinity of the former service station property. 21/21478/180126 Burrill Lake Bridge, Princes Highway Page | i Contamination and Hydrogeology Desk Study 1. Introduction 1.1 Introduction GHD Pty Ltd (GHD) was commissioned by Roads and Maritime Services (RMS) to undertake a Phase I Environmental Assessment of an area surrounding Burrill Lake Bridge, Princes Highway (the study area). The study area is located about six kilometres south of Ulladulla. The study area locality plan is provided in Figure 1 (Appendix A). It is expected that the bridge will require either replacement or substantial maintenance in the next 10 years to retain its functionality. RMS is currently investigating options for the replacement or maintenance of the bridge. 1.2 Objectives The objectives of the Phase I Environmental Assessment were to: Summarise the study area history and operations to enable identification of potential contamination sources; Summarise the study area’s environmental setting including; hydrogeology, hydrology, topography, geology and soils; Summarise the potential for contamination in the context of the study area’s current land use; and Provide RMS with the potential constraints to the upgrade/redevelopment of Burrill Lake Bridge, Causeway and the Princes Highway in the study area to assist with the development of future upgrade options. 1.3 Scope of Works To meet the stated objectives, GHD completed the following scope of work: Site history review including: information held by the NSW Office of Environment & Heritage (OEH) searches: the contaminated land record and Environment Protection licences, applications or notices record; review of historical aerial photographs and historical title deeds; and review of relevant information held by Council and any previous environmental / geotechnical / hydrogeological investigation reports that are available. A desktop review of the soils, geology and hydrogeology of the site including review of published information such as soil, geology and acid sulphate maps, and a search of the NSW Natural Resources Atlas (groundwater database); review of published aquifer characteristics data such as expected hydraulic conductivities; and review of published salinity and acidity data for the site and surrounding area; A detailed inspection to identify areas of potential contamination based on observation of surface conditions, and evidence of current or former potentially contaminating facilities; Preparation of a conceptual site contamination model of the study area to identify the key potential sources, pathways and receptors of potential contamination; and Preparation of a technical report clearly documenting the potential for contamination at the study area and providing potential constraints to the development constraints. 21/21478/180126 Burrill Lake Bridge, Princes Highway Page | 1 Contamination and Hydrogeology Desk Study 1.4 Existing Information/Reports GHD has been provided with the following information regarding the study area: Roads and Traffic Authority (RTA), Environmental Planning and Assessment. Preliminary Environmental Investigations: Burrill Lake Bridge, December 2010; Aurecon, Strategic Concept and Options Study Burrill Lake Bridge, December 2010; RMS, Burrill Lake Bridge – Environmental Investigations Brief; March 2012 BMT WBM Pty Ltd, Burrill Lake Catchment Flood Study, July 2007; Shoalhaven City Council, Burrill Lake Estuary and Catchment Management Plan, December 2002; and HLA Envirosciences, Detailed Site Investigation Lots 212 to 215 DP 15648 Burrill Lake, NSW (Draft Report), May 2002. 21/21478/180126 Burrill Lake Bridge, Princes Highway Page | 2 Contamination and Hydrogeology Desk Study 2. Site Information 2.1 Site Identification The study area consists of Burrill Lake Bridge and causeway, local streets, a section the Princes Highway on the eastern and western side of the bridge and a portion of Burrill Lake in the vicinity of the bridge. There are various commercial and residential properties within the study area including holiday apartments and tourist (caravan) parks as well as recreational parklands. The study area location is shown on Figure 1 (Appendix A). 2.2 Surrounding Land Uses The following land uses surround the study area: North: Burrill Lake (upstream) and Stoney Creek; East: residential and commercial properties, littoral forest followed by beach; South: Burrill Lake (downstream) and ocean entrance, parkland, beach, residential properties and a tourist (caravan) park; and West: residential and commercial properties and parkland. 2.3 Site Inspection