AGS provides a variety of services to allow a comprehensive assessment and management of our clients' above and below ground risks. Broadly speaking, the services can be divided into three main areas; Asbestos, Groundwater and Soil.
Our asbestos services typically relate to fixed asbestos and hazardous materials audits of buildings, however asbestos debris in soils is treated as a soil contamination issue. Soil and groundwater services are often combined into Environmental Site Assessments (ESAs) or Detailed Site Investigations (DSIs).
Environmental Site Assessments / Detailed Site Investigations
Assessing impacts to human health and the environment from land use causing contamination or the importation of contaminated soils is important to prevent unacceptable risks. Segments of the environment that can be impacted by contamination and require assessment include soil, groundwater, air and soil gas (gas within soil pore spaces produced by contaminants in soil or groundwater that may pose a vapour intrusion risk to building occupants). Asbestos contamination (both fixed to buildings / structures and debris or fibres within soil) presents another source of potential risk that requires management or remediation.
Assessment and remediation of these types of contamination is enshrined in both national and state legislation and guidance is provided through multiple governing bodies. Where unacceptable risks are shown to be present, either clean-up of the contamination or mitigation of the risks through engineered controls (with ongoing management) is required. Both of these scenarios can result in significant hidden costs.
Environmental Site Assessments (ESA) or Detailed Site Investigations (DSI) can be undertaken for many reasons; during a due diligence phase prior to purchase, to determine the baseline contamination status of a site for leasing arrangements, as a result of legislative requirements during the planning / development process or in response to impacts to human health and the environment. Due diligence and baseline assessments are becoming increasingly common as investors, developers, lessees and lessors and government bodies become aware of the large financial risks involved in contaminated site clean-up and management. Legislative requirements for an ESA/DSI, or a statutory Environmental Audit, are often required by council as part of planning permit conditions where a change in land use is proposed, or the site has an environmental audit overlay.
Types of Environmental Site Assessments
Environmental Site Assessments (ESA), can take many forms and are tailored to suit client, budget and legislative requirements. ESAs typically progress in a staged fashion, whereby results of preliminary assessment stages inform the scope and design of subsequent stages. This iterative nature is preferred as it minimises costs whilst ensuring all potential contamination risks are appropriately characterised. The staged process can, however, result in prolonged project completion times, and due to the high holding costs of financed property, clients often express concerns at projected timeframes.
Typically an assessment will begin with a Phase I Site History, or Preliminary Site Investigation. Following the completion of this, an intrusive assessment of soil and groundwater may be undertaken to sample and analyse soil and groundwater beneath a site.
Due diligence and baseline assessment are usually designed to provide adequate information in order to determine the contamination status of a site with a single site mobilisation, sampling and reporting event. These can be tailored to a clients’ objectives and budget, bearing in mind that the less sampling and analysis undertaken, the greater the uncertainty of the contamination status of the land.
Assessments that are in response to legislative requirements often require multiple separate mobilisation and site sampling events to sufficiently assess and delineate any contamination issues at the site. As part of ensuring that the site is suitable for the proposed land use, the assessment may include removal of above and below ground infrastructure and subsequent validation sampling to ensure any impacted soils around the infrastructure has been removed, remediated, or is shown to pose an acceptable risk to the proposed land use and can be re-used on-site. If soils and groundwater are shown to be impacted by contamination, remediation of soils and groundwater may be required. A cost benefit analysis may also be undertaken to determine the risk of leaving contamination on site and if ongoing management of contamination is preferable to removal or remediation.
Phase I Environmental Site Assessments / Preliminary Site Investigation
A Phase I Environmental Site Assessment or Preliminary Site Investigation provides information relating to the current and previous site owners/occupiers in order to determine activities which may have resulted in site contamination, the likely type of contaminants to be found onsite, and possible locations to be targeted during site investigation works.
An assessment of the existing conditions of the site is also performed, which focuses on current site activities, the presence of fuel storage tanks, chemical stores, surface staining, poor or sparsely vegetated areas, odours and an assessment of site drainage and topography. A review of the surrounding area, including industry, land use and groundwater conditions is also undertaken to determine any potential off-site sources of contamination.
Following collation of all relevant information, an indication of the potential for site contamination can be provided, and the extent of any preliminary soil/groundwater sampling required can be determined.