LRM Global was requested by the client to conduct a site assessment at a service station near Bendigo, VIC. The purpose of the assessment was to ascertain the contamination status of the site prior to sale and determine whether it was suitable for ongoing use as a service station.
In order to determine the sites history, and therefore gain insight into the potential contamination status of the site, LRM conducted a preliminary site investigation. The preliminary site investigation involved a desktop review of historical titles, maps, aerial imagery, previous land uses and previous investigations. Based on this information, LRM determined that the most likely contamination exhibited onsite would be hydrocarbons and heavy metals originating from historical onsite practices. It was also determined that due to the underlying geology and shallow water-table, both the underlying soils and groundwater could potentially be impacted by contamination.
In order to determine the presence of contamination onsite, LRM Global conducted drilling works to obtain samples of the underlying soils and allow for the installation of groundwater monitoring wells. These works involved an underground service check of each location before coring works to remove a subsection of the concrete forecourt. The soil samples were then collected from a solid stem auger, with the underlying basalt drilled via air hammering. In instances where groundwater was intercepted, a monitoring well was installed and developed. Samples were collected from these monitoring wells after a twenty-four hour period, to allow for settling to occur within the well. All works were conducted in accordance with the WPCG Guidelines.
Sample results indicated that hydrocarbon contamination was present in the soil, likely resulting from leaking fill lines or spills from the onsite service-station. The exhibited contamination was identified to not exceed the Health Investigation Levels (HILs) or Health Screening Levels (HSLs) outlined within the National Environmental Protection (Assessment of Site Contamination) Measure (ASC NEPM) and so no further investigation into the onsite soils was required. Additionally, no contamination was identified in the onsite groundwater. Following the investigation it was determined that the site was suitable for ongoing use as a petrol station.
