Environmental site assessment and asbestos abatement during site redevelopment for statutory environmental audit: Palmers Road, Williams Landing
Summary of works
ESG Environmental (ESG) was engaged by WLTC to conduct a Detailed Site Investigation (DSI) of a portion of the former Royal Australian Air Force (RAAF) Laverton Air Base (Stage 6A). The site was redeveloped for a low density residential land use. The former RAAF Laverton Air Base operated from the 1920s until the early 1990s, when it was decommissioned. Prior to this time, the land of the former RAAF Laverton Air Base was used for pastoral activities. In 2007, the Victorian State Government gave approval for the former RAAF Laverton Air Base to be redeveloped into the new suburb of Williams Landing.
A comprehensive site history desk top study was initially undertaken for the land to identify issues of potential environmental concern at the site. This information was then used to develop a Sampling Quality and Analysis Plan (SQAP) for intrusive investigations.
The intrusive soil investigation was designed to provide site coverage as well as targeting identified former features/activities of potential concern. The investigations involved the collection of soil samples from 57 locations across the site.
The intrusive soil investigation identified elevated metal and benzo(a)pyrene concentrations above adopted criteria for the Audit in some samples of near surface fill. However, these were not found to be significant for the proposed land use.
Fill located in the central portion of the site contained fragments of brick and concrete, ceramic tiles, timber and plastic pipe. The relatively small quantities of this material were not considered to be aesthetically unacceptable for residential (including low density), open space or commercial land use.
However, other inert wastes (including concrete, steel reinforcement, asphalt, coke and slag) covering a small discrete area of approximately 1,100 m² in the south east portion of the site were considered to be aesthetically unsuitable for low density residential land use. However, removal of this material was not considered necessary for the proposed land use at this location (medium density residential). Imported fill that was deemed to be aesthetically unacceptable for low density residential land use was removed from other areas of the site.
Fragments of asbestos containing materials were identified in some areas across the site. These were removed and a clearance certificate provided.
All works were conducted without safety, health or environmental incident or injury.
Project highlights
Client: Williams Landing Town Centre Pty Ltd (WLTC)
Client contact: Mr Richard Poore, Development Manager
Duration: April 2013 – November 2013
Specific issues / problem solving
- Demonstration to the Auditor that the likelihood of unexploded ordnance being present at the site was very low
- Evaluation of the potential for groundwater impacts based on a review of published information on surrounding land that avoided the need for a direct groundwater investigation at the site for the audit
- Liaison with the Client and Auditor to develop an acceptable outcome to the Audit that considered the mixed low and medium density residential land uses.
Key services
- Desktop study investigation
- Development of a Sampling Quality and Analysis Plan (SQAP) for the environmental assessment of the site
- Soil investigations involving sampling at 57 locations
- Statistical and risk based assessment of contaminants of concern
- Removal of impacted soils and wastes off-site
- Removal of Asbestos Containing Materials (ACM) and provision of a clearance certificate
- Reporting for Audit requirements.
Benefits
- Avoidance of a direct groundwater investigation (installation of wells and analysis of groundwater samples) at the site and associated delays to the completion of the Audit
- Provided deliverables (Statement of Environmental Audit with acceptable conditions) within timeframes and to the satisfaction of the client.