Kleinfelder was commissioned to undertake intrusive test pit investigations on over 100 identified debris pits on a 3,000 km2 parcel of land previously used for nuclear weapons testing, and to assess the potential risks to human health, safety, and ecology as a result of large volumes of historical waste.

Assessing The Risks

Working with historical data and the documented incompleteness of previous clean-up activities at the site, Kleinfelder’s risk-based approach, which included the use of unmanned aerial vehicle magnetic surveys, was directed at debris pits previously identified as a ‘high’ or ‘moderate’ risk, allowing for effective use of resources without compromising the assessment of potential risks.

Kleinfelder set out to determine the nature and volume of waste materials and the condition of the debris pits, as well as the extent of soil contamination resulting from the hazardous materials within the pits. A conceptual site model, using the source-pathway-receptor model was developed to identify potential human health, safety, and ecological risks.

Prioritising The Risks

Kleinfelder used the results of the debris pit investigations to develop a Remediation Options Assessment (ROA) and a Debris Pit Risk Register to provide a baseline for future refinement. A semi-quantitative evaluation of potential risks was undertaken, assessing contaminated soils, asbestos, pit aesthetics and physical hazards, all of which are major concerns of the Traditional Owners (Maralinga Tjarutja) to whom the land was returned in 2009.

Project Results

In recognising the mistrust resulting from previous poorly executed and incomplete clean-up activities at the site, Kleinfelder understood the importance of proactive engagement with Traditional Owners. Multi-staged and audience-specific engagement helped build trust and will promote continued engagement as the remediation program is planned and implemented.

To improve Traditional Owner confidence in the robustness of the investigation scope, the SA EPA was proactively engaged in both the planning and execution stages of the project. A Certified Environmental Practitioner was also voluntarily engaged to provide third-party independent input.

Project Details

Location:
Maralinga, South Australia

Owner:
Commonwealth Department of Industry, Science, Energy and Resources (DISER)