Case Study: When an Asbestos Clearance Certificate Is Not Enough
Understanding the Difference Between WHS Clearance and an Asbestos in Soil Investigation
Unexpected asbestos finds during civil works can create significant confusion for contractors, developers and site owners, particularly where stakeholders assume that an asbestos clearance certificate “closes out” the issue entirely.
In practice, an asbestos clearance certificate and an asbestos in soil investigation (“ASI”) serve very different purposes.
A recent industrial remediation project undertaken by Land Risk Environmental highlights why understanding this distinction is critical from both a contaminated land and WHS perspective.
The Scenario
During remediation and underground petroleum storage system (“UPSS”) removal works at an industrial site in western Sydney, fragments of suspected asbestos-containing material (“ACM”) were identified within a stockpile generated from excavation works.
The material was subsequently classified as Special Waste (Asbestos) in accordance with the NSW EPA Waste Classification Guidelines and removed from site by a licensed asbestos removal contractor.
Following removal:
a visual asbestos clearance inspection was undertaken
a clearance certificate was issued for the former stockpile area
an asbestos in soil investigation was completed to assess whether the asbestos impacts were localised or representative of broader site contamination.
While these two deliverables were related, they addressed fundamentally different risk questions.
What Does an Asbestos Clearance Certificate Actually Confirm?
An asbestos clearance certificate is primarily a workplace health and safety (“WHS”) document associated with asbestos removal works.
In NSW, the clearance process generally sits within the framework of:
Work Health and Safety Act 2011 (NSW)
Work Health and Safety Regulation 2017 (NSW)
SafeWork NSW asbestos removal requirements.
The purpose of the clearance certificate is to confirm that:
asbestos removal works were completed appropriately
no visible ACM residue remains within the inspected area
the removal area is suitable for reoccupation at the time of inspection.
Importantly, a clearance certificate is generally limited to:
the defined asbestos removal area
accessible surfaces
visual inspection outcomes.
It does not typically:
assess wider site contamination
determine whether asbestos impacts exist elsewhere onsite
delineate the extent of contamination
assess long-term contaminated land risk
From a WHS perspective, the key question is:
“Has the asbestos removal area been adequately cleaned and visually cleared for reoccupation?”
What Does an Asbestos in Soil Investigation Assess?
An asbestos in soil investigation is a contaminated land assessment undertaken to determine:
whether asbestos contamination is present within soil or fill materials
the nature and extent of contamination
whether impacts are localised or widespread
potential exposure risks associated with the proposed land use
whether remediation or management is required.
Unlike a clearance inspection, an ASI involves:
intrusive investigation
systematic soil sampling
laboratory analysis
contamination delineation
conceptual site model assessment
risk-based interpretation.
The investigation is typically undertaken with reference to:
National Environment Protection (Assessment of Site Contamination) Measure 2013
WA Department of Health Guidelines for the Assessment, Remediation and Management of Asbestos-Contaminated Sites in Western Australia (2021)
NSW EPA contaminated land guidance.
From a contaminated land perspective, the key question becomes:
“Is asbestos contamination present within the soil profile and, if so, what is the extent and associated risk?”
Why the Distinction Matters
One of the most common misconceptions encountered during remediation projects is the assumption that an asbestos clearance certificate automatically demonstrates that:
the site is free from asbestos contamination, or
no further contaminated land assessment is required.
In reality, the two documents address different regulatory and risk frameworks.
In this project:
the clearance certificate confirmed the successful removal and visual clearance of the stockpile area from a WHS/reoccupation perspective
the ASI demonstrated that the asbestos impacts were limited in extent and not representative of widespread contamination across the broader fill areas.
Together, the documents allowed the unexpected asbestos find to be closed out from both:
a workplace asbestos removal perspective, and
a contaminated land risk perspective.
Key Takeaway for Developers and Contractors
Where asbestos is identified during earthworks or remediation, it is important to understand whether the issue requires:
asbestos removal clearance
contaminated land assessment
or both.
A clearance certificate alone may not satisfy planning, environmental or contaminated land obligations where there is potential for broader asbestos contamination within fill or soils.
Likewise, an asbestos in soil investigation does not replace the need for appropriate WHS asbestos removal controls and clearance processes.
Early engagement with contaminated land and asbestos specialists can significantly reduce project delays, regulatory uncertainty and disposal risks when unexpected asbestos impacts are encountered during construction or remediation works.
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