A Practical Guide for Builders, Developers and Site Managers
If suspected asbestos is uncovered during excavation, stop disturbing the affected area, establish an exclusion zone and have the material assessed before excavation resumes.
Finding asbestos does not necessarily mean the entire site needs to shut down or undergo large-scale remediation. The appropriate response depends on what has been found, whether it is friable or non-friable, how it occurs within the soil, how much of the site may be affected and what work is proposed next.
For construction and development projects in NSW, an unexpected asbestos find can involve both work health and safety requirements and contaminated land management considerations. Getting the initial response right is important because continuing to excavate can spread asbestos-containing material through otherwise unaffected soil and substantially increase the scale of the problem.
1. Stop Work in the Affected Area
If material suspected of containing asbestos is encountered during excavation:
stop excavation and other activities that could disturb the material;
keep personnel and plant out of the affected area;
establish an exclusion zone using barriers and warning signage;
minimise dust generation and unnecessary handling; and
activate the project's unexpected finds procedure, where one is in place.
SafeWork NSW recommends stopping work, minimising disturbance and restricting access where asbestos may have been disturbed. Excavation that involves, or is likely to involve, disturbance of asbestos is also classified as high-risk construction work, requiring an appropriate Safe Work Method Statement. SafeWork NSW
The objective at this stage is not to start removing material. It is to prevent the find from becoming a larger contamination issue while its significance is determined.
2. Confirm Whether the Material Contains Asbestos
Suspect material should be assessed by a suitably competent asbestos professional.
Common unexpected finds during excavation include:
asbestos cement sheeting and fragments;
asbestos cement pipes;
demolition rubble containing asbestos-containing materials;
buried building waste;
asbestos insulation or lagging;
friable or highly degraded asbestos-containing material; and
soil containing dispersed asbestos fibres or fragments.
Visual identification alone cannot reliably confirm asbestos. SafeWork NSW states that confirmation at a workplace requires laboratory analysis by a NATA-accredited laboratory of a sample collected by a competent person. SafeWork NSW
A Licensed Asbestos Assessor may be appropriate, particularly where friable asbestos is suspected or Class A asbestos removal work is likely. However, an LAA is not legally required simply to collect every asbestos sample. The specific licensing requirements depend on the work being undertaken. SafeWork NSW
3. Determine Whether It Is an Isolated Find or Asbestos-Contaminated Soil
Once asbestos is confirmed, the next question is usually more important:
How does the asbestos occur within the site?
A single fragment uncovered within otherwise natural soil is very different from demolition fill containing asbestos fragments across a development footprint.
The assessment may need to establish:
the source + distribution + depth + condition + likely extent of the asbestos.
For a simple, isolated occurrence, inspection and controlled removal may be sufficient.
Where asbestos appears to be associated with historical fill or buried demolition material, further investigation may be required to determine whether asbestos is present more broadly across the soil profile.
SafeWork NSW's guidance distinguishes between surface fragments and asbestos buried within the soil. More complex or buried occurrences require a site-specific assessment and should be managed using contaminated-site assessment and management principles. SafeWork NSW
This is where an unexpected asbestos find can move from being primarily an asbestos removal issue to a contaminated land issue.
4. Update the Conceptual Site Model
For development sites, an unexpected asbestos find should also be considered in the context of the site's existing contamination assessment.
For example, the find may indicate:
Source: historical demolition waste or uncontrolled fill containing asbestos.
Pathway: excavation, mechanical disturbance or exposed soil generating respirable fibres.
Receptors: construction workers, future site users, neighbouring properties or the surrounding environment.
If asbestos was not previously identified as a contaminant of potential concern, the site's Conceptual Site Model may need to be updated and the significance of the new information assessed.
The investigation should then be proportionate to the uncertainty created by the find rather than automatically expanding into a large grid-based investigation.
5. Decide Whether Remediation or Management Is Required
Once the nature and extent of the asbestos are sufficiently understood, an appropriate management response can be developed.
Depending on the project, this could involve:
localised removal of isolated asbestos-containing material;
excavation and off-site disposal of asbestos-contaminated soil;
controlled hand-picking or screening of suitable non-friable material;
further delineation of affected fill;
remediation under a Remediation Action Plan;
retention beneath an engineered containment or capping system; or
longer-term management where asbestos remains safely in situ.
The approach should be based on the type of asbestos, exposure potential, proposed development and future land use, rather than assuming excavation and disposal is always the only option.
NSW EPA guidance recognises that asbestos in or on land needs to be assessed and managed in the context of current and future occupants and workers. Where contaminated land remediation is undertaken, the objectives and management approach should be documented and the completed remediation appropriately validated. EPA NSW
6. Engage the Correct Asbestos Removalist
Licensing requirements depend primarily on whether the asbestos is friable or non-friable.
A Class B asbestos removal licence is required to remove more than 10 m² of non-friable asbestos or ACM.
A Class A asbestos removal licence is required for the removal of friable asbestos. Class A removalists can also remove non-friable asbestos. SafeWork NSW
Asbestos in soil can make the calculation less straightforward than removing intact sheets from a building. If the material is distributed through fill, damaged, degraded or potentially friable, specialist advice should be obtained before determining the appropriate removal methodology.
7. Does SafeWork NSW Need to Be Notified?
Finding asbestos does not, by itself, mean a five-day notification must immediately be lodged with SafeWork NSW.
The notification requirement relates to licensed asbestos removal work.
SafeWork NSW requires notification at least 5 calendar days before licensed asbestos removal work starts where the work involves:
more than 10 m² of non-friable asbestos; or
friable asbestos.
The licensed asbestos removalist generally manages that notification. Emergency provisions exist where qualifying asbestos removal must occur immediately. SafeWork NSW
If an actual asbestos exposure incident has occurred, separate SafeWork considerations may also apply and specialist advice should be obtained.
8. Does Council Need to Be Involved?
This depends on the project.
For a site subject to a Development Application, complying development approval, remediation approval or specific contamination conditions, an unexpected asbestos find may need to be reported to the Principal Certifier, Council or other approval authority.
The site's consent conditions and existing environmental documentation should therefore be reviewed.
An unexpected find may trigger requirements for:
additional contamination assessment;
an amendment to an existing Remediation Action Plan;
a new remediation or asbestos management strategy;
validation reporting; or
implementation of an Unexpected Finds Protocol.
This is one reason an unexpected find should not be treated solely as a contractor WHS issue. It may also affect the documentation relied upon to establish the site's suitability for development.
9. Does the NSW EPA Need to Be Notified?
Not every asbestos discovery must be reported to the NSW EPA.
Under the Contaminated Land Management Act 1997, landowners and persons responsible for contamination have a duty to notify the EPA where the circumstances meet the statutory duty-to-report requirements.
Whether that threshold is reached depends on the nature, extent and significance of the contamination and should be considered against the EPA's Duty to Report guidelines. EPA NSW
For many development sites containing localised historical asbestos in fill, the matter can be managed through the planning and contaminated land process without direct EPA regulation.
However, this should be determined from the actual circumstances rather than assuming asbestos contamination is either automatically reportable or automatically exempt.
10. Manage Asbestos Waste Correctly
Once asbestos or asbestos-contaminated soil is excavated for disposal, it becomes subject to NSW waste requirements.
Under the NSW EPA Waste Classification Guidelines, asbestos waste is classified as Special Waste. Other contamination within the soil may also result in additional waste classifications that must be considered. EPA NSW
Asbestos-contaminated soil should be kept damp, contained during transport and disposed of at a facility that can lawfully receive asbestos waste. Disposal dockets should be retained as part of the project records. EPA NSW
Where more than 100 kg or 10 m² of asbestos waste is transported within NSW, EPA waste-tracking requirements apply. EPA NSW
This is particularly important on larger remediation projects because the disposal documentation becomes part of the evidence used to demonstrate where the excavated material went.
11. Clearance Is Not the Same as Contaminated Land Validation
This distinction is important on asbestos-in-soil projects.
A clearance inspection and clearance certificate relate to the asbestos removal area and the WHS requirements applying to licensed asbestos removal work.
For Class A work, the clearance inspection and certificate must be undertaken by an independent Licensed Asbestos Assessor. For Class B work, they may be undertaken by an independent competent person or LAA. SafeWork NSW
A contaminated land validation assessment asks a broader question:
Has the remediation achieved its objectives, and is the land suitable for the proposed use or management scenario?
Depending on the project, validation can involve:
inspection of excavation surfaces;
confirmation that visible ACM has been removed;
validation sampling;
review of disposal dockets;
confirmation of remedial extents;
assessment against the adopted remediation criteria; and
preparation of a Site Validation Report.
On some projects both a WHS clearance certificate and contaminated land validation report may be required. They serve different purposes and should not be treated as interchangeable.
Can Work Restart Immediately After the Asbestos Is Removed?
Not necessarily.
Before excavation resumes, the project team should be satisfied that:
the immediate asbestos hazard has been cleared + the contamination issue has been adequately addressed + any required validation has been completed + the unexpected finds and construction controls have been updated.
If asbestos remains elsewhere on the site, the remaining material may need to be incorporated into the project's management documentation so it is not inadvertently disturbed later in the works.
Why Unexpected Finds Procedures Matter
The best time to decide what happens when asbestos is uncovered is before the excavator finds it.
SafeWork NSW has specifically identified the absence of unexpected finds procedures as an issue during construction inspections involving earthmoving plant. SafeWork NSW
For sites with historical fill, former structures, demolition history or uncertain land-use history, an Unexpected Finds Protocol should establish:
when work stops → who is contacted → how the area is isolated → who assesses the material → how results are communicated → what is required before work resumes.
This can prevent a relatively small asbestos find from being spread over a much larger area by excavation, stockpiling or truck movements.
What Should You Do If Asbestos Is Found During Excavation?
The response should be proportionate, but the sequence is generally straightforward:
Stop disturbance → isolate the area → confirm the material → assess its extent and significance → determine the appropriate removal or management strategy → complete required clearance and validation → then recommence excavation.
The important part is avoiding the temptation to simply remove the visible fragment and continue digging before understanding whether it represents an isolated item or evidence of a broader asbestos-contaminated fill layer.
Asbestos in Soil Assessment and Remediation Support
Confluence Environmental provides asbestos-in-soil assessment, contaminated land investigation, remediation planning, asbestos air monitoring, clearance inspections and validation services across NSW.
Our contaminated land and hazardous materials capabilities are integrated within the same project team, allowing unexpected asbestos finds to be considered from both the WHS asbestos and contaminated land perspectives.
Where asbestos is encountered during excavation, we can assist with determining the immediate controls, investigation requirements and appropriate pathway for remediation or management.