Managing contaminated soil is a necessary byproduct of waste disposal. This is because soil contamination essentially occurs from poor waste management systems.
The basis for this comes as a result of soil pollution. Like all pollution, it is the result of production. What we do with the left overs matter as these left overs are waste.
Environmental management teams work alongside experienced waste management teams like Cleanway to both minimise the level of contaminated land and to safely dispose or restore the site.
These basic principles are the basis of contaminated soil disposal. This blog outlines some of the eleven common management methods.
When to engage a licensed contractor
Our first major recommendation is that you should not dig, move, or treat contaminated soil yourself.
This is true even if you believe something might not be contaminated. We highly recommend that you assume contamination and avoid touching anything.
Engage a licensed provider like Cleanway immediately if you notice:
- Visible staining, chemical odours, or sheens after rain
- Soil impact from a spill, tank leak, or historical site use
- Unexpected waste uncovered during construction or excavation
- Regulatory triggers: waste classification required, groundwater risk, or work near sensitive receptors
Note that contaminated sites can be more dangerous to human health than they appear. Soil contaminants are often, meaning that the negative health risks might be the first time that people know something is wrong.
Additionally, groundwater contamination is by nature difficult to spot and detrimental in effect. Calling Cleanway’s team before it is too late is of utmost importance.
11 methods of managing contaminated soil disposal
Each method below includes a overview, typical use cases, and key considerations.
The right approach depends on contaminant type, soil profile, depth, groundwater, timeframe, access, and EPA conditions.
Additionally, if you’re interested in some of the management choices made, this blog by Evoro provides a detailed outline of Soil Disposal Management.
1) Soil Contamination excavation and off-site disposal
Overview: Remove contaminated soil and transport it to a licensed treatment facility or hazardous waste landfill.
Best for: High contaminant concentrations, tight timeframes, or when on-site treatment isn’t feasible.
- Requires waste classification, licensed transport, and chain-of-custody documentation
- Fast risk reduction but may involve significant cartage and tipping costs
- Controls dust, odour, and runoff with covers, misting, and lined trucks
2) Containment (capping and barriers)
Overview: Isolate impacted soil using engineered barriers (geofabric, liners, clay caps) or vertical barriers (cut-off/slurry walls).
Best for: Deep or diffuse impacts where removal is impractical.
- Prevents contaminant migration and exposure pathways
- Requires long-term monitoring and maintenance plans
- Often combined with drainage controls and vapour barriers
3) Bioremediation (in situ and ex situ)
Overview: Use microbes to break down organic contaminants; can be performed in place (in situ) or after excavation (ex situ biopiles).
Best for: Petroleum hydrocarbons, some solvents and pesticides.
- Lower carbon footprint; supports circular-economy outcomes
- Requires the right conditions (oxygen, nutrients, pH, temperature)
- Timeframes vary from weeks to months; monitoring is essential
4) Soil remediation and washing
Overview: Physically separate contaminants from soil using water and surfactants/chemical agents, then treat the wash water.
Best for: Heavy metals and certain organics in granular soils.
- Reduces contaminant mass rapidly; generates a smaller hazardous stream
- Less effective in high-clay soils without pre-treatment
- Requires on-site plant or transfer to a specialist facility
5) Thermal treatment
Overview: Apply heat to desorb or destroy contaminants (thermal desorption or incineration).
Best for: Volatile and semi-volatile organics (e.g., solvents, fuel residues).
- High removal efficiency with robust emission controls
- Energy intensive; suitable for defined, high-impact hotspots
- Executed by licensed specialists under strict safety protocols
6) Chemical oxidation (ISCO)
Overview: Inject oxidants (e.g., persulphate, hydrogen peroxide) to break down organics in situ.
Best for: Petroleum hydrocarbons, PAHs, some chlorinated solvents.
- Targets hard-to-reach zones without excavation
- Often delivered via wells in multiple passes
- Requires hydrogeological assessment and reagent selection
7) Soil stabilisation and solidification
Overview: Add binders (cement, lime, pozzolans) to immobilise contaminants and reduce was feeding into water (a process known as leaching in the technical world)
Best for: Heavy metals and inorganic contaminants.
- Improves geotechnical properties for safe handling or disposal
- Does not destroy contaminants; long-term monitoring may apply
- Can enable on-site reuse under engineered controls
8) Land and soil treatment (landfarming)
Overview: Spread impacted soil in controlled beds and stimulate biodegradation by aeration and nutrient addition.
Best for: Petroleum-contaminated soils at suitable sites.
- Cost-effective with low equipment intensity
- Requires approved land, odour/dust controls, and regular sampling
- Timeframes typically months to 1–2 years, depending on load
9) Soil vapour extraction (SVE)
Overview: Apply vacuum to pull vapours from the vadose zone for above-ground treatment.
Best for: Volatile organic compounds (VOCs) in unsaturated soils.
- Highly effective for shallow, permeable soils
- Often combined with air sparging for groundwater interfaces
- Requires power, monitoring, and off-gas treatment
10) Recycling and reuse
Overview: After treatment, soils meeting criteria can be reused in non-sensitive applications (e.g., backfill, sub-base).
Note that we often favour recycling in waste management due to its environmental benefits.
Best for: Projects targeting circular-economy outcomes.
- It reduces disposal volumes and haulage impacts
- Requires documented verification against reuse standards
- Traceability and quality control are always essential
11) Polyencapsulation
Overview: We encapsulate contaminants within a polymer matrix to prevent release.
Best for: Some persistent or difficult-to-treat contaminants with low tolerance for leaching risk.
- Provides long-term containment where destruction isn’t feasible
- Design must consider durability and monitoring
- Typically used in combination with other controls
How to choose the right option
While our process for choosing the best option for dealing with soil contamination is highly dependant on the site in question, our general process is mapped out below:
- Contaminant profile: Organics vs inorganics, mixtures, and concentrations
- Soil and hydrogeology: Grain size, clay content, groundwater depth and flow
- Depth and access: Urban constraints, utilities, overheads, and traffic
- Timeframe: Project schedules may drive excavation or accelerated treatments (as timeframes often vary once projects begin)
- Regulatory approvals: EPA requirements, permits, and stakeholder engagement with relevant Australian licensing bodies like the EPA.
- Waste classification: Correct coding supports disposal and tracking
- Traceability: Chain of custody, transport certificates, and reporting
- Sustainability goals: Opportunities for on-site treatment and reuse
Cleanway’s compliant, end-to-end process
Cleanway solves hazardous and complex waste problems quickly and safely — protecting people, assets and the environment. Our process keeps you compliant and your project moving.
1) Site assessment and classification
We review history, undertake sampling, and classify waste to EPA standards. You get a clear risk picture and practical options.
2) Immediate risk control
We implement containment measures (covers, barriers, runoff controls) to protect workers, neighbours, and waterways.
3) Licensed collection and transport
Our trained team loads, documents, and transports contaminated soil using EPA-licensed vehicles with full chain-of-custody reporting.
4) Treatment, disposal and reporting
We direct material to the most suitable treatment or disposal pathway and provide transparent close-out reporting to support audits.
Quick example: keeping a food & beverage facility online
When a food manufacturing client uncovered hydrocarbon-impacted soil during maintenance, Cleanway mobilised same day. We contained the area, sampled and classified the waste, and executed targeted excavation with lined transport to a licensed facility. Operations resumed safely within 24 hours, supported by documentation for the client’s EHS audit.
FAQs: contaminated soil disposal (Australia)
What is contaminated soil?
Soil containing chemicals, metals, or other pollutants at levels above health or environmental criteria. Common sources include tanks, workshops, historical landfills, and spills.
Who regulates contaminated soil?
State and territory Environment Protection Authorities set requirements for classification, transport, treatment, and disposal. Your local planning authority may also apply conditions.
How long does remediation take?
From days (excavation and off-site disposal) to months (bioremediation) depending on contaminant type, concentrations, site access, and approvals.
Can treated soil be reused?
Yes, if it meets applicable reuse criteria and is supported by verification sampling and documentation. Cleanway provides compliance reporting to support reuse decisions.