Underground storage tanks (USTs) are common features on industrial and commercial sites in Western Australia. While often hidden from view, their fuel storage legacies can pose significant environmental risks if they are damaged, old or poorly decommissioned.
At West Soil & Water, our team conduct robust due diligence investigations to identify contaminated land and have vast experience assessing USTs. These services can help you identify and assess UST risks and ensure you meet disclosure obligations under the Contaminated Sites Act 2003.
USTs can corrode with time, allowing fuels, oils and chemicals to leak into surrounding soil and groundwater. As these leaks occur underground, they can go unnoticed for years and contamination might only be detected during redevelopment.
Risks associated with USTs include:
Hydrocarbon contamination of soil and groundwater
Vapour intrusion into buildings, creating health and safety risks
Fire and explosion hazards from accumulated petroleum vapours
Long-term restrictions on land use
Not all USTs carry an equal risk. Those that have been properly decommissioned typically have a much lower risk of ongoing contamination, although they still warrant documentation review.
However, many tanks are simply abandoned and left underground without removal or proper sealing. These pose a significant risk, as corrosion can lead to any of the issues listed above.
To properly protect their investment, it’s important that buyers and developers can distinguish between decommissioned and abandoned tanks. Thorough due diligence investigations are an important step in gaining that clarity.
If you are a buyer or a seller, unaddressed UST risks can affect both the value and usability of the property in question. For buyers there are higher insurance costs, remediation obligations and reduced access to finance. Sellers may experience legal dispute and penalties under WA law.
Comprehensive investigations and soil testing can identify contaminated land and water around USTs. A well conducted assessment will involve:
Historical land use research including examinations of site records, aerial photographs and planning files for evidence of fuel storage or service station use.
Regulatory database checks to review listings on the DWER Contaminated Sites Database.
Site inspections that look for fill points, vent pipes or ground depressions suggestive of underground infrastructure.
Geophysical surveys using non-invasive methods like ground-penetrating radar to confirm the presence and condition of tanks.
If USTs are either suspected or confirmed on your site, you are obliged to assess whether they pose a contamination risk. That may involve:
Soil and groundwater sampling near the tank location.
Testing for hydrocarbons and solvents in accordance with NEPM guidelines and using NATA-accredited laboratories.
Evaluating tank age and construction materials to estimate likelihood of leaks.
Risk assessment to determine potential pathways to human health or the environment.
USTs are a significant contamination risk, but they shouldn’t be assessed in isolation. Rather, you should consider embedding these checks into a wider Preliminary Site Investigation (PSI) or Detailed Site Investigation (DSI).
An integrated approach ensures that tanks are considered alongside other factors like historical land use, nearby activity and groundwater sensitivity. At WSW, we believe a more complete picture provides better safeguards against compliance issues and environmental risk, allowing landowners and developers to move forward with confidence.
At West Soil and Water, our due diligence investigations are structured to ensure regulatory compliance and address the risks of USTs. Our team:
Conduct historical and regulatory reviews to understand past or current storage activities
Complete site inspections to locate hidden infrastructure
Carry out soil and groundwater testing to determine the presence or extent contamination from petroleum and other substances
Construct clear, regulator-ready reports with recommendations for remediation and monitoring
With our assistance, you can identify UST risks early to protect investments, maintain compliance and plan a remediation program that makes sense.
USTs are one of the most common and most expensive sources of contamination in Western Australia. Whilst not always visible, their impacts can be long-lasting and detrimental for property transactions.
West Soil and Water conducts thorough contaminated site testing to ensure UST risks are identified, assessed and managed before they can compromise your project.
For more information or to book an assessment, please get in touch today.
