Underground storage systems
Underground storage systems (USS) are most often associated with the storage of petroleum products and are also commonly referred to as underground petroleum storage systems (UPSS) or underground storage tanks (UST).
Other hazardous substances including waste and chemical products may be stored in underground storage systems. Petrol stations typically have several USS at each site. USS are one of the major sources of soil and groundwater contamination due to the potential for leakage of the product they were designed to contain.
The resulting contamination may present a potential or actual risk to human health and the environment. This can impact on the suitability of the site or for its current or proposed land use, and may affect surrounding properties.
Design, installation and management
As of 1 January 2020 all petrol stations are required to hold an EPA licence (authorisation). Petrol stations must ensure their USS design, installation and management practices meet the conditions set out in the licence.
Where a licence condition has not been imposed, the EPA recommends that all USS system design, installation and management should comply with:
- Australian Standards 1940–2017: The storage and handling of flammable and combustible liquids
- Australian Standard 4897–2008: The design, installation and operation of underground petroleum storage systems
The standards are means of ensuring that all reasonable and practical measures are taken in regard to complying with the Environment Protection Act 1993 and the Environment Protection (Water Quality) Policy 2015.
Other statutory authorities such as SafeWork SA also have conditions and requirements that must be adhered. It is the owners responsibly to ensure they comply with all statutory obligations in regards to USS.
Removing underground storage systems
Underground storage systems are a major source of soil and groundwater contamination. The EPA recommends removing all USS that are no longer being used for their originally intended purposes as soon as reasonably practicable.
The removal of the USS should be undertaken in accordance with Australian Standard 4976-2008: The removal and disposal of underground petroleum storage tanks.
A suitably qualified and experienced site contamination consultant should be engaged to assess the site to determine if there has been any impact to soil or groundwater, and to undertake remediation if necessary in order to verify the suitability of the site for the intended use.
An independent site contamination auditor may be required to review the work completed to ensure the site is suitable for its intended use, depending on the land use proposed and the nature and extent of site contamination.
The assessment and remediation of sites containing USS must be undertaken in accordance with Guidelines for assessment and remediation and Guideline for assessment of underground storage systems (see 'Further information').
The assessment and remediation of sites containing USS must be undertaken in accordance with:
- Guidelines for assessment and remediation of site contamination
- Guideline for assessment of underground storage systems
If you have any questions please contact the Site Contamination Branch on (08) 8204 9934