What is site contamination?
Site contamination is an important environmental, health, economic and planning issue and can have implications for land owners and occupiers, developers, councils, planning authorities, government and local communities.
Site contamination is generally historical in nature. South Australia, like other urbanised cities in the world, manages site contamination issues that are the direct result of past practices.
In South Australia, site contamination is defined within Section 5B of the Environment Protection Act 1993 and is most often caused by:
- petrols, oils, solvents, degreasers and other substances used in manufacturing
- industrial sites such as gasworks, drycleaners, timber preservation and tanneries
- agricultural chemicals, weedicides and pesticides/termiticides
- waste products such as ash (which were often buried).
Site contamination is often detected during testing required as part of the planning approval processes associated with the subdivision, development or redevelopment of a parcel of land.
Only suitably qualified and experienced persons should undertake assessment and remediation. In South Australia the Environment Protection Act 1993 establishes a legislative framework for the management of site contamination.
Dealing with the legacy of site contamination and managing its impacts can be a complex and challenging issue.
Every situation is different. When chemical substances associated with potentially contaminating activities are found, site-specific investigations should be undertaken to determine the extent, nature and level of risk associated with each case. Following investigations, which could be ongoing, remediation may be necessary to treat, contain, remove or manage the contamination to eliminate/prevent the risk or potential risk of exposure.
What legislation applies?
The Environment Protection Act 1993 defines that site contamination exists at a site if:
- Chemical substances are present on or below the surface of the site in concentrations above the background concentrations (if any), and
- The chemical substances have, at least in part, come to be present there as a result of an activity at the site or elsewhere, and
- The presence of the chemical substances in those concentrations has resulted in —
a. actual or potential harm to the health or safety of human beings that is not
trivial, taking into account current or proposed land uses, or
b. actual or potential harm to water that is not trivial, or
c. other actual or potential environmental harm that is not trivial, taking into account current or proposed land uses.
‘Water’ is defined in the Environment Protection Act 1993 and includes surface waters, groundwater, water introduced to an aquifer and any artificially created body of water or stream for public use or enjoyment.
When did the current legislation come into operation?
Some selected definitions and the requirements for truth in reporting came into effect on 10 December 2007.
Provisions relating to the accreditation of auditors came into effect on 20 November 2008.
Remaining provisions came into operation on 1 July 2009.
There may be site contamination, but is there a risk to the public?
For site contamination to exist, all three of the following elements must exist:
- a source (eg contaminated groundwater)
- a pathway (eg use of bore water)
- a receptor (eg residents).
There are many ways that site contamination can be managed – there is no ‘one size fits all’ approach - and each case is assessed individually. The determination of whether site contamination exists depends on a range of factors, including whether or not the current or proposed land use is considered sensitive, such as homes or schools.
Variables depend on the types of chemicals found, the concentrations of the chemicals and where they were found. The EPA assesses each report it receives from independent auditors and determines the potential impact, what steps may need to be taken to manage this potential risk – and how quickly.
Chemicals behave differently, so while some chemicals may require many years of exposure before posing a health risk, others may present a more immediate risk.
In some cases the way to minimise and manage risk is to remove one of the three elements – for example, if the pathway is removed then the risk to the public is reduced or removed. An example would be managing contaminated groundwater by ensuring that there are no bores in operation within the contaminated area accessing that water source.
Sometimes sites can be cleaned up by removing the source, such as removing contaminated soil, or by putting physical barriers between the contamination and people, thus removing the pathway. However, sometimes the nature of contaminants, their location or their extent, may mean that a complete site clean-up is not practicably possible and the contamination may need to be managed on an ongoing basis.
Who is responsible?
Responsibility for site contamination is assigned in accordance with the 'polluter pays' principle.
Accordingly the original polluter has liability for contamination caused on and off the source site regardless of when it was caused. This means the person who caused the site contamination is responsible for implementing and funding the assessment, meeting the costs of an independent site audit by an accredited site contamination auditor and any subsequent management, containment or clean-up of the site. This may also include meeting the costs of and undertaking communication with the affected community.
Site contamination is often historical in nature, and the person or company who caused the site contamination may no longer exist or may not be the same person or company who currently own or occupy the site. If it is not possible to find that person or company, then liability passes to the site owner. However, the site owner's liability may be limited to only the owner's site and liability is dependent on the owner's knowledge of the site contamination at the time of purchase.
A person can gain or divest liability for site contamination through a transfer of liability for site contamination agreement.
A person can also gain liability by causing site contamination through changing the land use.
A person who owns a site has obligations of reporting site contamination of groundwater to the EPA.
If you are an owner of site that has site contamination, there may be a need to engage a site contamination auditor. For more information on the audit system.
Where do instances of site contamination mainly occur?
In the vast majority of cases, site contamination occurs in locations where industrial activity is centred – or has historically been based and a change in the nature of land use is proposed.
Contamination is often detected as a result of land zoning changes via planning and development processes that require site evaluations to occur as part of land sale and application for a new use for the parcel of land.
Why does it take so long for sampling, testing and results to be available?
The process of carrying out the assessment of site contamination can be lengthy and will depend on the nature of sampling and testing required. Samples of soil, groundwater or vapour need to be collected in the field and then transported to laboratories for analysis.
The laboratories then need to perform the analysis and perform checks on the test results prior to their release. Once received, test results need to be reviewed and interpreted by health and risk assessment specialists.
The SA Department of Health does not recommend the use of any groundwater obtained from a well or bore for any purpose unless it has been tested and shown to be safe for that use.
Click here to view information on current site contamination investigations.
What is the role of the EPA?
The EPA influences and regulates human activities to protect and restore the environment using the tools and powers available under the Environment Protection Act 1993 (the Act) and the Radiation Protection and Control Act 1982. There are a series of guidelines and codes of practice that assist others in determining the measures required by the EPA to protect, restore and enhance the environment. The EPA is governed by a Board with members from business, community, environmental management, and local and state governments.
The EPA’s vision is to work towards a clean, healthy and valued environment that supports social and economic wellbeing for all South Australians now and in the future. Environmental goals include ensuring that land and water is fit for purpose.
Where site contamination is identified, the EPA has powers under the Act to require a person to determine the cause and extent of the contamination. The EPA regulates the site contamination management system, ensuring responsible parties meet their obligations, including, when applicable, communicating with potentially affected stakeholders such as the neighbouring community.
The EPA is also responsible for administering the site contamination audit system which accredits expert and independent professionals under the Act as site contamination auditors. Copies of audit reports must be sent to the EPA and these are available to the public to search online.
There are severe penalties for companies and auditors who do not comply with requirements. Please refer to the information sheet on the overview of the site contamination audit system.
When does the EPA tell the community about the discovery of site contamination?
Notifications are made available on the EPA’s Public Register soon after they are received, and an online index is available.
As soon as a risk to public health is confirmed, the EPA and/or the responsible party directly advises the affected community.
Who does the EPA work with to manage site contamination in the interests of public health?
The EPA has a long-standing relationship with SA Health, which has expertise to assess public health risk when site contamination is confirmed. This includes expertise to determine what types and concentrations of chemicals may pose a risk to human health.
Does the EPA carry out testing for site contamination?
Not usually. This is because the EPA is the regulator and ensures responsible people undertake appropriate testing and ongoing monitoring for any contamination that presents a public health or environmental concern.
Testing and monitoring is normally undertaken by site contamination consultants and is reviewed by the EPA’s site contamination experts or the auditor.
The only exception to this is when there is sufficient evidence to require access to people’s homes to undertake air/vapour testing. Whenever this is required, the EPA’s scientific staff will talk to residents and home owners direct and then undertake the testing.
Companies which have caused the contamination, or the current owners of the contaminated site, are responsible for the costs incurred in testing and monitoring.
What causes groundwater contamination?
There are many chemical substances that can impact on groundwater. The impacts range from an unpleasant taste to imminent health hazards.
While contaminants are often described using their chemical names, it is often more helpful to understand what sort of industrial activity uses the chemicals, solvents, degreasers and pesticides that require close monitoring and management – it provides some relevance and de-mystifies the source of contamination.
In many cases, managing this contamination is a legacy of past practices – and may not have been caused by the current site owner.
The types of activities which can cause contamination are listed on our index of site contamination groundwater notifications. The types of activities are:
|Potentially Contaminating Activities – index list of S83a notifications (as at March 2012)||Percentage|
|Service station/motor repair||32.1|
|Liquid organic chemicals (solvents)||18.9|
|Waste and recycling||7.2|
|Infrastructure (road/rail/electrical etc)||2.6|
Does a notification always mean groundwater contamination exists?
Notifications can be for either potential or actual groundwater contamination.
Sometimes, subsequent research and testing proves that there is no groundwater contamination despite earlier concerns. Sites may also exist on the index even though they have been subsequently remediated, and in these instances there will be reports for this site on the public register that demonstrate site contamination containment or management.
Most sites are under active management and pose no threat to neighbouring communities. Petrol stations are a good example of this – fuel companies are active in managing their sites to ensure best practice environmental management and update their equipment and underground storage tanks to ensure no leakage into the ground.
Why does it seem as though there are more cases of groundwater site contamination?
The Environment Protection Act 1993 was enhanced on 1 July 2009, legally requiring property owners, occupiers, consultants and auditors to advise the EPA of any site contamination that affects or threatens underground water (Section 83a).
Prior to this new provision, there was no requirement to notify the EPA. Under the 2009 change, the property owner and/or the site contamination auditor or consultant are now legally required to notify the EPA in writing about the existence of the contamination as soon as they become aware of it.
This amendment has been a vital improvement to protect public health. Being notified of potential contamination in this way enables the EPA to adequately assess the risk to the public, in collaboration with SA Health, and to ensure responsible parties take action to manage and clean-up contaminated sites.
What are the steps the EPA takes when it receives a notification of actual or potential groundwater contamination?
Public health is a paramount consideration at every step in the process and if a risk of harm to people is identified, a community engagement process to inform the potentially affected community is activated immediately.
When notified that actual or potential site contamination (soil and groundwater) exists in an area, the EPA’s first step is to:
- make a preliminary assessment, particularly to ensure exactly which properties/Certificate of Titles are affected,
- directly advise utilities and local and state government authorities so that they can be aware when planning any excavations in the area, and
- place a copy of the notification on the EPA Public Register, the EPA website and a public notice in the local media to advise that a notification has been received.
The EPA writes to the site owner outlining their responsibilities and obligations and assesses the notification to determine what further action may be needed. It also starts an ongoing dialogue with relevant parties, including SA Health, in determining the level of risk that may be posed to people and the environment. This process continues throughout each of the next steps.
Once the potential site contamination has been verified, the EPA needs to ascertain whether the contamination poses a risk to the public. This requires further investigation to determine the nature of the contaminant, such as:
- What are the concentration levels of the chemicals found?
- Are they able or likely to move (ie via groundwater or air)?
- If movement is possible or likely, where might it move to and how quickly?
This assessment is usually conducted by a site contamination consultant or auditor employed by the site owner or developer – who may not have been the person or company who originally caused the contamination.
As contamination usually relates to industrial use, the site owners are usually companies, who then engage consultants to undertake testing. The EPA may require that the process be supervised by an independent and accredited site contamination auditor and reports must be submitted to both the site owner and the EPA. The consultant and auditor’s fees are paid by the site owners.
The assessment process typically continues in an outwards direction from the source of contamination to determine its boundary and extent. This may occur in a series of stages, which can take several months for each stage.
It can include a range of activities such as modelling to determine the direction and rate of groundwater flows, as well as drilling of monitoring bores to sample groundwater. This is a complex and specialised process and is only undertaken by qualified professionals. If not done properly, there are risks that the contamination may not be adequately identified, or may be spread further.
Once the outer boundary of contamination is determined, the EPA considers a management plan with the site owner for managing the now defined contamination. This typically includes ongoing monitoring requirements and independent site audits, implementation of environmental guidelines relevant to the site and codes of practice to which the company must adhere.
If at any stage in the process the EPA becomes aware of test results or other information indicating a potential risk to public health, the EPA consults with SA Health. If real and actual risk to the community has scientific basis, either the responsible party and/or the EPA and/or SA Health communicates directly with affected residents and neighbourhoods.
If the results of the assessment indicate that there is a need for further testing inside private homes, then, with the informed consent of the owner and/or occupier, that testing will be conducted by the EPA.
A flowchart diagram showing how site contamination is assessed and managed is available.
View the EPA’s policy on public communication of site contamination issues.
Why are some underground storage systems a problem?
Underground storage systems (USS) are most often associated with the storage of petroleum products (commonly referred to as underground petroleum storage systems or UPSS). Other hazardous substances, including waste products, may also be stored in underground tanks.
USS are one of the major sources of soil and groundwater contamination due to the potential for leakage of product to the environment.
The resulting contamination may represent, or potentially represent, risks to human health and the environment and impact on the acceptability of the site, or nearby sites, for their current or proposed use.
Removal of old or unused USS
The EPA recommends removing all USS that are no longer being used for their originally intended purposes (ie storage of petroleum products or other hazardous materials) as soon as reasonably practicable.
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 recommend remediation if necessary in order to verify the suitability of the site for the intended use.
An independent 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 issues.
Guidelines for USS design, installation and management
The EPA is in the process of developing a code of practice on the design, installation and management of USS.
In the interim, the EPA recommends compliance with the Victorian EPA Guidelines on the Design, Installation and Management Requirements for Underground Petroleum Storage Systems as a 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 2003.
Further information on the assessment of sites containing USS can be obtained from the EPA Guidelines for assessment of underground storage systems.