About land contamination
Land contamination is when liquid or solid waste enters soil or groundwater. This can lead to chemical or microbial contamination. Microbial refers to small organisms.
Contamination can be present due to the former use of products such as lead paint or asbestos. Due to long-term multiple uses, contaminants such as PFAS, pesticides and nitrates can also be found in low concentrations across Victoria.
Some regions, such as the Goldfields, have widespread soil contamination. This is due to former mining activities.
Contamination in soil and groundwater can also be common in urban areas, especially in areas that were in the past used for industry or farming.
How contamination can become a risk to human health
Land contamination doesn’t mean there is an immediate risk to human health. Contamination can become a risk to human health when:
- there are ways the contamination can reach people. For example, when contamination moves through land to groundwater or surface water, or when it spreads onto surface soils in areas people might access
- people come in contact with the contamination. For example, through contact with skin, swallowing it, or inhaling dust or vapours.
How EPA assesses human health risks from contaminated land
We use the National Environment Protection Measure (NEPM) Assessment of Site Contamination to assess risks to human health from land contamination.
An investigation may be needed when those in control or management of land believe contamination might be present. We investigate to better understand the former use or storage of chemicals or wastes at the site.
An environmental scientist may then collect samples of soil and water for analysis. We screen the results against set environmental criteria. This allows us to work out whether we need to do further assessment or investigation.
When screening finds soil contamination below the set environmental criteria, risks to human health are low. We don’t do further investigation of the site.
When screening finds contamination above the set environmental criteria, it doesn’t always mean there’s a risk to human health. It means we may need to do a more detailed site assessment. This assessment can help us understand how widespread the contamination is, and the ways people might come into contact with it.
We may also conduct a human health risk assessment. This can help us better understand any potential health risks. It can also help us find out whether we need to take action to reduce the risk of exposure to contamination.
When contamination is found it can usually be managed to reduce potential of exposure and risks to human health. Risks are typically low from plant uptake because we eat a variety of foods.
About land contamination in residential yards
When sites are redeveloped from industrial use to residential, an environmental audit must take place. This lawfully makes sure the land is suitable for its proposed use.
Some houses, however, were built before this law was in place. In addition, products no longer in use, such as asbestos and lead paint, have contaminated the soil at some sites.
This means land contamination in residential areas is common.
How to protect yourself from exposure to residential land contamination
Handling soil is the main way people can come into contact with contaminated land in their yards. This happens when people swallow or breathe in small amounts of soil or dust.
Plants and chickens may also take up some contaminants. This can mean contaminants end up in fruit, vegetables or eggs.
There are ways to reduce your risk of exposure to contamination in residential yards:
- To understand your risk, consider where you live. Lead paint and asbestos contamination is more likely in older houses’ yards. Lead contamination is also more likely in yards closer to major roads. Houses in the Goldfields region may have arsenic in soil from historic mining. Soil in urban centres may have small concentrations of PFAS, heavy metals, petroleum and hydrocarbons. Houses on land formerly used for farming may have pesticide contamination.
- Wear gloves when gardening.
- Brush down shoes before walking back into your home.
- Replace garden soil with clean fill. Consider placing clean fill in areas that house chickens, or where they graze.
- Consider growing vegetables in raised garden beds. These should have hardwood frames, not treated pine frames. Make sure raised garden beds have a layer of material that allows water to drain. Fill raised garden beds with clean soil sourced from off site.
- Wash all vegetables grown in your yard before eating them.
- Wash hands after working or playing in yards, and before eating. This especially applies to children.
About gases from land contamination
Sometimes gases rise from contaminated land and enter buildings. This is called ‘vapour intrusion’. Many factors impact whether this happens, including:
- amount of land contamination
- how close the contamination is to the soil’s surface
- cracks in building foundations or floorboards
- building ventilation.
Vapour intrusion doesn’t often cause ongoing major issues in buildings. When it does, EPA works with the polluter to deal with it and reduce potential risks to human health. We also provide community advice about how to manage any potential health risks.
How land contamination can impact groundwater and surface water
Contamination from land can make its way into groundwater, rivers and creeks. People may use these waterways for drinking water and irrigation, or for recreational activities. For example, fishing and swimming.
Victoria sources most of its drinking water from surface water such as rivers, streams and reservoirs. It’s treated for contamination before it reaches our taps.
In some areas, people use tank water, untreated surface water or groundwater for drinking. Where mains water is available, we advise that people use it instead of these other sources.
Using untreated water for drinking, irrigation or recreation can be a risk to human health. Anyone who wants to use groundwater for these purposes should first have it tested to make sure it's suitable for its intended use.
Those who want to use untreated water for drinking should have it treated to protect against potential contamination. It’s important to re-test water often, as its quality can change over time.
Victoria Unearthed has information about contaminated groundwater locations and restrictions. When Victoria Unearthed doesn’t list groundwater from a location, it doesn't mean the water’s suitable for use. The groundwater may not have been tested.
If you drink or use water from a groundwater bore or river, check it often for chemical contamination. Ask your local water authority how to do this. The Department of Health also has advice on drinking water sources.
How to find out about contaminated land in your area
Victoria Unearthed has information about potential and existing contaminated land. It includes data about:
- groundwater quality
- restricted use zones
- environmental audits
- location of Environmental Audit Overlays. These are tools councils and other planning authorities use to assess land contamination
- former business listings
- past and present landfills.
The following can also help provide information about contaminated land in your area:
- Assessment of soil metal concentrations in residential and community vegetable gardens in Melbourne, Australia
- Map my environment. This is a global citizen science program that provides information on contaminated soils.
What you can do if you’re concerned about land contamination
If you’re concerned about physical or psychological health impacts of land contamination in your area, contact:
- your doctor
- Head to Health.
Where to find more information about land contamination
Sustainability Victoria has information about ways soil can be tested for contamination.
Find out more about groundwater pollution and human health, and contaminated land policy.
Find out more about other public health issues related to pollution and waste
Reviewed 23 May 2021