Reduce your exposure to contaminated land

Before 1989, land converted from industrial to residential use did not have to undergo an environmental audit to make sure it was safe for residential use. This means residential land can be contaminated from historical industrial uses and activities.

Contamination can impact soil, groundwater and surface water.

Examples of common contaminants on residential properties include:

• lead and other heavy metals from past use of lead-based paints, leaded fuels, lead flashing on roofs and other materials with heavy metals
• metals and hydrocarbons from past industrial activities
• historical mining waste
• asbestos cement sheet debris from poor demolition practices or imported soil
• old pesticides and copper chrome arsenate from treated timber
• chlorinated hydrocarbons from consumer and industrial products, such as glues and household cleaners
• contaminated groundwater.

Learn about activities with potential to contaminate land.

Land contamination and your health

Land contamination does not always mean there's an immediate risk to your health. You can live with some contamination safely when the land is appropriately managed.

Contamination can become a risk to your health when:

• the contamination can reach you – for example, when it moves through land to groundwater or surface water, or it spreads to surface soils
• you come in contact with the contamination – for example, through contact with skin, swallowing it, or inhaling dust or vapours.

The risk of harm depends on where, what type and how concentrated the contamination is.

Learn more about how contamination causes harm.

Contamination can be a risk to your health when you're exposed often or at high levels – for example:

• swallowing or breathing in contaminated soil while gardening or playing
• eating unwashed fruits and vegetables from contaminated soil
• eating eggs from chickens foraging on contaminated land
• drinking contaminated tank water, surface water or groundwater
• eating fish from a contaminated dam or waterway
• inhaling indoor vapours from subsurface gases – for example, from leaking underground petroleum storage systems.

If you're concerned you might have contaminated land, the first step is to research how the site was used in the past. When you know your land is contaminated, take steps to protect yourself, others and the environment.

Find out about your property' s past use

To understand your risk of exposure to contamination, consider where you live. For example, lead paint and asbestos contamination are more likely on properties with houses more than 30 years old.

Other location factors to consider include:

• Houses in regions with historical mining may have higher levels of arsenic in the soil.
• Soil in urban centres may have small concentrations of per- and polyfluoroalkyl substances (PFAS), heavy metals, petroleum and hydrocarbons.
• Houses on land formerly used for farming may have pesticide contamination.
• Houses on or near Check Your Groundwater areas have contaminated groundwater.
• Gardens close to major roads are more likely to have lead contamination.
• Houses near contaminated land can be affected by hazardous gases.
• Land where historical waste disposal practices were used, such as incineration, can be contaminated.

Sometimes there are clues that tell you contamination is likely – for example, lead paint on older houses, or soil that is stained or has a chemical odour.

If there are strong clues to indicate contamination, you have a duty to identify and manage it. Learn more about your contaminated land duties and obligations.

Ways to research a site's history

Researching how a site was used in the past can help you identify the potential for contamination. It can also indicate the types of contaminants that may be present.

Using different sources of information can help build a timeline. Some sources include:

Reduce your exposure to contaminated soil

Handling soil is the main way you can come into contact with contamination in your backyard. You can be exposed by getting soil on your body or by swallowing or breathing in small amounts of soil or dust.

Plants and chickens can also take up some contaminants. These contaminants may end up in fruit, vegetables or eggs. The surface of fruit and vegetables can also have soil contamination on it. Risks to people from plant uptake are typically low, because we eat a variety of foods.

To reduce your risk of exposure to contamination in residential backyards:

• Wear gloves when gardening.
• Remove or brush soil from shoes before entering the house.
• Wash hands after working or playing in the garden and before eating and drinking. This especially applies to children.
• Wash all fruit and vegetables grown in your garden before eating them.
• Replace contaminated garden soil with clean soil.

Read more about reducing your exposure to lead contamination in soil.

Vegetable gardens

Consider growing vegetables in raised garden beds. Use hardwood frames, not treated timber. Make sure there's a layer of material underneath to allow water to drain. Fill raised garden beds with clean soil sourced from a reputable source.

Chickens

Keep chickens in pens away from any potential contamination sources – for example, incinerator ash, lead paint, or roofing and guttering materials. Seal pen floors with 30 centimetres of clean soil and top up when needed.

Compost

Manage your compost by only disposing of compostable items. For example, do not compost dryer lint, vacuum cleaner waste, greased paper or plastics. To learn about making great compost, visit Compost is for everyone on the Sustainability Victoria website.

Manage incinerator ash

Before 1980, many households in Victoria burnt rubbish in incinerators. The ash from these incinerators was sometimes used to cover paths and keep down weeds.

This ash can contain toxic compounds from the materials that were burnt, such as plastics and metals, including lead. It's important to limit contact with this ash and manage any residues.

If you notice ash or discoloured soil in your backyard, or if you have an old incinerator, be careful. Do not let children play in the ash material.

If it's a small area and can be easily cleaned up, you can clear it with a shovel. Wear a dust mask and protective clothing. Put the ash in plastic bags in your general rubbish bin.

For large areas of ash or discolouration, contact your local council for advice.

Manage contamination in water

Contamination from land can make its way into groundwater and surface water such as rivers, creeks and dams. This can happen in many ways, including from:

• chemicals spilled into or near stormwater drains
• chemicals spilled into the soil seeping into the groundwater
• chemicals polluting groundwater reaching surface waters
• run-off from contaminated land to surface waters, including dams
  
• leaking underground petroleum storage systems
• poorly maintained or disused onsite wastewater management systems.

Contamination in groundwater and surface water is a problem when you use the water for drinking, irrigation or recreational activities. It can also harm plants and wildlife that live in the natural environment.

Contamination can also lead to vapour intrusion. This is when hazardous gases travel underground and into buildings.

Dams, bores and tanks

For drinking water, some areas rely on:

• tank water
• untreated surface water, such as dams
• groundwater (bore water).

Using untreated water for drinking, irrigation or recreation can be a risk to your health.

Dams on private property capture run-off from rainfall for storage. Run-off can contain chemicals and pollutants from nearby areas, such as farms, industry or contaminated sites. This can contaminate your dam.

To make sure untreated water is safe for use, test it for contaminants. Do this before using it for vegetable gardens, livestock, swimming or drinking.

Learn more about managing contaminated groundwater and using groundwater safely.

To learn more about untreated water and protecting your health, visit Water quality in tanks, bores and dams on the Better Health Channel.

Septic systems

Whenever liquid waste is stored or treated, there's a risk of polluting the groundwater.

Onsite wastewater management systems, including septic tank systems, can cause groundwater contamination. Poorly installed or maintained systems can be a risk to human health and the environment, especially older systems. Learn more about managing an onsite wastewater system.