About groundwater

Groundwater is water that collects or flows beneath the soil surface, filling the porous spaces in soil, sand, clay, and rocks. Groundwater is accessed using a bore.

Depending on the quality of groundwater, it can be used for a variety of purposes, such as:

drinking water
irrigation of crops (including domestic gardens) and parks
livestock water supply
commercial and industrial purposes
recreational purposes (such as filling swimming pools)
geothermal heating and energy.

Drinking water and groundwater

Although most of Victoria’s drinking water supply is sourced from surface water (rivers, streams and reservoirs), around 50 towns across Victoria are either partially or totally reliant on groundwater as their main source of drinking water. In the towns where groundwater is used as a source of drinking water, the water is treated to a drinking water standard by the relevant water business, in accordance with the requirements of the Safe Drinking Water Act 2003 and the Safe Drinking Water Regulations 2015.

In some parts of rural Victoria, private groundwater bores are used as sources of drinking water. Where households use groundwater as their source of drinking water, regular management and maintenance should be undertaken. The Department of Health has guidance on groundwater.

All businesses and community groups that rely on a private water supply for drinking (potable) water must take all reasonable precautions to ensure the water is safe for human consumption. Businesses that use water for:

food preparation (including cleaning), or
to supply water to customers (e.g. accommodation / caravan parks etc.),

must, by law, ensure that the water used is potable.

The Department of Health has guidelines that can assist food and accommodation businesses to ensure that their water supply is safe for food preparation and human consumption.

Groundwater contamination

Groundwater contamination is usually the result of poor environmental care and practice, particularly in heavily populated industrial areas. Contamination of groundwater is identified through a range of activities and programs that EPA regulates, including Victoria’s environmental audit system.

Once contaminated, groundwater is very difficult to clean up and usually becomes a long-term environmental legacy. The GED requires people undertaking activities that may pollute groundwater to minimise the risk of this occurring.

Poor practices that have resulted in groundwater contamination include:

poor storage, or disposal, of liquid to land
leaking underground storage tanks.

Over time these contaminants have mixed with the groundwater.

At surface level, contamination can occur when rain mixes with chemicals, which can then move through the soil and into the groundwater. Activities that can contaminate land and groundwater are covered on EPA’s webpage What causes contamination.

It may be impractical to clean up groundwater to the level needed to restore it to its original condition. A good analogy is a sponge dipped in oil and then squeezed out and cleaned – there is still going to be residual oil present in the sponge.

Similarly, in the environment, it is often difficult to remove 100 per cent of groundwater contamination. In these cases, EPA may accept that groundwater has been cleaned up as much as practicable and that, subject to appropriate ongoing management or restriction on its use, further clean up is not required.

Groundwater clean up that involves a discharge to an aquifer (e.g. the injection of remedial chemicals) will need to comply with Permissions under the Environment Protection Regulations 2021.

Groundwater quality restricted use zones (GQRUZ)

A GQRUZ (groundwater quality restricted use zone) is an area identified by EPA where there is known groundwater contamination. GQRUZs are usually informed by an environmental audit, but may also be identified when EPA becomes aware of the contamination through other information.

A GQRUZ is used to show that there are quality restrictions on how the water could be used without further treatment.

Under certain circumstances, EPA requires individuals or organisations undertaking clean up of groundwater to notify potentially impacted offsite property occupiers or owners of possible impacts to the groundwater. You can read more about what you need to do if you have contaminated land (including groundwater) on the webpage Understanding your contaminated land duties.

Rural water corporations, who license the construction of bores and groundwater use, may also refer to information on GQRUZs to inform licensing decisions.

Refer to Victoria Unearthed to see specific GQRUZs.

You can also visit Visualising Victoria’s Groundwater to look at GQRUZs spatially, with other information on groundwater.

GQRUZ data

Datasets for groundwater quality restricted use zones (GQRUZs) can be downloaded from DELWP’s data portal.

If you have problems accessing the data, contact EPA at contact@epa.vic.gov.au or call 1300 372 842.

Disclaimer: Any information contained in a GQRUZ dataset is intended to be used only as a guide and should not be relied upon as being either complete or accurate. EPA does not verify the accuracy of all information contained in a GQRUZ dataset. If you have an interest in a particular piece of land, location, site or property you should make your own enquiries of relevant authorities.

EPA does not accept any responsibility for any claims, loss or damage of any kind whatsoever arising out of any person’s reliance on any information that either:

is contained in or omitted from GQRUZ dataset, or
arises out of the inclusion or exclusion of any land, location, site or property on a GQRUZ.

Living in a GQRUZ

If you are living in area with a GQRUZ and using bore water for a purpose listed with a quality restriction, then you should stop immediately and familiarise yourself with the quality restrictions. The quality restrictions identify potential risks to human health or the environment.

Contact EPA’s Pollution Hotline on 1300 372 842 for further information.

Regardless of whether or not there is a GQRUZ affecting your property, rural water corporations recommend regular testing of bore water used for domestic and/or stock purposes to ensure it is fit for purpose and does not present a risk to human health.

Victoria Unearthed

Victoria Unearthed has information about potential and existing contaminated land. It includes data about:

groundwater quality
groundwater quality restricted use zones (GQRUZ)
environmental audits
EPA’s priority sites, where we have issued notices relating to contamination
location of ‘Environmental Audit Overlays’. These are tools councils and other planning authorities use to assess land contamination
historical business listings
past and present landfills.

Groundwater quality restricted use zones on Victoria Unearthed

Bore water testing

Bore owners are responsible for making sure the bore water they use is fit for the intended use.

It is important for users of groundwater to understand the risks associated with the intended use of the groundwater supply. Prior to use, groundwater may need to be disinfected to remove harmful microorganisms and treated to remove chemicals, algal toxins or radiological contaminants that maybe present.

To get your water tested, you should consult a suitably qualified environmental consultant or a NATA (National Association of Testing Authorities) accredited chemical analysis testing laboratory. These can be found by searching online or by speaking to your water authority.