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, industrial purposes and recreational purposes (such as filling swimming pools).

The majority 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 2005.

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, it may need to be treated prior to use.　

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. Water used for drinking or for cleaning of tableware or appliances used in food preparation must be potable by law.

The Department of Health maintains guidelines that can assist food businesses to ensure that their water supply is safe for food preparation and human consumption. These guidelines are available from: www.health.vic.gov.au/foodsafety/bus/safe.htm.

A GQRUZ (groundwater quality restricted use zone) is an area where, following an environmental audit, there is remaining groundwater pollution, usually as a result of previous industrial activity.

A GQRUZ is identified when attempts have been made to clean up the groundwater and EPA determines that restrictions should remain on how the water can be used without further treatment.

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

Polluted groundwater is usually a long-term environmental legacy.

Poor practices that have resulted in groundwater pollution include the poor storage, or disposal, of liquid to land and leaking underground storage tanks, which with time have become mixed with the groundwater. At surface level, pollution can occur when rain mixes with chemicals, which can then move through the soil and into the groundwater.

The most common activities that have polluted or have the potential to pollute groundwater, unless properly managed, include:

• waste disposal activities (for example, landfills, septic tanks, waste-water storage, irrigation and ash ponds)
• bulk chemical storage (for example, underground petroleum storage tanks at service stations, refineries)
• application of agricultural chemicals
• accidental chemical spills (such as from drycleaning)
• chemical manufacturing and storage facilities
• electroplating
• service stations, auto and other metal workshops
• intensive agriculture
• explosives manufacturing
• tanneries
• gasworks
• car or textile manufacturers
• filled quarries
• bootmakers.

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 pollution. In these cases EPA may accept that groundwater has been cleaned up as much as possible and that, subject to appropriate ongoing management or restriction on its use, further cleanup is not required.

Depending on the quality of groundwater, it can be used for a variety of purposes, such as drinking water, irrigation (crops, parks or domestic gardens), livestock water supply, industrial purposes, and recreational purposes (for example, filling swimming pools). Where pollution remains (a GQRUZ) the groundwater may not be able to be used for one or more of these purposes.

The details of specific GQRUZs are available via EPA’s interactive web tool.

Victoria’s environmental audit system is one of the most stringent systems in Australia.

When a GQRUZ has been identified, the auditor responsible for overseeing the cleanup must consider any potential risks to human health and the environment and make recommendations to EPA. We will then determine whether the site requires further cleanup or ongoing controls to be put in place to ensure human health and the environment are protected.

If you are living in one of these GQRUZ zones and using bore water for a restricted use then you should stop immediately and familiarise yourself with the restrictions. The restrictions identify potential risks to human health or the environment.

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

Rural water corporations recommend regular testing of bore water used for domestic and/or stock purposes to ensure it is fit for purpose.

While information about GQRUZs has previously been included in environmental audit reports available on EPA’s website, there has been no single, simple source of information on these zones. EPA has consolidated existing information in a centralised location so people can find information about groundwater pollution.

EPA requires individuals or organisations undertaking cleanup of groundwater to notify potentially impacted offsite property occupiers or owners of possible impacts to the groundwater.

EPA also provides information on GQRUZs to rural water corporations, who license the construction of bores and groundwater use.

Yes – pollution of groundwater is an offence under the Environment Protection Act and, therefore, where there is sufficient evidence, EPA can prosecute. However, sometimes prosecuting the polluter for groundwater pollution is difficult because it is often the result of industrial activity that may have occurred a long time ago, and in some instances identifying the polluter is no longer possible.

The Environment Protection Act does make provisions for the occupier or landowner to pursue compensation from known polluters for any costs they may incur for complying with an EPA notice. There is no reason why this course of action can not be pursued if the groundwater pollution source is known.

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

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 the telephone directory or by speaking to your water authority.

Please call EPA’s Pollution Hotline on 1300 EPA VIC (372 842). If you would like to talk to an expert in this area, you can do so by contacting this number.