Groundwater is water that pools or flows beneath the surface, filling porous spaces in the earth.
Groundwater is a finite resource. Like surface water, it is allocated under the Water Act 1989. Groundwater includes water of varying quality from bores, spear-points (shallow installations), springs or wells. Groundwater can be used for a range of purposes.
Water quality from deep bores is generally suitable, but shallow bores can be contaminated.
Groundwater can be contaminated by a range of sources, including:
- agricultural run-off (such as pesticides and fertilisers)
- industrial run-off and pollution
- seepage from rubbish tips
- polluted stormwater
- chemical spills
- contaminated surface waters
- high levels of naturally occurring chemicals (such as arsenic).
Groundwater quality restricted use zones
The State Environment Protection Policy (Groundwaters of Victoria) provides the statutory framework for managing groundwater contamination in Victoria.
Under this policy, some areas are classified as groundwater quality restricted use zones (GQRUZ). This means that groundwater in these areas is not suitable for use because of past contamination, such as from industrial use or poor waste management.
If you live in a GQRUZ but do not use groundwater, the GQRUZ does not affect you.
More information on GQRUZ can be accessed from the Environment Protection Authority Victoria website.
Managing health risks
Groundwater is not as reliable as reticulated (mains) water. If mains water is available, it should be used for drinking and preparing food instead of groundwater.
Groundwater should only be used if the bore is well maintained and the water quality is suitably high. Water from shallow bores is not recommended due to the chance of contamination.
Nitrates in groundwater can pose a risk to bottle-fed babies. If you are considering using groundwater to prepare infant formula, you should contact your maternal and child health nurse or family doctor first.
Landowners should complete a water supply management plan and regularly assess water quality risks.
Make sure the bore is protected from:
- surface run-off
- channel water
- irrigation water
- leakage from sewer pipes
- greywater drainage
- shallow underground seepage.
Make sure that the bore is properly cased, with an above-ground well-head. If possible, store drinking water in an above-ground tank rather than an underground tank.
Make sure that drinking water plumbing is completely separate from all other plumbing or pipe systems, and that all pipe joints are properly sealed.
Key water agency websites have information on bore licensing and maintenance, including Southern Rural Water, Goulburn-Murray Water and Grampians Wimmera Mallee Water.