Check Your Groundwater Area (CYG Area) is an area, site or property where groundwater is known to be contaminated, usually as a result of previous industrial activity. This means the quality of the groundwater may not be suitable for some uses. It may be harmful to human health and the environment.
Note: Victoria Unearthed has not been updated and still refers to ‘Groundwater Quality Restricted Use Zones’ (GQRUZ) rather than CYG Areas.
A CYG Area exists where sufficient information is provided about the level and type of groundwater contamination. A CYG Area can be placed on a site during investigation or after clean up of groundwater contamination. Even when attempts have been made to clean up the groundwater at the affected site, full clean-up may not be possible - as it is often difficult to remove 100 per cent of groundwater pollution. It also may be impractical to clean up groundwater to the level needed to restore it to its original condition. EPA identifies CYG areas to help with the awareness and management of contaminated groundwater.
A CYG Area includes a brief summary of a site’s history and a list of unsuitable uses for the groundwater.
EPA previously called CYG Areas ‘Groundwater Quality Restricted Use Zones’ (GQRUZ’s) and has been managing the identification of CYG Areas and GQRUZ’s since their introduction in 2002 and updates its information on an ongoing basis.
CYG Area data has been included in Victoria Unearthed as it provides valuable information about groundwater contamination identified across the state.
For more information on data quality, see Data quality: accuracy and reliability where Data Quality Statements are available for download.
Note: Some audit reports are Commercial-in-Confidence and cannot be published.
If you have any questions about a CYG Areas, please contact EPA.
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.
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 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.
Note: Victoria Unearthed has not been updated and still refers to ‘Groundwater Quality Restricted Use Zones’ (GQRUZ) rather than CYG Areas.
CYG Areas appear as light-blue dots and light-blue outlined shapes with diagonal lines. The shapes may only be visible when you zoom in on the map to a scale of 1:250,000 or less. Shapes show a site boundary or area covered by a CYG Area and the dots are the site locations.
The CYG Area should only have an impact if you are accessing or considering accessing groundwater.
Refer to ‘Living in or near a CYG Area on EPA’s website.
EPA applies CYG Areas and they can be removed or amended under certain conditions.
Contact EPA’s Environmental Audit Unit (environmental.audit@epa.vic.gov.au) if you feel a CYG Area should be changed.
EPA has information available on its website about CYG Areas.
EPA: Land and groundwater pollution
EPA Publication 2001: Guidance for the cleanup and management of contaminated groundwater
Page last updated: 22/12/25