Groundwater is water that collects or flows under the surface of soil. It fills spaces in soil, sand, clay and rocks. Groundwater quality varies across Victoria.  In some areas, groundwater is not suitable for human use.

Drinking untreated groundwater can lead to illness. This includes gastroenteritis, known as 'gastro'.

About groundwater and your health

Although most of Victoria’s drinking water is sourced from surface water such as rivers, streams and reservoirs, some areas rely on groundwater. Even where mains water is available, some people use private wells to access groundwater. 

Using untreated groundwater for drinking, irrigation or recreational purposes can be a health risk. EPA recommends groundwater is tested to make sure it is suitable for its intended use. 

Water quality risks should be understood before using groundwater, especially for:

  • drinking
  • cooking
  • cleaning teeth
  • bathing
  • other personal uses.

EPA recommend that those who want to use groundwater for drinking consider treating it first to protect against potential chemical and microbial contamination. It’s important to re-test groundwater regularly, as its quality can change over time. Mains water is reliable and treated to a level that's safe for human use.

Victoria Unearthed has information about contaminated groundwater locations and quality restrictions. When groundwater from a particular location is not listed on Victoria Unearthed, it doesn't mean it's suitable for use. The groundwater may not have been tested.

To find out about accessing water from a residential groundwater bore, contact: 

Refer to the Department of Health's guidelines on groundwater for more information.

Contact a doctor about any health concerns after accessing or drinking groundwater. 

How groundwater can become contaminated

A range of sources can contaminate groundwater, including:    

Natural rock and soil can also contaminate groundwater. Contaminants may include:

About EPA's role when groundwater is contaminated

EPA identifies potential groundwater contamination through a range of programs, including Victoria’s environmental auditing system.  

Contaminated groundwater must be cleaned up or managed. When sites play a part in groundwater contamination, EPA requires site assessment, clean up and management.  

It’s not always possible for sites to completely clean up groundwater contamination. In those cases, EPA may: 

  • put in place a groundwater quality restricted zone to track the contamination and formally communicate issues with groundwater use
  • require management of contamination based on the potential risk of harm 
  • stop certain activities where they may worsen groundwater contamination  
  • make periodic checks of whether further groundwater clean up is possible. For example, when new technology becomes available. 


Find out more about other public health issues related to pollution and waste

About mercury in your home

Airborne dust and your health

Climate, weather and public health

Contaminated illegal drug labs and public health 

Contaminated land and public health

Environmental public health

Environmental public health: EPA’s role

How to clean up mercury spills in your home

How to manage hazardous chemical waste and asbestos in your home

Trichloroethylene and your health

Your health and the environment: learn and take action

Reviewed 1 November 2023