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

When mains water is available, it should be used instead of groundwater. Mains water is reliable and treated to a level that's safe for human use.

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

Accessing untreated groundwater for drinking, irrigation or recreational use can be a health risk. Anyone who wants to use groundwater for these purposes should first have it tested. This is to make sure it's suitable for its intended use. 

Anyone using groundwater should first find out about its quality. Water quality risks should be understood before using groundwater for:

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

Those who want to use groundwater for drinking should have it treated to protect against potential chemical and microbial contamination. It’s important to re-test groundwater regularly, as its quality can change over time.

Victoria Unearthed has information about contaminated groundwater locations and 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: 

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

We find 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, cleanup and management.  

It’s not always practicable for sites to clean up groundwater within regulated time limits. In those cases, EPA: 

  • puts in place a groundwater quality restricted zone to track the contamination and restrict groundwater use
  • requires a practicable cleanup, which can include managing contamination in line with potential risk 
  • stops certain activities where they may worsen groundwater contamination  
  • makes periodic checks of whether groundwater cleanup is now practical. 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 16 March 2021