Bore water - when you need to test private, commercial or community-based bores, what you are testing for, how to interpret the results and how to undertake the test.
Bore water is groundwater that has been accessed by drilling a bore into underground aquifers (water storages) and pumping to the surface. Aquifers may contain chemicals and micro-organisms that are potentially harmful. Some of these chemicals are naturally occurring (such as those present in soils and rocks) while others are a result of contamination.
Confined or deep aquifers are usually deep underground which helps protect the water source. These types of aquifers are usually covered by more than 20 meters of rock or clay which act as a natural filter preventing microbial contamination. Unconfined or shallow aquifers are not protected by thick layers, because they are closer to the surface above and are susceptible to both chemical and microbiological contamination.
Deep bores are usually used when the aquifer is 20 meters below the ground.
The microbiological quality of water in deep or confined aquifers is generally very good. The water quality will continue to be good if the bore is properly constructed, protected from entry of surface water and well maintained. Though its microbiological quality may be good, water in these aquifers can contain high concentrations of naturally occurring hazardous chemicals.
Before using a deep bore, obtain a chemical analysis of the water.
Due to shallow bores not being protected by thick layers of soil or clay, shallow bores are not generally recommended as a suitable source of drinking water, particularly in urban areas.
Depending on quality, the uses for deep bore water can include irrigation, livestock watering and clothes washing.
Bore groundwater may be deemed safe for drinking, cooking, filling swimming pools or watering edible plants such as home grown vegetables only after it has been fully tested by a specialist laboratory.
Particularly in urban settings and where mains water is available, the use of shallow bore water is not recommended because of the high likelihood of chemical or microbial contamination. If you have no choice but to use water from a shallow bore, testing requirements will be more intense than for water from a deep bore.
In general, water quality should be assessed with reference to the Australian Drinking Water Guidelines and the Australian and New Zealand Guidelines for Fresh and Marine Water Quality.
The land owner is responsible for the safety aspects of bore water.
It is not always possible to tell if bore water is contaminated. However, changes in appearance or odour can indicate contamination. If this occurs, owners are advised to check the integrity of the bore and to test water quality. If you suspect your water is contaminated, seek advice from your local council Environmental Health Officer.
Bore water quality may change over time. Therefore, after the initial analysis the bore water should be checked every 2 years and monitored by the owner for any undesirable changes in water quality. Shallow groundwater will need to be tested more frequently. More information is available on the Bore water testing page.
When deciding on a location, there are a number of factors that can affect water quality including:
A permit must be obtained before the construction of a bore because:
You can apply for a permit through the Department for Environment and Water.
Avoiding contamination is important because bore water that becomes polluted can be difficult and expensive to treat. Ways you can prevent your bore water from becoming contaminated include:
Failure to properly maintain and protect bores contravenes the requirements of the Environment Protection (Water Quality) Policy.