NSW Health recommends that surface water from farm dams, rivers and creeks should not be used for drinking, cooking or personal hygiene (including cleaning teeth and bathing) without testing and appropriate treatment, including disinfection. It is very important to ensure that the water your family drinks is safe.
Surface water includes water obtained from dams, streams and rivers. Surface water may be easily contaminated by animal and humans wastes and chemicals from run-off. Surface water may also be at risk of algal blooms.
Surface water may be acceptable for non-potable uses such as washing clothes, irrigation, gardening, toilet-flushing, but we recommend that water used for bathing is at least disinfected before use.
Surface water can be contaminated with:
Some surface water may also be affected by hardness, salinity and other naturally occurring chemicals.
NSW Health warns that heavy rainfall and flooding increases the risk of contaminated water which could contain disease causing micro-organisms, chemicals or algal blooms, entering surface waters such as rivers and creeks. Blue-green algae may cause skin irritation. Water quality may be affected during drought as flow and the amount of water is reduced.
The amoeba Naegleria fowleri has been identified in warm surface water. Infections are very rare but are often fatal. Infection may occur when contaminated water goes up into the nose (including when people swim, dive or fall into water, or when children play under sprinklers or with hoses). Any water body that seasonally exceeds 30 degrees Celsius or continually exceeds 25 degrees Celsius can support the growth of Naegleria. Users should seek specialist advice on the use of chlorination to control Naegleria, which cannot survive in water that is clean, cool and chlorinated.
Users should check for contaminated land notices issued by the NSW Environment Protection Authority (EPA) or other authorities for sites that may be located near or upstream of surface water sources.
Information on surface water quality including information on algal alerts is available from WaterNSW.
Residents are urged to ensure they are aware of the quality of the water source they are using. To avoid or minimise water quality problems in surface water:
The Public Health Act 2010 requires premises that serve the public or employees and have a private water supply (including surface water, groundwater or rainwater) used for drinking, food preparation or personal hygiene, to have and comply with a quality assurance program. For more information see the NSW Health's Private Water Supply Guidelines.
NSW Health recommends that users of surface water be familiar with the quality of their water. This can be done by testing the microbiological, chemical and radiological quality of the water. Water used for household purposes such as drinking, food preparation and personal hygiene (including cleaning teeth/oral hygiene and bathing) should meet water quality guidelines to protect you and your family's health. Refer to private water supply testing service and DPI Water quality for more information on water quality and treatment.
Surface water contamination can move from the original source of contamination over a wide area or distance. Contamination can persist for variable lengths of time depending on water movement and the natural biological, chemical, and physical processes that help cleanse surface water.
The risks to health will depend on the type and concentration of contaminants in the surface water and also how often, for how long and in what ways people are exposed to the water (e.g. drinking, inhalation, or skin contact).
Sometimes there is not enough information to assess the health risks from contaminated surface water. Where risks are known, public warnings are issued. Residents in areas where contamination is likely (e.g. areas of previous industrial use) should not use surface water for other domestic purposes, such as irrigation of fruit and vegetables or use in spas and swimming pools.
An alternative to using surface water is to collect rainwater. A properly maintained rainwater tank can provide good quality water. For more information on maintenance and safe use see Rainwater tanks.