E. coli in drinking water

E. coli in drinking water 

What are coliforms? 

• Coliforms are bacteria that are always present in the digestive tracts of warm-blooded 
  animals, including humans.
• They are also found in plant and soil material.
• The presence of coliforms in a water sample does not necessarily mean that your water is 
  contaminated, as some coliforms occur naturally

What is E. coli?

• Escherichia coli (E. coli) is the major species of bacteria in the coliform group.
• It is generally not found growing or reproducing in the environment.
• E. coli is an indicator organism used to detect faecal contamination in water samples.
• The quality of surface waters and collected rainwater is influenced by activities that can 
  shed coliforms (for example, leaking sewage, animal faeces, and dead animals).

What does this mean?

• E. coli being present in a water sample suggests that your water has been contaminated 
  by human and/or animal faecal waste.
• Not all E. coli is pathogenic (disease causing) but the potential to become unwell remains 
  high.
• As E. coli is only an indicator organism, it is not possible to know if any other pathogens 
  are present in your water sample.
• Pathogens include bacteria, viruses, and protozoa.
• It is best to be cautious and assume that there are other pathogens present if you have 
  detected E. coli.

Is there a safe level of E. coli?

• No. The Australian Drinking Water Guidelines requires water to contain less than 1 E. 
  coli/100mL for it to be suitable for human consumption.
• Any concentration of E. coli is considered unsafe for consumption.

What should I do?

• Immediately stop using this water for human consumption until the water can be treated 
  (see more on treatment below).
• Use packaged water (bottled/cask) for human consumption if the water cannot be treated.
• Before using the water source again, it is a good idea to take another sample to ensure 
  that the treatment you have done has been successful and E. coli is no longer present

What is human consumption?

Human consumption includes:

• drinking
• preparing food that will not be cooked (e.g. washing salad items)
• making ice
• making baby formula
• brushing teeth

What can I use the contaminated water for?

Any domestic use that is not mentioned above.

Additional measures to consider:

• use warm water and soap when bathing.
• supervise children when bathing to ensure that they do not drink any water.
• allow dishes to air dry after washing in hot soapy water.
• leafy greens from vegetable gardens should be washed with clean water before eating.

What is a suitable treatment?

• Bringing the water to a rolling boil and being allowed to cool will kill any pathogens and 
  make the water safe to consume.
• You can boil water in a kettle or on a stove top.
• Other treatment options may be available for a medium to longer term solution, depending 
  on your situation.
• Guidance on the use of rainwater tanks provided by the Australian Government 
  Department of Health and Aged Care provides some handy information for those that are 
  serviced by a rainwater tank.
• Discuss treatment options with a licenced plumber who may install a treatment barrier 
  such as Ultraviolet (UV) disinfection.
• Check with your local council to make sure you do not require plumbing permits for any 
  changes to your water collection and storage.

More information

Phone the Department’s Public Health Hotline on 1800 671 738 and ask to speak with the 
State Water Officer during business hours or the Senior Environmental Health Officer 
outside of office hours if your matter is urgent. 

Find out more about Rainwater Tanks