About 2000 homes in the Shirley, Bexley, Wainoni and New Brighton are affected.
The presence of E.coli in the water supply was confirmed on Saturday morning after water samples were taken on Friday from the Keyes pump station in Rawhiti Domain.
The pump station provides water to these eastern suburb areas.
All water used for drinking, food preparation, utensil washing, brushing teeth or making ice should be boiled until further notice.
“The boil water notice will remain in place until laboratory tests confirm the water is safe to drink,’’ Christchurch City Council's reticulation and maintenance manager Tim Drennan said.
“Bringing water to the boil is sufficient to kill bugs. If you cannot boil water, treat it by adding one teaspoon of household bleach per 10 litres of water and leave for 30 minutes.’’
Mr Drennan said the cause of the contamination was not yet known.
“Staff are working to identify the cause of the contamination but in the meantime we will be flushing the network to ensure all traces of e-coli are removed.
"The boil water notice will remain in place until laboratory testing confirms the water is safe to drink.’’
What is the health concern?
Although waterborne diseases are extremely rare, they can be serious. The risk is higher for infants, the elderly, and persons with immune deficiency disorders. The E.Coli bacteria may not be harmful, but there is a small risk.
What can I do?
Disinfect water used for drinking (including pets), cooking, brushing teeth, rinsing contact lenses, shaving and making ice. Water does not need to be disinfected for bathing, showering, or laundry. Be careful not to drink water while you’re in the shower.
What happens if I feel ill?
It’s very unlikely that you are feeling ill because of E.Coli contamination, but please call or visit your doctor for advice. We’re recommending boiling water as a precaution only.
- Source: Environment Canterbury
