Watercare issued a boil water notice for 7800 properties across Hillsborough, Mt Roskill, Royal Oak and Three Kings last night after a routine water sample returned a positive E. coli result. Photo / Michael CraigWatercare issued a boil water notice for 7800 properties across Hillsborough, Mt Roskill, Royal Oak and Three Kings last night after a routine water sample returned a positive E. coli result. Photo / Michael Craig

Watercare workers could be seen inspecting the reservoir atop Big King Reserve this morning.Watercare workers could be seen inspecting the reservoir atop Big King Reserve this morning.

Which areas are affected?

Watercare has issued a boil water notice this evening for Hillsborough, Mt Roskill, Royal Oak and Three Kings. Image / WatercareWatercare has issued a boil water notice this evening for Hillsborough, Mt Roskill, Royal Oak and Three Kings. Image / WatercareWatercare has issued a boil water notice this evening for Hillsborough, Mt Roskill, Royal Oak and Three Kings. Image / WatercareWatercare has issued a boil water notice this evening for Hillsborough, Mt Roskill, Royal Oak and Three Kings. Image / Watercare

What do people in affected areas need to do?

Watercare is operating public water tankers for affected residents until the issue of potential contamination is resolved. Photo / Michael CraigWatercare is operating public water tankers for affected residents until the issue of potential contamination is resolved. Photo / Michael Craig

What is E. coli and are there any symptoms?

A 3D illustration showing Escherichia coli, E. coli, colonising parts of the intestine. 
Image / Getty Images
A 3D illustration showing Escherichia coli, E. coli, colonising parts of the intestine.
Image / Getty Images