The bacteria E.coli has been found in Waverley's town water supply.

The water tested positive on Saturday morning for Escherichia coli (known as E.coli) and by late afternoon South Taranaki District Council staff had door-knocked the entire township, advising residents.

They have been told to boil all water used for drinking, brushing teeth and food preparation.

A council spokesman said the "boil water" notice was a precautionary measure while further tests were carried out.