Carterton issued third boil water notice, days after the last one lifted

The re-discovery of E.coli in Carterton's water supply has left the council scratching its head.

It's issued a third boil water notice - after saying on Sunday it was confident the problem was solved.

It's a not-so-Good Friday for the Wairarapa town after 16 days of boiling tap water last month - it's deja vu for residents who say it's about time the council sorted it out. 

Especially Carolyn Watkins - who spent a week in bed with a stomach bug and believes the tap water is to blame

She told Newshub she was "violently sick" a fortnight ago.

"I brought it to the attention of the council and they had had issues with the water."

She's disappointed the boil water notice was lifted on Sunday, only to put it back in place on Thursday.

"I was told it'd been tested and was clear - but it obviously wasn't. I really think they're not aware of what is actually contaminating it."

Five days ago the council was confident a faulty valve was the culprit. But with a low-level E.coli test result on Thursday, it's back to square one.

Carteron mayor Greg Lang says it's "very frustrating" for businesses during a busy holiday period.

Carterton residents will have to use this council water for at least another seven days while they wait for experts to track down the source of contamination.

"Hopefully they find it and we find a possible cause," says Lang.

And until the mystery is solved, filling up water bottles will be a regular routine for many locals.