Pupils at Havelock North schools will return to their classrooms today as the town slowly returns to normality after a gastro bug infected more than 4000 of its residents.

Hawke's Bay Mayor Lawrence Yule says the schools are all open today, more than a week since E.coli was detected in the town's water supply on August 12.

The news follows results from the latest water samples, from Hastings, Flaxmere and Bridge Pa, which all came back clear yesterday afternoon.

The tests were taken from across the network including from the same areas of the water supply that returned suspect results on Saturday.


Hastings District Council chief executive Ross McLeod said the clear results were "expected, but also a huge relief".

It is believed Saturday's suspect results were an anomaly because of sampling irregularities in a small number of samples.

The latest results are consistent with results for the 327 tests taken over the 12 months ending mid-July, which have all been clear.

"What today's results mean is that the Hastings supply, which also provides water to Flaxmere and Bridge Pa, can continue to be considered safe to drink."

Yule says a fuller sense of normality will return to the district when the boiled water notice is lifted.

However, he doesn't expect that to happen until later in the week.

"The quickest thing that will get Havelock North back to normality is the removal of the boiled water notice and that's something that's done by the Ministry of Health and the DHB.

"It will certainly, in my view, be done by Friday because that's when we will have the UV filter all plumbed in and ready and that is being done today," Yule says.

The UV filter, supplied and being installed by Watercare staff today, means it won't matter what bugs are in the water beforehand because once it's been through the filter "it's completely safe".