Haumoana School's water has been cleared for drinking after an indicator test for E. coli resulted in school closure yesterday.

It was open today with a disconnected water supply from its private bore, which can be reconnected after overnight testing showed its water safe to drink.

"Our water sample result has been returned and we are pleased to advise that samples taken yesterday from tank and tap comply with the requirements of the Drinking-Water Standards for New Zealand 2005," principal Jane Gallen said.

"Our tank was treated yesterday as a precaution to ensure we could be open today and we will continue to test daily for a week then resume our regular testing schedule unless otherwise advised."

Following the failed indicator test and in light of the Havelock North campylobacter outbreak via drinking water, that affected more than 4000 people, Hastings District Council yesterday announced chlorination would be introduced to council-owned water supplies to Haumonana, Te Awanga and Parkhill.

Chief executive Ross McLeod said there was a heightened concern regarding water quality and council-supplied water for the whole district would be chlorinated "for the foreseeable future".

"We are taking a precautionary approach, chlorinating the water so people can be confident the water is safe to drink," he said.

"We know that some people do not like the taste or smell, but at this time we believe that treating the water is the most responsible thing to do."

Mrs Gallen said occasional unusual water test results were "the reality of country living".

"We are grateful we continue to avoid the "gastro-bug" and I am sure we will rise to the challenge of having treated water in the weeks ahead. It will taste better eventually."