A primary school in Central Otago is taking precautions after high levels of arsenic were found in the water supply of the kindergarten next door.
Children at Hawea Kindergarten have been asked to bring bottled water while further testing is carried out.
A spokesperson for owner Kidsfirst Kindergartens, based in Christchurch, said arsenic was found naturally in local bores.
The spokesperson said the kindergarten did not know how bad the problem was but was taking precautions while waiting for more tests, due on Thursday.
Anna van Riel, who has a child at Hawea Flat School, said parents were sent an email last night from the school also telling children to bring bottled water while it tested its own water supply.
Mrs van Riel sent her daughter to school today with a water bottle and told her not to drink from the water fountain.
"It's an easy precaution to take," she said.
"As a parent, you feel concerned, but I know that they're a very vigilant school and kindergarten."
The maximum acceptable level of arsenic in water supplies is 0.01mg per litre.
Last week E coli was detected in a private water supply on the outskirts of Masterton and about 100 residents supplied by the Fernridge scheme were warned to boil their water.
A member of the scheme's management committee, Grant Allen, said it wasn't required to notify residents over a first test which recorded low bacterial levels but after the Havelock North campylobacter outbreak, it had decided to take immediate action.
More than 5000 people had gastrointestinal illness when Havelock North's drinking water became contaminated by E coli and campylobacter in August.