A water expert says the likelihood of another bacterial infection in Martinborough's water supply is low, now that a new agency has taken charge.
The South Wairarapa District Council issued a boil-water notice this month after E coli was detected for the second time in as many months.
A boil water notice was issued in February shortly before one of the district's most popular events, the Martinborough Fair, and lasted for more than two weeks.
A mineral in the town's water means it cannot be treated to kill germs, in the same way that is done in neighbouring towns.
Wellington Water will now provide the council with its water management services.
Jim Graham from Water New Zealand, a not-for-profit group promoting the sustainable management of waterways, reckons it has the expertise to prevent further problems with the supply.
"Wellington Water has a very good record with supplies they run and that record should carry over to South Wairarapa," he said.
Lower Hutt water clear of E coli
Follow up testing of the Naenae reservoir in Lower Hutt has come back clear of E coli.
Wellington Water issued a notice that testing on Friday indicated the presence of E coli at Naenae reservoir. However, follow-up samples were clear.
During the next three days, Wellington Water will test the water at various locations to ensure it is safe.
Residents are being told to expect the taste and odour of chlorine in their drinking water over the next few days.