TA head of regulatory Steve Taylor said last night the situation in Queenstown was complex.
“The source of the outbreak is still unconfirmed, but on the information available at the moment there is a material risk as it relates to drinking water.
“We also know that the Two Mile water treatment plant is non-compliant, creating a risk of contamination that is not being appropriately managed.”
TA was “working constructively, and with urgency”, with the council to resolve the issue.
“The lack of a protozoa barrier at the Two Mile water treatment plant creates a serious risk to public health, demonstrated by confirmed cases of cryptosporidiosis affecting consumers in the Queenstown drinking water supply distribution zone served by the plant,” Taylor said.
The compliance order required the council to keep its boil water notice in place until particular changes were made.
The council had two water treatment plants which supplied about 44,708 consumers.
The Two Mile and Kelvin Heights treatment plants took water from Lake Wakatipu and distributed it to different supply zones.
The Two Mile plant had no treatment for protozoa.
The boil water notice must remain in place until either treatment for protozoa was in place and operating, or an alternative supply of safe drinking water was made available.
The Kelvin Heights plant had treatment for protozoa, but information recently provided by the council had raised some doubts about whether this barrier was working, Taylor said.
The boil water notice would be lifted when the council satisfied TA its plants were performing effectively.
The Water Services Act 2021 required drinking water suppliers to ensure the drinking water they provided was safe.
The drinking water quality assurance rules which came into effect on November 14 required the type of drinking water supply in place in Queenstown to have a protozoa barrier.
Taylor said TA was aware of about 190 supplies in New Zealand — serving about 13 per cent of the population — that had similar source water characteristics to the Queenstown supply and had reported no protozoa barrier at the treatment point.
Te Whatu Ora Health New Zealand National Public Health Service Southern continued contact tracing yesterday to search for the infection’s source.
Rees Hotel chief executive Mark Rose said the lack of water treatment filters was a “terrible” situation.
“We don’t know when this [Cryptosporidium outbreak] started and we’ve got no idea when it will end.
“The reason we don’t know those two things is because the water has not been filtered.”
Council media spokesman Sam White said timeframes and costs for further investment in protozoa barriers would be included in the council’s long-term plan process.
Rose said he had a number of cancelled bookings to his 155-room lakefront facility this week.
It was never a good time to be issued a boil water notice, but with New Zealand and Australian school holidays beginning next week and a Chinese holiday at the end of the month, “now is a particularly bad time.
“The reputational damage [for Queenstown] ... would probably be quite large.”
A person with knowledge of the town’s water system, who did not wish to be named, said the council’s water testing was inadequate.
It was not doing enough testing at different points of the water distribution process or getting results quickly enough to be aware of risks.
Council infrastructure operations manager Simon Mason countered the claims, and said the supply was monitored regularly, in accordance with last year’s drinking water quality assurance rules.
“Unfortunately, Cryptosporidium is not specifically identified by any of the routine testing undertaken, and nor is it a contaminant that can be tested for in ‘real time’.”
The person claimed the council’s “single-source” Lake Wakatipu network was an issue because it meant water supplies could not be substituted and potentially contaminated water could not be isolated.
Mason said “as a result of investment currently under way”, water would soon be brought into the Frankton area from the new Shotover Country borefield and treatment plant.
— Staff reporter and Matt Porter
