Queenstown, a popular tourist destination on the South Island of New Zealand, has been placed under a boil notice following several confirmed cases of cryptosporidium, an illness caused by the protozoan. Queenstown Mayor Glyn Lewers says the town’s reputation has taken a hit with the recent water crisis.
The city is world-renowned for its natural beauty and for a plethora of tourism activities ranging from adrenaline pursuits such as bungy jumping, jet boating, white water rafting, etc., to slower-paced activities like hiking and biking trails, wineries, guided tours for those who want to relax and unwind.
NZ Herald reports that the town’s urban population, 29,000, has confirmed cases of gastro disease that rose from two to 17 on 20 September 2023. The article notes that the city could expect a boil notice for months.
Stuff reports that a boil notice was placed on 18 September following a cryptosporidium outbreak in the town. By 5 October, the boil notice was lifted in parts of the city – Kelvin Heights, Frankton, where the new sprawling business area is, Hanley’s Farm, Quail Rise, and Tucker Beach Rd.
However, the boil notice remains in Queenstown Town Center, Queenstown Hill, Frankton Road, and suburbs on the hill above Frankton Road out to and including Goldridge Way and Goldrush Way, Fernhill, and Sunshine Bay, which means that they have to abide by the current restrictions, which is expected to last until December or until the council installs the UV disinfection equipment.
The cryptosporidium outbreak revealed that Queenstown’s main water supply had no filter to protect it from the protozoan parasite.
Queenstown Mayor Glyn Lewers has announced that the council has purchased the disinfection equipment, which is an effective protozoa barrier and a long-term solution to stop further cryptosporidium outbreaks in the future.
As of 2 October, the number of confirmed cryptosporidium cases further rose to 56, with 12 probable cases and eight under investigation, according to data from Public Health South.
Source of the outbreak
The presence of cryptosporidium in water is quite tricky to detect. But when the outbreak became apparent, authorities considered the town’s water supply the most likely source.
However, Stuff reports that when samples were taken from the town’s water supply, it gave negative results, which indicates the council’s main water supply is less likely to be the source of the outbreak. The article notes no cases in aged care or hospitals, which directed the council to look outside the distributed water network.
The council’s main water supply has not been ruled out as a source, and the council’s key focus was to fulfill the compliance order issued by the country’s drinking water regulator, Taumata Arowai, the mayor said.
The Two Mile water treatment plant, which provides reticulated water supply to the main town center and much of the surrounding areas still under the boil notice, lacks the protozoa barrier. This means the water treatment plant is non-compliant, and Taumata Arowai (TA) is working with the council to remove the issue, NZ Herald reports. The boil water notice must remain until either treatment for protozoa is in place and operating.
The Two Mile water treatment and the Kelvin Heights treatment plant, which serves the areas where boil notices have been lifted, took water from Lake Wakatipu. The council has also created an updated drinking water safety plan to isolate the water supplies and distribution from the Kelvin Heights treatment plan, where the boil notices have been lifted.
In the meantime, the council asks everyone in the district to maintain good hand hygiene to reduce the risk of secondary infection.
Water New Zealand points to the poorly installed and maintained onsite wastewater management systems or septic tanks as the likely source of the outbreak because of the negative results and the uncertainty that the reticulated drinking water is the source of the fecal matter that has caused the illness in town.
In Queenstown, about 10% of its local population relies on septic tanks; nationwide, around 18% or 1 in 5 New Zealanders depend on onsite wastewater management systems.
Water New Zealand Chief Executive Gillian Blythe says these onsite treatment systems pose a real risk to drinking water and the wider environment, mainly if they are old and poorly maintained.
“For instance, it would only take one substandard onsite wastewater system at a school, camping ground, marae, or single rural dwelling to put a neighboring community water supply scheme at serious risk.”
Blythe adds that Queenstown’s cryptosporidiosis outbreak has again highlighted the need for better and more consistent regulation of onsite wastewater management systems across the country (Queenstown outbreak, 2023).
Sources:
Porter, M. (2023, September 21). Queenstown Cryptosporidium outbreak: Affected water lacks parasite filter. NZ Herald. Retrieved from https://www.nzherald.co.nz/nz/queenstown-cryptosporidium-outbreak-affected-water-lacks-parasite-filter/JCCI4VJEQBEOZM6I4TKFDWQ73I/
Jamieson, D. (2023, September 25). Hunt for Queenstown’s cryptosporidium source shifts to businesses. Stuff. Retrieved from https://www.stuff.co.nz/national/health/133002653/hunt-for-queenstowns-cryptosporidium-source-shifts-to-businesses
Price, M. (2023, 6 October). Boil water notice partly lifted. Otago Daily Times. Retrieved from https://www.odt.co.nz/
Arora, S. (2023, October 5). Boil water notice lifted for some parts of Queenstown after cryptosporidium outbreak. Stuff. Retrieved from https://www.stuff.co.nz/national/300983020/boil-water-notice-lifted-for-some-parts-of-queenstown-after-cryptosporidium-outbreak
Queenstown outbreak shows need for better regulation of onsite wastewater systems. (2023). Water New Zealand. Retrieved from https://www.waternz.org.nz/Story?Action=View&Story_id=2105
Leave a Reply