Waikouaiti and Karitane residents have been told not to use tap water for drinking, cooking or preparing food after the discovery of high levels of lead in water supplies.
Tankers have been sent to the small townships so that people have access to clean drinking water.
The Dunedin City Council and Public Health South advice today comes as officials work to understand the cause behind significantly elevated lead levels detected at two drinking water sampling sites in the community and the raw water reservoir.
Council 3 Waters Group Manager Tom Dyer said the elevated levels were discovered during recent sampling, with the unusual results reported to the drinking water assessor and checked to ensure they were accurate.
He said the most recent high result was a test taken on December 8.
"The results were received by one of our staff members who was on leave on the 18th of December and we picked that up when the person returned from leave in the new year.
"So since that time we've continued testing, sought advice from Public Health South and that's just taken a bit of time to work through that to determine whether or not these are sustained results or a one-off. But we're determined that a precautionary approach is the way forward."
As a result, Southern DHB Medical Officer of Health Dr Susan Jack has recommended that, as a precaution, households not use tap water for drinking, cooking or preparing food while the source of contamination is investigated.
It was still safe to use the water for bathing, washing hands and clothes.
“We do need to rule out the risk that the elevated readings are the result of the contamination of the wider water supply,” Dr Jack said.
"We are asking people if they have got health concerns, they should make an appointment with their GP."
Further testing and risk assessment would be carried out by the council and the community will be updated on the results.
“We understand this news will be concerning. We are acting from a principle of caution, and wanting to give the community as much information as possible as we work to understand the situation,” Dr Jack said.
Mr Dyer said the water was sourced from the Waikouaiti River and supplied about 1500 people in the Waikouaiti and Karitane townships.
He stressed that boiling water did not remove lead, rather it can increase its concentration in water, so it was important for people to follow the advice and do not drink the water or use it for cooking or preparing food.
Mr Dyer said the source of the lead was unclear at this stage.
“The sampling was being undertaken as part of an asset management investigation, rather than drinking water standards monitoring.
"We were not expecting these unusual results, but they warrant a precautionary approach. Subsequent water samples have not shown elevated levels of lead.
“We’re ramping up our sampling, but at this stage it is unclear how long the water notice will remain in place. As soon as we know more, we will share this information with the community,” he said.
Dunedin mayor Aaron Hawkins said this afternoon a fleet of tankers had been sent north, and council staff would meet with local businesses and residents this evening and through tomorrow to help them get through "a disruptive and difficult time."
"These aren't ever the situations that you want to find yourselves in as a local authority, but we have our finest people on the job and they're trying to get on top of this and figure out what it is that we need to do to address this situation and get that supply operating again as soon as we can."
Where to find tankers
If you need water, bring containers to fill from water tankers at:
KARITANE
Community Hall - 1318 Coast Rd
Karitane Reserve playground area - 13 Bravas St
WAIKOUAITI
Golden Fleece Hotel - Kildare St entrance
