The latest water samples from the Otago towns of Waikouaiti and Karitāne where lead levels spiked in December, have revealed that levels are now "extremely low" or "undetectable"
The situation has Dunedin City Council officials puzzled after high levels of lead have been found at some sites in the area but not others.
It took two months for Dunedin Mayor Aaron Hawkins to find out and a do not drink order to be issued but as anger grows, he’s defending his response.
“Me knowing earlier wouldn’t have made a material difference in terms of how we handled it in terms of a public health perspective because we were following the guidance of the public health authorities."
“Once we get into a position where we are second guessing public health advice based on our own reactions, then I think that’s a dangerous path for us to go down,” he told 1 NEWS.
The community is looking for answers at a public meeting tonight.
Elevated lead levels in Waikouaiti were reported as early as August last year after testing at the Waikouaiti Golf Club. But, this was determined as being a “one-off spike” after consultation and subsequent testing, RNZ reported.
Lead levels for the next 14 weeks were below acceptable limits. But, in October, there was another high result in the same location, and again in December. Testing at Karitāne Bowls Club also returned a high result.
One sample on December 8 found 0.39 micrograms of lead per litre, almost 40 times the acceptable level of 0.01 micrograms a litre. But, another sample taken from Waikouaiti’s main street returned a result well below acceptable limits on that same day.
DCC Chief Executive Sandy Graham says results of samples taken at six sites (three at the treatment plant and three elsewhere on the network) on Monday came back late yesterday, and showed low or non-detectable levels of lead.
Three results taken from Waikouaiti TAB on main street (non-detectable), the Golf club (0.0044mg/L) and Karitane bowls club (0.0008mg/L) were all well below the acceptable limit of 0.01mg/L, while three results from the treatment plant were below detectable levels.
Graham says the latest samples add to the 90 taken in recent months, which together have returned six results above acceptable limits and many more below.
“These intermittent elevated levels are still clearly a cause for concern, especially for the residents of Waikouaiti and Karitane, and we are pulling out all the stops to get to the bottom of this issue.
“But these results do underscore the point that we are dealing with fluctuating, occasional spikes – not prolonged exposure to high levels of lead in the water.”
Graham also says she completely agrees with the Prime Minister’s comment today that the situation facing residents in both communities is unacceptable.
She says that is exactly why the DCC issued the ‘no drink’ notice earlier this week and why DCC staff are working hard to find the source of the contamination and fix the problem.
This includes moving to a daily testing regime to more accurately pinpoint any future spikes should they occur.
In the meantime, work has already begun to excavate and test the condition of some sections of old cast iron water pipes in Waikouaiti.
While the source of the contamination has not yet been confirmed, lead joins in older pipes, environmental contamination in the wider catchment, or even sampling errors, are all potential causes of the spikes.
The DCC plans to replace the piping sections which include lead joins in the near future to remove that potential source of contamination from the network.
Staff are also continuing to ensure residents have access to water tankers providing clean, safe drinking water from the city. More than 2500 containers have also been supplied for people to use, and have been door-knocking in the communities to ensure everyone is aware of what is happening.
Staff have been on hand to answer any questions at the tankers, and will be attending tonight’s Public Health South public meeting in Waikouaiti, alongside Mayor of Dunedin Aaron Hawkins and Councillor Jim O’Malley, as chairman of the DCC’s Infrastructure Services Committee.
So far, extra testing has not produced any evidence of sustained elevated levels, beyond the spikes already reported, but efforts to trace the source and resolve the issue will continue.
Local gold mining company, OceanaGold Macraes Operation, issued a statement this afternoon, reassuring the East Otago community that its operation was not reponsible for the water contamination.
"The rock at Macraes is characterised by orogenic mineralisation. This does not contain lead within the rock in the way that some regions do," the statement said.
"We test water in and around the Macraes site each moth for multiple trace elements, including lead. These water samples are sent to an accredited independent laboratory for testing.
"We provide the Otago Regional Council with this data as part of our consent conditions."
The company said it had never returned a result above 0.002g/m3.