Whanganui District Council are confident the district's water testing procedures are adequate after a lead contamination scare in Otago. Photo / Bevan Conley
Whanganui District Council are confident the district's water testing procedures are adequate after a lead contamination scare in Otago. Photo / Bevan Conley
Whanganui District Council is confident in its processes to ensure Whanganui's drinking water is safe after some Otago residents were found to have been unknowingly drinking lead-contaminated water for weeks.
Residents in Karitane and Waikouaiti were told last week not to drink tap water after elevated levels of lead werefound in the areas' water reservoirs.
It was subsequently revealed that the Dunedin District Council was first alerted to the elevated lead levels in August, but failed to inform local residents after the council concluded the result was simply a one-off spike.
However, a further test conducted on December 8 showed lead levels of 0.39 milligrams per litre, equivalent to almost 40 times safe levels.
According to Whanganui District Council's senior engineering officer Dave Rudolph, Whanganui's drinking supply is continuously tested to ensure that all levels are safe, with safeguards to ensure a scenario such as that seen in Otago did not occur here.
"Samples are taken monthly from various sample points at the source and within the reticulation by the WDC compliance team. All samples are sent to accredited laboratory Central Environmental Laboratory in Palmerston North," Rudolph told the Chronicle in a statement.
"All drinking water supplied by Whanganui District Council is chlorinated. Chlorine, turbidity [colour], PH and temperature are continuously monitored by online equipment at the main reservoir."
Whanganui District Council's Senior Engineering Officer Dave Rudolph said that the council often samples the water more than what is required. Photo / File
Asked about the frequency of testing, Rudolph said that the council often over-samples to ensure more frequent and accurate results, in an attempt to catch any spikes before they become serious risks.
"Whanganui bores have secure bore status – monitoring requirements for (source water) secure bores are one sample from each site every quarter, but we over-sample and complete one sample every month."
"For the network or reticulation monitoring, requirements are for samples to be taken at a frequency of every five days. As mentioned, all samples are collected and sent to the accredited lab for testing of total coliforms and E. coli."
Rudolph said while Whanganui had not had any issues with its water supply in recent years, there were stringent processes in place to ensure that the public is informed if issues were to arise.
"There are procedures in place to indicate a potential issue within the water supply before it gets to a positive transgression. All transgressions or non-compliant samples are notified or alerted to appropriate persons as soon as a sample is tested," Rudolph explained.
"As mentioned, we would need to complete certain actions and procedures before the public was notified. Notifiable actions would be completed through our communications team. All positive transgressions are also automatically reported to the Ministry of Health's drinking water assessor."
