Research prompts TasWater to back its Pioneer water solution

An independent review of research into the source of lead in the water supply of Pioneer has identified some deficiencies in the research and in TasWater’s opinion supports the decision to replace the reticulated network with individual tanks for its 42 customers.

Earlier this year a Macquarie University research project suggested the source of lead in Pioneer’s water was in the network of pipes throughout the town.

For several years TasWater has been aware of sporadic elevated lead levels in Pioneer’s water supply and has complied with a Department of Health and Human Services Do Not Consume notice.

TasWater has been supplying potable drinking water from a community tank located in the township while a water tank program is implemented.

“TasWater’s decision to have the Macquarie University research reviewed was not aimed at challenging the presence of lead but instead testing elements of the research methodology and subsequent suggestions that TasWater’s response to the presence of lead was less than adequate,” TasWater’s CEO, Michael Brewster said.

The review, carried out by Water Research Australia (WRA), questions important areas of the research carried out by Macquarie University:

 Water samples for the study were taken from storages no longer supplying the town ship of Pioneer

 The sampling protocol was poorly described with insufficient repeat tests from the sample locations to provide confidence in the integrity of the sampling regime

 In the opinion of the WRA review panel, some of the water tests are what would be described as first flush water and may not be accurately representative of the supply.

“We accept some findings of the Macquarie University study. We are aware of the presence of very low levels of lead in the water source supplying Pioneer and we acknowledge lead may leach from pipes and fittings.”

Water Research Australia believes the lack of sufficient sampling made isotopic fingerprinting – which enables lead to be traced back to its source – unreliable in identifying the source of the lead contamination.

The Macquarie University research also claimed leaching of lead from PVC pipes in the Pioneer reticulation network. While past studies of PVC pipe say this is possible, in well flushed reticulation networks it does not lead to lead reaching dangerous levels in the water but lead may build up in stagnant zones of the network.

In conclusion the review finds

 Pioneer’s water supply shows intermittent elevated lead levels

 The lead could be from a variety of sources

 Leaching from pipes in the distribution system is a potential source but couldn’t be confirmed from the data

 Leaching from household plumbing likewise is possible

 Much of the data in the Macquarie University study is based on potentially unreliable first flush sampling after extended periods of stagnation

 A small sample base and lack of follow-up testing compromised the reliability of the findings.

“The water tank program which TasWater is implementing gives Pioneer’s residents the most reliable, safe and feasible solution. Importantly, it addresses concerns over bacterial contamination of the raw water supply to Pioneer which has frequently demonstrated levels of e.coli above Australian Drinking Water Guidelines.

TasWater urges all property owners who have not signed up to the scheme to do so at the earliest opportunity.
TasWater