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Tasman District Council engineers have noticed that part of the filtration system at the Motueka Wastewater plant is showing signs of degradation and while it is still functioning, it is not working at optimum levels.
Team Leader of Water Supply and Wastewater Becky Marsay says the area causing concern is the membranes that are in the final filtering stage of the wastewater treatment process.
She says these membranes remove any remaining bacteria and minute particles before the water is discharged from the processing plant.
“By the time the water gets to these membranes it is substantially treated.”
Becky Marsay says the engineers and Wastewater Team are at a loss to explain why this is happening and are urgently investigating a variety of options to deal with this problem, however it is likely the membranes will need to be replaced.
“Sourcing new membranes or having them manufactured, then getting them on to site and installed could take several months.”
To try and control the situation the Council has had to revert to a system used prior to 2016 and pump partially treated wastewater into the adjacent soakage area where it is then filtered through the ground.
Becky Marsay says while this area was retired several years ago, it is an option we have been forced to take to avoid uncontrolled overflows.
The Council is working closely with Iwi, Public Health, and the Ministry for Primary Industries to ensure any potential effects are monitored and minimised.
As a precaution, people should not take whitebait or shellfish or have contact with the water from the adjacent area until further notice.
The map shows the area to avoid.