"The structure could collapse": warning from experts as QLDC sewage inaction continues
Sewage is still being discharged into the Kawarau River
A Crux investigation. Peter Newport.
There’s been no new word from either the QLDC or ORC this week on the continued failure of the Shotover waste disposal site in spite of millions of litres of effluent flowing into the Kawarau River.
Both central Government and the Environmental Protection Agency have said they can’t intervene due to the fact that the ORC has already started legal action via two abatement notices and six infringement notices. Both however are watching the situation closely.
One expert we spoke to this week has told us that the earth bank surrounding the dispersal field could collapse at any stage, noting that the pipe dumping effluent into the Kawarau River is the only factor preventing such a collapse.
It’s not a theoretical point.
Part of the bank collapsed on two occasions earlier this year while ORC investigators were on site. They photographed the damage. Also note how much lower the new, illegal artificial bank was at that stage - relative to the fence - compared to the main image taken this week at the top of this article.
Here’s how the ORC documented the collapse earlier this year in one of their many documents that detail the effluent discharge.
“The ORC Enforcement Officer noted that the Disposal Field now looked like an oxidation pond which was approximately 1 metre deep. While observing the Disposal Field the internal earth bunds/walls made of earth began crumbling and collapsing.”
“The outer earth bund (which was keeping wastewater within the Disposal Field) suddenly and completely failed on the eastern side of the Disposal Field. A substantial flow of wastewater from the Disposal Field ‘pond’ flowed between the bunded cells of the Disposal Field and discharging overland on the eastern side of the Disposal Field. This wastewater ponded between the boundary of the Disposal Field and the Twin Rivers Trail which runs alongside the Disposal Field.”
And on another occasion:
“On the 3rd of March 2024, the ORC received a complaint that, “there was burst pipe coming from the wastewater treatment plant in the Lower Shotover”.
“In response to the complaint, an ORC Enforcement Officer carried out an inspection of the WWTP. The officer observed that a bund (which was keeping wastewater within the Disposal Field) on the eastern side of the Disposal Field had breached. Wastewater from the Disposal Field was discharging overland through the eastern Disposal Field boundary fence into the Shotover Delta where it was ponding.”
The experts we spoke to this week added to the developing knowledge we have of what has happened at the plant since it was commissioned.
Early evidence of soakage and flow from the dispersal field being inadequate and not to spec.
Contractors experiment with changing the chemical balance and filling then emptying different water cells within the field
Within 18 months the problems get worse and contractors start digging new channels and ponds including an “emergency” channel on recreational reserve land towards the Kawarau River.
The emergency channel is then decommissioned on instructions from the ORC.
QLDC managers have been aware all of the early period that effluent was reaching both the Kawarau and Shotover rivers.
Contractors get blamed for the problem with some team members are removed as “scapegoats” and a new team put in place.
These team members who get removed include one man in particular who had become an expert at trying to contain a delicate balance within the failing field.
Things then continued to get worse and contractors discover the actual cause of the problem is the solid human waste making its way into the disposal field.
This is a major design fault and there’s no physical filtration or pumping to return solid waste back to the first treatment ponds from the UV treatment building.
The solid waste proves virtually impossible to control and new algae starts to form causing further permanent blockage.
The gravel bed starts to overflow and become inundated. More effluent reaches the rivers.
A permanent overflow pond is built to discharge wastewater to the Kawarau River
QLDC contractors build a massive earth bank around the field - without resource consent. There’s no evidence QLDC even told ORC what they were doing.
Effluent flowing south through the recreation reserve gets underneath a large raised rock bank (part of the Twin Rivers Trail) and then flows freely into the Kawarau.
The field bank needs to be built higher and higher as the water level rises. Parts of the bank collapse (see photos above)
More material is trucked in to further increase the height of the bank.
The bank is exposed to the risk of a total collapse that would spill unprecedented amounts of effluent into local rivers.
Extra material is trucked in to make the emergency field bank even higher.
Crux video shot this week of the overflow pond discharging effluent via a permanent pipe installed under the boundary fence.
Crux video of effluent flowing into the Kawarau River this week.
If you want a truly frightening perspective on how poorly this situation is being handled please read this this article written by Crux in June, 2024.
You can also read the ORC abatement documents here.
