The worm farm takes biosolids from wastewater treatment plants throughout the Bay of Plenty, mixes it with wood fibre from nearby mills and processes it into vermicast fertiliser.
The operation has been the subject of over 130 odour complaints to the regional council since September 2020, and there was a breach of an abatement notice in January 2024.
At a hearing before independent commissioner Gina Sweetman on December 10, employees of the neighbouring log yard (operated by Manulife Forest Management) described the “nauseating” smells wafting from the worm farm during the past decade.
On one occasion it was found that the biosolids had not been mixed with wood waste material before being laid out into windrows, as there had been insufficient wood fibre stockpiled.
At the submissions hearing, it was made clear the odours were strongest when the biosolids were being unloaded from delivery trucks, before they were covered with wood fibre.
McDowall said the plant’s expansion would make it easier to control any odours from the Tarawera Rd site.
A further bunker for unloading the biosolids further from the neighbouring log yard will be part of the expansion on to a neighbouring property.
“We’re really pleased with the outcome of the consent renewal process,” McDowall said.
“I think we got on really well with the submitters - positive and negative. It will be a positive, from an odour point of view, for our neighbours because we will be able to control it better.”
Conditions of the new consent include a limit of 32,000 tonnes of raw materials (not including the wood fibre) to be brought on to the property over any 12-month period.
It requires at least three days’ supply of inert substrate (wood fibre) to be stockpiled at all times and four days' supply of weed mat and lime to be stockpiled - to be placed over windrows in the event they become odorous.
There is to be no stockpiling of biosolids from wastewater treatment plants. All raw material being delivered to the site is to be immediately covered by a layer of wood fibre to reduce odour.
A complaints register is also to be maintained on-site to record any reports of odours, what caused them and what was done to mitigate the odour. This register must be made available to Kawerau District Council on request.
Representatives of Ngāti Tuwharetoa (BOP) Settlement Group must also be invited to form a tangata whenua liaison group with the consent holder to provide cultural perspectives and mātauranga on all matters about the operation of the site.
McDowall said the company was happy to comply with all the conditions set out in the consent.
He said he had not had any complaints about the odour in recent weeks and the regional council had not made them aware of any complaints made through its Pollution Hotline.
People who made submissions on the consent application have until February 7 to appeal the decision.
- LDR is local body journalism co-funded by RNZ and NZ On Air.
