Council backs away from farmland sludge plan

Central Otago District Council is set to drop, for now, a plan to truck treated human sludge from Cromwell to farmland near Lauder. Staff added a late item to Tuesday's agenda recommending the stored sludge go to the Winton landfill in Southland instead, because the Lauder site might only be able to take half of Cromwell's sludge.

The change removes the main argument for the original plan. Councillors were first told Lauder would save at least $600,000 compared with an estimated $1.6 million to cart the material to Winton. The updated estimate for Winton transport plus de-sludging the ponds is now more than $3 million, including contingencies. Councillors decide on Wednesday.

The plan had angered Federated Farmers and locals, who say the site is unsuitable and that they had no say in how the consent was granted.

The record

The sludge problem is real and pressing. Cromwell's wastewater ponds were de-sludged a decade ago into geobags, which let the sludge dry and cut transport costs. About 20,000 cubic metres has built up in the ponds again, and removing it was estimated at $2.8 million to $3.2 million.

Three Waters group manager Julie Muir told councillors the work was needed "as a matter of urgency". If a consent condition on nitrogen loading is triggered, she said, the nitrogen and ammonia limits drop significantly and would require more costly treatment. A Beca review earlier this year found the Cromwell plant needed immediate and ongoing upgrades to avoid triggering those limits because of growth.

The Lauder option relied on an existing non-notified consent. The Otago Regional Council granted it in January to the Queenstown Lakes District Council, and it already allows Wānaka's sludge to be spread at the property. The council's own budget for sludge management is $1.15 million a year, which historically included $530,000 to move Alexandra's sludge to Winton.

The first staff report said testing of the Alexandra sludge and the Cromwell geobags met the consent requirements for Lauder. It called Lauder the most cost-effective and legally compliant option, despite community unhappiness.

Open questions

Several tensions remain, even if Cromwell's sludge no longer goes to Lauder. The updated report says Alexandra's sludge might still go there, because it fits within the consent conditions. So the site is not fully off the table.

The report also says that if personal hygiene products turn up in the geobags, it would affect the ability to spread sludge at Lauder. How likely that is, and why it surfaced only after the first recommendation, is a fair question for councillors to put to staff.

The consent itself is the bigger issue. Federated Farmers Otago president Anna Gillespie says local farmers believe a notified consent would have let them stop it. The regional council says it was non-notified based on an assessment of the information supplied with the application. Who decides what counts as enough information to skip public notification, and whether that threshold was met here, is what locals want answered.

Central Otago Environmental Society co-chair Matthew Sole says the community is "hamstrung with a lack of decent scientific information" on whether spreading can be done safely. He asks how biohazards, chemicals, heavy metals and microplastics would be managed. Mayor Tamah Alley says she first heard of the consent from a member of the public.

The other side

The regional council says the consent was processed in accordance with the Resource Management Act and is subject to regular compliance audits. Chief executive Richard Saunders says the council takes community concerns seriously, has spoken with residents, and will keep engaging. He did not rule out a review of the consent, but said it is "too early to say what if any changes may be sought".

Queenstown Lakes Mayor John Glover says his council did not drive or issue the separate consent between SJ Allen and the regional council. He says it could only have been achieved with the willing consent of the rural landowner. He adds that his council uses the Winton landfill for the majority of its sludge and is pursuing long-term solutions, including talks with central government on a Regional Deal.

Mayor Alley says land discharge has a time and a place, and that councils must plan for waste from growth in ways that are sustainable, financially responsible and environmentally responsible. She says the council wants to deal with its own waste rather than ship it elsewhere. Staff's case is also practical: delays risk contract variations and higher costs, and the ponds need clearing soon.

What happens next

Councillors decide on Wednesday. The choice is between the new recommendation, sending the stored sludge to Winton at a cost above $3 million, and the original Lauder plan. Three tenders have been received for removing the geobags and de-sludging the Cromwell ponds.

Watch for whether Alexandra's sludge is still directed to Lauder, and for any move by the regional council to review the consent. Saunders says community information is helping to shape its response. Federated Farmers wants the original consent reconsidered.

Ratepayers should also watch how the extra cost is funded. The saving that justified the Lauder plan has gone, while the pressure on Cromwell's ponds has not.