Council probes stream health

Rangitikei District Council is investigating the effect leachate from the Bonny Glen landfill has on the Marton wastewater system. PHOTO/ STUART MUNRO

Leachate from the Bonny Glen landfill is probably harming the health of the Tutaenui Stream.

Rangitikei District Council is investigating the effect leachate from the Bonny Glen landfill is having on the Marton waste water system. As it stands, it appears the waste water system cannot handle the volume of leachate being put into it.

Since 2008 leachate has been trucked from the dump and put into the Marton waste water treatment system.

In the year to June, 13,451m3 in waste discharged. It equates to about 4.2 per cent of the average daily flow of the waste water in the system. A report to the Rangitikei District Council's asset and infrastructure committee by former asset manager Phil O'Connor said that was a significant amount. RDC has a consent with Horizons Regional Council to discharge into the Tutaenui Stream. But that is regularly exceeding consented levels of biological oxygen demand, ammonia and suspended solids.

On top of that, testing of the leachate showed "very high readings" of all three. "They are reliant on the dilution of the Marton domestic wastewater stream, to bring these down to an acceptable level for treatment at the Marton WWTP," the report said. But the daily flow to the Marton WWTP is less than first thought and what the agreement between the council and the dump was based on.

Chairman of the council committee Dean McManaway said it was a concern but an issue the council was taking seriously. A detailed report by Opus International was due in December, he said. "The idea of the report is to get on and try to find a solution," he said.

"It's not right the plant is not meeting it's consent obligations ... (but) there are ways to solve this. We've got things to work on and we'll get it right." The two parties have discussed ideas around partial treatment of leachate at the source, a contribution to the wastewater operations or payment through trade waste charges.

The Opus report will also consider appropriate charges for the treatment of the leachate. Meanwhile, the Bonny Glen landfill is in the process of getting consent to significantly expand its operation.