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Bio-solid composter plant to close

Fuseworks Media
Fuseworks Media

The bio-solid composter unit that's been trailing production of grade Aa compost will be permanently closed from Monday 2 October.

"The reality is the composter is costing ratepayers a considerable amount to run and it's just not financially viable," says Bruce Hinson, our Council's Infrastructure Delivery Group Manager. "It was purchased as a second-hand machine, so the plant is starting to age, we're spending tens of thousands in maintenance and depreciation and the costs are just outweighing the benefits."

Our Council has taken careful consideration to reach the decision to close the plant. Including:

- The volumes of bio-solids able to be accepted are relatively low (40 tonnes per month) at peak capacity.

- The asset is starting to age so in addition to repairs undertaken last year, there needs to be an additional $40K spent on maintenance and eventual asset renewal would be required.

- Operating costs are in excess of $220K per annum.

- When the composter was first set-up as a trial back in 2007, there were assumptions that fuel costs and landfill costs would rise, which meant composting bio-solids would be financially beneficial. In reality, transport and fuel costs haven't increased in the past 10 years as expected.

- Over the past three years Council staff have investigated potential commercial markets and modelled financial results and future viability, all of which has proven it is not financially viable.

The composter started out as a trial back in 2007 with Council publicly signalling it would keep reviewing the viability of the composter to see whether it was cost effective.

This included an independent report commissioned in 2014, which found there was no significant financial benefit to retain the composting operation. You can read the report here.

Following that report, Council asked staff to come back with more detailed figures on compost volumes, along with a decommissioning plan for the composter and possible options for re-use of the Whitianga site.

"We didn't want to make a snap decision so staff went away to conduct a 12-month trial to determine viabillity," says Mr Hinson. "That got extended to nearly two years and after looking at all the details again, nothing significant has changed. Getting enough green waste into the composter isn't the problem - even with a more than adequate supply of greenwaste, the composter plant cannot process a high enough volume of bio-solids to be economic based on the costs required to operate".

The closure of the plant on 2 October gives the community and stakeholders time to be made aware of the decision. We have also been communicating with stakeholders individually. Once the operation has ceased, work will commence on decommissioning of the composting plant, with a number of options available around this.

"We are not ruling out that we will be able to do some form of composting in the future, which we hope will involve regional support, or cost-sharing benefits with other councils," says Mr Hinson.

Disposal of green waste

We had been advertising that green waste could be dropped off for free at the composter site while the trial was underway. This will no longer be available. Green waste can still be dropped off at all of our Refuse Transfer Stations. You can find out the location and hours here

Bio-solid composter history

- 2007 - Council started investigating how we could sustainably manage and investigate environmental benefits using biosolids taken from our Wastewater Treatment Plants on the Eastern Seaboard.

- 2009 - An 18-month temporary trial was set up in Tairua to see if it could produce Grade Aa compost that we could use on our parks and reserves. This was successful.

- 2012 - The plant was moved to a permanent site in Whitianga and part of the resource consent was that Grade Aa compost had to be made, which for the first eight months could be used only on our parks and reserves. (This was also successful).

- 2014 - As part of our 2015-2025 Long Term Planning our Council reviewed the viability of the composter, and commissioned an independent report to assess the cost benefits. The report was presented to Council's Infrastructure Committee in November 2014 and suggested there was no significant financial benefit to retain the composting operation and it was more cost effective to dispose of bio-solids to landfill rather than compost. Council's Infrastructure Committee resolved at its meeting in October 2014 that staff should come back to the Committee in 2015 with detailed figures on compost volumes, along with a decommissioning plan for the composter and possible options for re-use of the Whitianga site. It also recommended Council's Audit Committee consider any future financial risk to ratepayers.

2015 - A report to the Infrastructure Committee in June showed that there was a potential commercial market identified and that the 2014 assessment incorporated a number of scenarios, which modelled financial results that may not have fully reflected the financial viability of the activity. You can read the report here (item 2.2). Council agreed that our contractors Veolia take over management of the composter with the aim of producing financially viable Grade Aa compost for the public to purchase. Meanwhile investigations would begin to see if any commercial business would invest and to reassess in 12 months' time, the commercial viability of the composter. This trial was twice extended to an eventual 24 month period.

- 2017 - Report goes to Infrastructure Committee with staff recommendation to cease operations at the composter as the operational costs outweigh savings. Council endorse Infrastructure Committee's recommendation.

For the complete history of the composter trial and all the assessment reports go to

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