Circumventing consenting

You wouldn’t think it could happen these days: a major community upgrade that didn’t have to fight its way through the Environment Court.   HUGH DE LACY reports.

Ashburton.jpgIt’s one of the fastest-growing communities in the country, but not a single dissenting voice was raised in court against the Ashburton District Council’s biggest-ever infrastructural project, the $16 million upgrading of its sewerage system.

Riding on the back of a dairy-driven farming boom, Ashburton, over the past decade, has blossomed from a sleepy provincial town to the vibrant trading centre of mid-Canterbury.

Global dairying co-operative Fonterra has its giant Clandeboye factory within easy tanker-reach of the district’s burgeoning dairy industry, while the country’s largest beef feedlot at its back door underwrites strong demand for a range of locally-produced arable crops – these days including livestock feed from the council’s own farm.

Southern Alps tourism is another expanding industry that, together with agriculture, has driven Ashburton’s population up towards the 17,000 mark, with the expectation it will be double that within 25 years.

As early as 1993 the council began investigating options for the upgrading of a sewerage system that collected wastewater from 8000 domestic, industrial and commercial premises, conveyed it along 97 kilometres of pipeline to two oxidation ponds and its eventual discharge directly into the Ashburton River. Even by then the population was outgrowing the reticulation system, to the degree that peak flow-rates had become unmanageable and it could no longer meet environmental standards.

Further investigations were carried out in 1996, and the following year the council formed a working group to drive the upgrading project through to completion.

The pressure really went on the council in 2002, however, when the existing resource consents expired, allowing operations to continue only by virtue of existing-use rights. So it was that in 2003 the council took the bull by the horns and applied for resource consents for a scheme that envisaged irrigating the council’s 282 hectare Ocean Farm south of the town with the treated waste.

The notified scheme involved building a new 18,000 cubic metre aeration pond with 10 aerators on the Wilkins Road site of the two existing oxidising ponds, along with a new pumping station and control room, a step-screen to remove gross solids and a rotomat for the disposal of septic tank waste.

From there a transfer pipeline would be constructed comprising 5.75 kilometres of 675mm diameter pipe, 4.1 kilometres of 700mm, and 1.1 kilometres of 900mm pipe, accessible through 42 manholes and with four siphons at key road-crossings.

Down at Ocean Farm, near Ashton Beach, an 11,000 cubic metre storage pond was to be built along with a further pumping station and control room to feed 11 kilometres of pressurised control pipeline, 60 kilometres of irrigation laterals and 1400 pop-up sprinklers.

But before the effluent was sprayed out on the paddocks, it was to pass through a nine hectare shallow wetlands area converted as such from a paddock and planted with 287,000 wetland plants. There the natural sunlight and ultra-violet rays would break down the remaining nitrates and chemicals, “polishing” the liquid so that it was virtually pure water that was sprayed out through the irrigation system.

Grass was to be grown on the irrigated area for a cut-and-carry operation – hay, silage and the like – to service the district’s ever-expanding appetite for feed for livestock. Resource consent applications had to be lodged and notified for the continued operation of the existing oxidation ponds, for land designation, and for construction and operation of the upgraded system.

With a scheme covering such a large geographic area and affecting the lives and property values of so many people – not to mention the straitened pockets of the ratepayers – it was not surprising that the applications initially attracted 30 objections. But with an Environment Court hearing seeming inevitable, and involving the council no less than the objectors in a drawn-out and expensive legal process, the council swung into action with an intensified consultation programme based on face-to-face discussions with every one of the objectors.

“Their concerns were mostly environmental,” council operations manager Rob Rouse told Contractor. “Some were worried about aerosol drift from the irrigation system, and some about the odour. We did a high-level one-on-one consultation to see if we could clarify the situation, provide additional information or mitigate their concerns.

“In every case we were able to achieve that. We provided them with technical information and assurances, and we also made some minor adjustments to on-site work, which wasn’t onerous from our point of view but delivered a better outcome,” he says.

As a result, every one of the objections was withdrawn, and the consents were issued without the need for Environment Court endorsement in June of 2004. It’s an achievement believed to be unique in New Zealand for a project of such a size and complexity.

The final design work was completed in 2006, construction begun in January 2007, and in April of this year the district mayor, Bede O’Malley, threw the switch bringing the whole scheme into operation.

The project employed three main contractors: the Christchurch branch of Downer EDI Works for the treatment plant, Meyer Construction of Clyde, Otago, for the transfer pipeline, and local company Rooneys Earthmoving for the groundworks. Project management was by Andrew Whaley of the Christchurch branch of consultants URS, who told Contractor the whole operation went through without a hitch.

“We were expecting big groundwater problems with the pipeline but they didn’t eventuate, probably because of the

methodologies used by the contractor, Meyer, who were pro-active with the cleaning out of side-drains which assisted with localised de-watering,” Whaley says. “The other thing we had an issue with was the lining of the wetlands so they didn’t leak, and again there was a pro-active testing regime put in place by the council, URS and Works that came up with a solution that kept the project on track.”

The three contractors worked in parallel, with staffing levels peaking at around 30. Some 70,000 cubic metres of spoil had to be moved.

Ocean Farm, which was once the home of a former Ashburton mayor, Murray Anderson, generates an income for the council, and will also be the site of a planned Greek village that will feature in a forthcoming movie about North Canterbury’s double Victoria Cross winner, Charles Upham. This was a project the council was happy to lend a hand to, even though Upham’s home district of Hurunui declined the invitation to participate.

The whole sewerage upgrade project has been designed to cater to the continued rapid growth of Ashburton and mid-Canterbury, having as it does the capacity to be extended as demand dictates. And if ratepayers in the future like to think back on it, they can congratulate themselves on having the collective foresight and unity to have put it in place without having to jump through the avoidable hoops of the Resource Management Act and the Environment Court. 


Contractor Vol.32  No.6  July 2008
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