Bid to fill in quarry site tested in court

Winstone has operated the scoria quarry on Mt Eden Rd since the 1920s. Photo / Steven McNicholl

A high-profile case over filling in one of the country's largest inner-city quarries was in the Environment Court this month.

Winstone Aggregates, a division of Fletcher Concrete & Infrastructure, and Envirowaste Services, were appellants in the case against Auckland Council, formerly Auckland Regional Council and Auckland City Council.

Winstone wants to rehabilitate the Three Kings Quarry site by filling it with about three million cubic metres of material which opponents claim is waste soil and inert waste. Residents near the quarry fear a plan to fill it with soil from building sites will lead to the land leaching toxic heavy metals into the environment.

A number of parties presented evidence at the hearing for and against the application. Bernie Chote said he had been general manager of Winstone for the past three years and had worked for the company for 15 years. He cited the quarry and Puketutu Island as having received environmental awards recognising their performance.

Winstone had operated the scoria quarry at Three Kings on Mt Eden Rd since the 1920s and quarrying had occurred in the general area for 150 years, he told the court. The 15.1ha site had adjacent land to the north, south and southwest which had been quarried.

This was a permitted activity at the exiting site and could continue, Chote said, because Winstone had authorisation via consent issued by the ARC to de-water below the quarry floor to sea level.

"Clearly if quarrying were to continue to that extent, not only would it be for some considerable time but the volume of fill material required to subsequently backfill the hole would be commensurately larger. Winstone has decided that on balance it is timely to plan to cease quarrying and rehabilitate the site," he told the court.

Works which would generate material Winstone proposed to use as fill included residential and commercial building, roading and port developments. Material would be taken from greenfield and brownfield sites, he said.

Chote said Envirowaste Services' appeal was based on a technical point that Winstone's original consent application was for cleanfill and the proposed fill did not meet this definition - a point he did not agree with, he said. Winstone's original February 2009 application remained the company's primary position, Chote said. But Winstone had elected to pursue a supplementary application for a consent to discharge contaminants on to or into the land associated with filling the quarry.

"Winstone's proposal to rehabilitate the Three Kings Quarry by filling has been well thought through and assessed over several years. This has culminated in a proposal that will have no more than minor adverse effects on the environment. There have been several professional and/or statutory bodies assess the potential effects on groundwater quality. They concur with Winstone's assessment that effects will be no more than minor," Chote said.

"The proposal will bring significant benefits to the wider region through providing an essential fill disposal resource.

"Filling is the foundation for the future for the future development of the site and the proposal will allow for long term sustainable development to occur once detailed end use is agreed through the future Auckland City processes."

John Stapleton, geo-environmental engineering manager from Babbage Consultants, gave evidence for Auckland Council that Winstone proposed to put contaminated fill material into the quarry.

His evidence cited discharge from crushed concrete, bricks and aggregate and he sought to have conditions placed on Winstone.

"While in my opinion there are a number of additional matters which the applicant needs to address in respect of the placement of contaminated or potentially contaminated fill material at the Three Kings quarry, these could be adequately addressed by way of the provision of further information and/or the imposition of further conditions of consent," Stapleton said.

Subject to that, he said he supported consent being granted.

Roger Parker, an environmental auditor of Golder Associates in Melbourne, gave evidence on behalf of Envirowaste that there was no internationally recognised definition of cleanfill compared to landfill.

"Given that there is a need to monitor groundwater at the Three Kings Quarry site and a need to place fill in accordance with the prescribed layering profile [to render the site suitable for future residential use] I conclude that the project [is] more akin to a landfill or a contaminated site rather than a cleanfill site."