A Whangārei concrete company has been fined $52,500 for discharging contaminants from its manufacturing processes which may have then found their way into a drain which discharges to Whangārei Harbour.

AML Limited appeared for sentence before Judge JA Smith in the Whangārei District Court late last month after admitting a single charge in relation to the 2021 offending.

In sentencing notes Judge Smith said the offence could be summarised as the Port Rd concrete plant operating outside the terms of its certificate of compliance from 27 September 2021, through October 2021 and possibly as late as early-November 2021.

Judge Smith said the concrete batching site works recirculated process water and yard water through a ‘Bibko’ system.

"The Bibko seeks to clarify surplus/used water, reuse it for the concrete making process and thus reduce the overall water necessary for the operating of the site."

During Covid lockdown in 2021 the plant - deemed an essential industry - produced 438 cubic metres of high-stress concrete and 72 cu m of standard strength concrete.

"In this period the plant was producing 86 percent high-stress concrete and would have been unable to reuse water." (Typically high-strength concrete made up less than 40% of the plant’s production.)

"The reason that is important is that high-strength concrete requires clean water. It cannot use reused water."

In late 2021 production was still biased towards high-strength concrete, accounting for about half of production.

From about August the Bibko system started faulting. "That of course meant that less of the water could be reused and combined with the increase in high-strength concrete being produced, that meant there was surplus water on site."

The system was serviced in September but that didn’t eliminate the problem and "the company was in trouble because it was producing too much water".

"From September excess water was produced from the site and discharged into the nearby drains through the stormwater system."

In late September Northland Regional Council staff had visited the plant and found there was surplus water in the drain next to the site.

"This flowed around about 140 metres down the roadside to a culvert which was mostly blocked, and there was clear evidence, both photographic and technical, showing there was a high degree of what I will call cement sedimentation in that channel."

Water containing slurry then travelled under a road through another culvert, through adjoining land for several hundred metres and then into low-lying mangroves.

"There is no doubt that some of the material made its way as far as the Coastal Marine Area, but I accept the evidence of the experts that the effects on the harbour at large, and in particular that nearby Portland tidal flats, would have been minimal."

Judge Smith said overall the environmental impacts would have been minor and "mainly cumulative in nature".

"The harbour itself has been compromised by human activities for a considerable period from the refinery, the port, the cement works, boatbuilding, landfills, including rubbish dumps, and of course the formation of the development on which this heavy industrial zone is situated."

"Notwithstanding that, the SEAs (Significant Ecological Areas) have proved to be relatively enduring, and I accept that they should be regarded as of high value..."

Ultimately Judge Smith concluded "very firmly" that the case centred on "a failure of management to adapt to the changing circumstances".

There was nothing that demonstrated the company had wilfully sought to disobey its compliance certificate and the judge "accept(s) as a fact that the company was not aware of the discharge until they were approached by the council officers on 27 September 2021".

Judge Smith said plant staff would quite properly assume the company was operating properly and in accordance with its environmental obligations.

"The failure was a failure by management to recognise that the change to the production of the high-quality concrete and the Bibko faulting would fundamentally change the way to utilise the site."

Judge Smith noted the company had spent more than half a million dollars replacing the system with a new system but said the cost "cannot be visited as a mitigatory factor where it is simply complying with the obligation of the company in the first place".

The company was fined $52,500 plus court costs and solicitor’s fees for one day.

The judge directed that 90% of the fine be paid to the regional council.

© Scoop Media