Boskalis defends track record at Chatham Rock hearings

Royal Boskalis, one of the world's biggest dredging companies, defended its track record in making the case for a proposed phosphate mining project on the Chatham Rise, and is confident the measures it would take to protect the environment would aid recolonisation of the area by marine life.

The Rotterdam, Netherlands-based company is the proposed partner with Chatham Rock Phosphate [NZAX: CRP] to mine phosphate nodules from the seabed on the Chatham Rise, some 450 kilometres offshore to the east of Christchurch, providing the engineering expertise to undertake the project. While the two companies haven't formally entered into a contract, Boskalis is an investor in and an integral part of Chatham Rock's application to mine the area, and three of the Dutch firm's representatives gave evidence to the five-member decision-making committee hearing submissions on the project in Wellington yesterday.

"It is important to note both CRP and Boskalis have committed to work together on this project," development dredging manager Sander Steenbrink told the committee. "We have come a long way and it would very difficult for another company to come and step into the project and do that work."

If another company was successful in winning the bid to undertake the project, it would have to negotiate the use of Boskalis's intellectual property, which was part of the Chatham Rock application.

Steenbrink said Boskalis has a strong track record around the world in managing these types of projects, and that he considered measures to mitigate the impact of mining on the environment by leaving areas to aid recolonisation of the marine ecosystem met the firm's corporate social responsibility goal of 'building with nature'.

He didn't think there were any technical concerns that would limit monitoring the project, which would be the deepest underwater mining project the firm has undertaken, at 450 metres. Rather, it would come down to issues of cost, Steenbrink said.

Duncan Currie, counsel for environmental lobbies Greenpeace, Kiwis Against Seabed Mining and Deep Sea Conservation Coalition, put several critical reports over Boskalis's environmental record to Steenbrink, which the Dutch executive said either hadn't come to his attention or had since been rectified.

Boskalis senior engineer Jamie Lescinski told the committee the modelling used to determine the impact of the plume of discharged sediment from the mining operation took a conservative approach. The plume is expected to be at an average of 10 metres above the sea bed during a mining cycle, but Lescinski said it could probably go as high as 20 metres without any substantial variation.

The impact of the plume and how it disperses the sediment is a key point of contention in the project. Boskalis plans to blast jets of water into the ocean floor to loosen the seabed and suck up sand for separation and extraction of the phosphate, before dispersing it through a hose. Among concerns is whether clay, referred to as chalk ooze and which typically lies below the proposed layer of sand to be mined, would be sucked up into the suction system,

CRP wants to initially mine an 820 square kilometre area for five years before widening its activity to a 5,207 sq km area for up to a further 30 years.

Lescinski said lessons and samples from the initial mining stage would be used to model the potential impacts in expanded areas if the project proceeds to those later stages.

"I would advise that, before mining in a new area, a condition should be imposed that seabed samples need to be collected and analysed and that information should be used in the model as inputs to rerun operational predictions before moving into new mining," she said. "My expectation is it would be similar, but that's an expectation. I would want to see that sediment first and see if there are any similarities to the area that's already known."

Gerard van Raalte, who has been overseeing the project for Boskalis, told the hearing the Chatham Rise project would draw on existing techniques and equipment, but would also need its own bespoke solutions to deal with unique issues.

"What we have developed so far is complex, but in fact it's a combination of state of the art techniques that are applied in a new context," van Raalte said. "We are convinced we have chosen the best available technology with the best environmental practices to mitigate as much as possible what we can do in the design stage."

He said the project will need extensive monitoring in the early stages to ensure it would be able to cope with any unexpected problems that arise.

The hearings are continuing.

(BusinessDesk)