Aurizon and GVK Hancock queries use of Dredge Spoil for Railway embankments

Queensland: It is reported that freight rail company Aurizon has raised concerns about the Queensland Government’s proposal to use dredge spoil for railway embankments at the Abbot Point expansion project.

The company has an agreement to build a rail line from the port, between Townsville and Mackay in North Queensland, to coal fields in the Galilee Basin.

The plan to use dredge material to build rail embankments and a land reclamation area for port activities has been proposed by the state’s Department for Infrastructure and Planning, but Aurizon used its submission to the Environmental Impact Assessment to question whether enough is known about the dredge material at Abbot Point

It is relatively common for dredge material to be used to build new land formations at ports.

However, Aurizon said that it does not know if the proposal to use dredge material for rail embankments would work, because not enough was known about the dredge material that will be gathered at the project.

Aurizon said in its submission to the department that “In Aurizon Network’s opinion, bund wall design requirements vary greatly from railway formation design requirements, and it is not clear to Aurizon Network that due consideration has been given to these dynamic and differing design requirements.”

The company also said that there could be problems if more rail lines to service future projects in the Bowen and Galilee Basins need to be built over the reclamation area where dredge material would be used as fill.

The submission said that “If any narrow gauge expansion is required to be constructed on top of areas where spoil has been beneficially reused, significant project delays of some years will ensue as a result of land being required to stabilise, again leading to an increase in costs.”

Aurizon said that those delays would add to price paid by mines for transporting coal, affecting the viability of new projects.

ABC last week asked Aurizon to elaborate on the comments it made in the submission but the company said that it was too early to ‘delve into that level of detail’ and was glad of the opportunity to work with the department to resolve the issue.

GVK Hancock, one of 2 coal companies aiming to build terminals at Abbot Point, has also raised concerns.

In its own submission, GVK said that it was still unclear how dredge material could be used at the project.

GVK said in its submission that “Whilst the Preliminary Documentation suggests some of the dredge material is suitable for beneficial reuse such as general fill for the terminal sites, this is yet to be confirmed.”

GVK did not respond to requests for further comment.

Mr Jeff Seeney, Queensland Deputy Premier, said that the Government was dealing with the issues raised by GVK and Aurizon.

He said that “Since those submissions were written the State Government has met with both companies and will continue to work with them to ensure their concerns are addressed. Dredged material has been used to support the creation of port land and associated infrastructure with great success at the Port of Brisbane and elsewhere. We are confident our proposal provides the best protection for the reef, considering the alternative is for that material to be dumped in reef waters.”

Professor Mr David Williams, from the University of Queensland, is an expert on geotechnical engineering, particularly in the resources sector.

He hasn’t examined the Abbot Point project specifically, but said using dredge material for embankments is possible, depending on the make up of the material at the location.

He said that “The thing to remember about dredge spoil is that it is not all fine. It seemed to me that there is some fine material and some course material. Obviously the coarser material would be more suited to such an engineering construction than the fine.”

Mr Williams said that virtually any engineering project of this nature can be done, depending on how much money is available.

While he did not know what know what data was available so far about the dredge material available, he said that it ‘sounds unusual’ that 2 companies like GVK and Aurizon had not been presented with the data yet.