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Environmental & Geotechnical Testing in Ralphs Bay
Information for Residents

RPDC Assessment
The Resource Planning and Development Commission (RPDC) is currently undertaking an independent assessment of the proposed waterfront housing and marina development for Ralphs Bay. The RPDC has produced guidelines for this integrated assessment and asked Walker to prepare a Draft Integrated Impact Statement (IIS) which will address these guidelines. The term integrated assessment means a consideration of environmental, social, economic and community issues relevant to the project.

Environmental and Geotechnical testing
To address the guidelines produced by the RPDC, Walker has commissioned the GeoCoastal Group to conduct sediment testing and geotechnical investigation at the proposed development site. GeoCoastal will use specialist low-impact, environmental coring equipment designed by Dr Trevor Graham to create minimal disturbance. A management plan was prepared for the relevant Tasmanian and Commonwealth authorities and the necessary licence and approvals have been granted.

How will testing be done?

GeoCoastal will use a light, shallow-draft barge designed primarily for seabed environmental investigations. It is different from conventional style coring rigs in that it is designed to remove continuous seabed cores in high-grade stainless steel tubes for chemical testing. The barge is mostly constructed of aluminium (with some steel frame) and when fully configured is approx. 9m long and 7m wide, with a 10m high lifting frame.

The method

Stainless steel tubes are inserted into the seabed using sophisticated vibration-vacuum technology. The tubes are between 63mm (6.3cm)and 75mm (7.5cm) in width, or about the size of a young child’s hand. The method is capable of recovering 100% continuous undisturbed core. No extraneous fluids or water are introduced in the process.

The depth of coring will be determined to an extent by the nature of the sediments encountered in the subsurface, but it is anticipated that cores will be removed from depths in the range of approximately 9 to 20 metres. Once removed these cores will be taken to a laboratory facility where they will be analysed by senior coastal geologists with over 30 years of individual experience and the story of the evolution of the site through geological time constructed. This provides a background framework for understanding the chemical and physical attributes of the site.

How long will the testing take?
The length of time that the coring platform will operate in the bay is dependent partly on weather conditions, but it is programmed to be undertaken for approximately 3 weeks commencing on Friday, June 20, 2008. It is anticipated that the coring platform will occupy one location in the bay per day and, because of the shallow water, will be repositioned by two dinghies rather than a larger vessel. There will be brief periods during the day when a distant jangling sound may be heard, but all noise from the platform should be barely detectable at South Arm Road. Please call the following number for further information: 0458 044 448

When will the barge be operating?
The barge will only be working during daylight hours – between 7am and 6pm Monday to Friday, and 8am to 4pm on Saturdays. At night, the barge will display a security/ navigation light similar to a yacht.

Findings of the research
All research and testing results will be included in Walker’s Draft Integrated Impact Statement and will be publicly available when submitted to the RPDC for independent assessment.

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