Engineers have applied to begin drilling boreholes in the seabed in George Town harbour for a study to help determine the subsurface conditions in advance of the planned cruise port development.
The results of the geotechnical study, which is expected to take three months, will likely influence the design of the piers.
It will determine, among other things, the stability of the rock beneath the seabed.
It is one of a number of studies that need to be completed before a final contract can be signed between government and the preferred bidder on the project, Verdant Isle Port Partners.
Any final agreement is also contingent on the result of an upcoming people-initiated referendum.
In spite of the looming vote, government and its partners are proceeding with some of the advance studies as part of an ‘early works agreement’ with the preferred bidder. The borehole work is not scheduled to be undertaken before the referendum, a Ministry of Tourism spokesperson said in response to questions from the Cayman Compass.
The geotechnical study will involve drilling 20 small boreholes to a maximum depth of 45 metres (145 feet) below the surface, according to a Coastal Works Application submitted by McAlpine, one of the partners in the Verdant Isle group, and viewed by the Cayman Compass.
The boreholes correlate approximately with the planned placing of the piers, according to a map submitted with the application.
The work will be performed from a 400‑foot drilling platform supported by a ‘jack-up barge’ and is likely to have some impact on boat traffic in the harbour. Much of the work is expected to take place at weekends and outside peak hours for commercial boat traffic, the application notes.
It states, “The application is to carry out necessary testing to obtain data to inform engineering methods in the construction of the Cruise Berthing Facility.
“The data collected from this work will serve to refine the facility design as well as to help guide the development and implementation of environmental protection programs that best fit the local conditions, and to assist in the decision of constructing the cruise dock application.”
The application notes that there should be no “turbidity concerns” and indicates that work will be stopped if turbidity plumes are detected.
The geotechnical study is one of a number of studies, also including a completed environmental impact assessment and dive surveys of the harbour, that fall under the ‘early works agreement’ – a schedule of work required to be completed by the bidder, Verdant Isle, in advance of finalising a contract.
The results of those studies are expected to impact the design considerations and will be factored into negotiations over a final contract, if the project gets the go ahead from the public when a referendum is held.
Some of those studies are expected to begin ahead of the vote.
“The proposed studies to be undertaken prior to the referendum are dive surveys to map and grid the existing corals and coral relocation sites, as well as bathymetric and hydrographic surveys of the seabed,” the ministry spokesperson said.
Bathymetric and hydrographic surveys typically involve measurement of the depth of water, as well as mapping of the underwater features.
“This work is necessary to provide information that is relevant to the environmental process, as well as to the public,” the spokesperson said.
She said the environmental consultant being proposed by Verdant Isle is being submitted to the Environmental Assessment Board for approval. The environmental process, an update of the environmental impact assessment carried out in 2015, will then commence.
The spokesperson said Verdant Isle is responsible for the studies, along with their consortium partners, Baird – the environmental consultant who undertook the 2015 EIA – coral relocation firm Polaris and dredging contractor Van Oord.
She said the rationale for continuing with the environmental works ahead of the vote was “to provide further reassurance to the public regarding the intended stewardship and care of our environment” and to continue with detailed work stages needed to inform the final agreement.
Linda Clark, a representative of the Cruise Port Referendum Cayman group, who viewed the coastal works application this week, said it was unclear from the document what the terms of reference were for the study. She questioned if seismic studies and sediment impact would be part of the work.
She added, “Who will own the data obtained once the research has been conducted? As well as to understand the specific risks of the Cruise Berthing Facility construction, any sampling of the bedrock is in the public interests to better understand the geological history of Grand Cayman, and to minimise duplication of similar sampling which would further impact our fragile coral reef ecosystems, as well as incurring additional costs. The results of the survey must be a matter of public record and not owned by McAlpine or any other private party.”
The original environmental impact assessment indicated more detailed sub-surface information was needed both to determine the extent of environmental impacts from dredging and to support detailed design.