By Kelly Foss |
Feb. 8, 2011
In the height of summer, in a small parking lot outside of the Ocean Sciences Centre, a unique project began.
It was the first of three stages in a major upgrade of infrastructure for the Logy Bay research facility. This particular step would see the facility receive a new water intake and involved drilling horizontally for over half a kilometer from the parking lot, under the Centre and out into the ocean to a depth of approximately 35 meters.
This aspect was particularly challenging for the contractor undertaking the work, Michaels Canada Company of Alberta, as well as Memorial’s Facilities Management and the engineering consultant, Hatch Mott MacDonald Inc., who together oversaw the project. It represented the first large diameter horizontal directional drilling project in Newfoundland and Labrador.
The challenges surrounding the project were considerable given that it involved a saltwater exit in rugged rock and a difficult marine environment. Given the novelty of this aspect of the project, a technical paper was written about the process.
The article, authored by Glenn Duyvestyn and John Leonard of Hatch Mott MacDonald, Gary Boone of Michaels Canada Company and Keith Hiscock of Memorial University said: “The design challenges included steep cliffs and rugged slopes along the shoreline, significant wave activity in the vicinity of the exit location, required depths at tie-in locations, the presence of utility tunnels connecting adjacent facilities, a limited staging area for construction, the potential presence of cavities/caves, a 64 metre elevation difference between entry and exit locations and abrasive sandstone bedrock materials.”
The job was not without issue as fractured bedrock near the surface of the initial bore hole caused problems which necessitated a second hole being drilled. Extra care was taken during the drilling of the second hole to ensure a casing was in place to provide support where the fractured bedrock had created earlier problems.
Ultimately, the company was successful in drilling the hole which was then increased to a diameter of 56 centimetres and fitted with a high density polyethylene pipe measuring 35.5 centimetres on the outside and 30 centimetres internally. The space between the pipe and the hole was filled with a grout mixture to hold the pipe in place.
The next stage involves the precision blasting of a wet well and the construction of an overlying pump house that will see the delivery of cold water into the OSC’s facilities. Blasting of the well is expected to begin in the spring with the pump house being completed in the fall.
When finished, the pump house will provide a deep-seawater source that will provide consistent, high quality, low temperature (4-6˚C) seawater on a year-round basis. This will resolve issues with the current near surface, seawater source, which sees water temperatures fluctuate between -1 and 17˚C.
“Our fish disease research requires that the seawater entering our laboratories is of consistent quality and temperature,” said Dr. Matt Rise, an assistant professor at the OSC and the Canada Research Chair in Marine Biotechnology. “A new deep-water source at the OSC will provide the high-quality seawater needed for this research.”
“For deep-sea research on live animals, access to a stable supply of cold, high-quality water is simply essential,” added Dr. Annie Mercier, an associate professor at the OSC. “To achieve this, currently, we have to use powerful chillers in the summer and fall months combined with complex header systems in order to run chilled seawater on flow-through.”
“Not having to resort to in-line chillers makes it much easier, more reliable and more environmentally friendly not to mention less costly. I think that would apply to the maintenance of all live specimens from all depths.”
The new deep-water source will not only alleviate the temperature issues, but also provide increased water volume for improved overall research capacity at the OSC. There will also be enhanced water treatment capabilities including filtration, UV sterilization and ozonation, which are central to holding cold-water organisms and aquaculture species under pathogen-free conditions.
Funding for the project was provided by the Research and Development Corporation of Newfoundland and Labrador, the Canada Foundation for Innovation and the provincial Department of Education, as well as through in-kind support from the Canadian Hyrdographic Service.