Pingos growing under Inuvik’s hospital pose costly problem
There are pingos growing under Inuvik’s hospital – but that’s not the only problem facing the building, documents suggest, as the GNWT searches for a solution.
Inuvik’s two-storey hospital, resting on adjustable steel posts and concrete footings, opened in 2004 and is expected to last for 75 years. But the foundation has had problems for years, affecting walls and floors above and even jamming an emergency exit.
In a request for proposals, the territorial government now seeks a contractor to investigate and analyze the permafrost beneath the hospital, assess how the foundation is failing, and explore what can be done to fix it.
The hospital is built on permafrost that was supposed to stay frozen using thermosyphons, which extract heat from the ground.
“Unknown until after the installation, the seam welded pipe utilized for the thermal syphon system was defective and started to fail and develop leaks,” the territorial government states in its request for proposals.
“As a result, several of the 64 pipe loops within the foundation lose refrigerant at various rates, which results in reduced cooling capacity of the system affecting the freeze back of the foundation.”
Water in the hospital’s crawlspace is also “penetrating into the granular bedding surrounding the thermosyphon pipes beneath the building” and freezing in the winter, which causes “large ice boils, or pingos” to develop, the request for proposal documents state.
The most recent assessment of the foundation, completed by contractor Tetra Tech last year, provided initial recommendations for monitoring and solving the problem.
The territorial government next wants a comprehensive geotechnical and engineering investigation that will study the current foundation and, additionally, how to better create the foundation for an expansion that would house a long-term care facility.
The Department of Infrastructure, responsible for overseeing the project, did not share a budget for the project in the request for proposals. Tetra Tech’s 2020 report estimated the work could cost between $100,000 to $500,000 to repair or replace broken pipes and at least another $150,000 in other work, including repairs to walls and doors.
Tetra Tech’s report stated: “Sloping floors and cracked walls are aesthetic and maintenance issues that require ongoing repairs. However, the jammed exit door in the acute care wing poses a serious safety issue in case of an emergency requiring building evacuation.”
The company said one of the pingos created by the problems had grown to approximately three metres by four metres wide. The height was not specified.
These issues are not new. A 2008 report by Holubec Consulting, which studied the site in September 2007, found more than a dozen pingos in the crawlspace.
Since there is little slope away from the building, the Holubec report found, surface water cannot drain away from the hospital.