The shoddy shape of Rankin Inlet’s water treatment and distribution system poses “many health and safety risks that must be addressed in the near future,” warns a Government of Nunavut report.
That’s from a request for proposals issued Nov. 10 by the territorial government, which is seeking ideas for how best to replace the aging water treatment and distribution infrastructure that supports the Kivalliq community of about 2,850 people.
Risks identified by the report include:
• Rankin Inlet’s water storage tank was originally designed to hold one week’s worth of water when it was built in the 1970s. But, due to the community’s growth, it’s now only able to hold a two-day supply. If a problem were to occur with the upstream pump house or pipeline, the report warns “it does not allow a lot of time for repair before the town runs out of water.”
• In 2015, Rankin Inlet faced a precautionary boil-water advisory for two weeks, after tests showed drinking water wasn’t being adequately treated with chlorine. As a stop-gap solution, the raw water storage tank was converted into a treated water storage tank, but the report says that’s no substitute for a properly built system for treating water, possibly including a second stage of disinfection.
• Due to a faulty design, one of the community’s water distribution lines suffers from water pressure that’s so low, it may not be able to support firefighting.
• There’s no gas monitoring at the water treatment plant, as required when working with chemicals like chlorine and fluoride. Inadequate ventilation has resulted in the fluoridation system being taken offline.
• Electrical wiring isn’t up to code. “Most notably, it is not grounded, which is a major safety concern.”
• Asbestos has been found inside one pump house.
Rankin Inlet’s water treatment system “is over 40 years old and is showing its age,” the report states. “The design of the system does not meet current codes and standards, nor does it meet the current and future water needs of the Hamlet.”
Chief among the report’s structural concerns is the state of the Williamson Lake Pump House, which it calls “the heart of the system.” Built in the 1970s, the pump house “has reached the end of its serviceable life,” the report states. Problems include:
• The building’s pipes are corroded and, in some cases, partially plugged by build-up.
• Storage tanks beneath the pump house have in some cases “up to one inch of corrosion,” and a ladder has “completely detached” as a result.
• Valves in the plant don’t work properly, so some areas can’t be shut off for maintenance.
• The concrete housing for the supply pumps is “brittle and is at risk of complete failure.”
• The roof has “integrity issues.”
Rankin Inlet’s drinking water is pumped from Nipissar Lake along a two-kilometre pipeline to the Williamson Lake Pump House, in the centre of the community, where it is chlorinated and stored. From there, water is fed into five loops of buried pipe. Water in the loops continuously flows to prevent it from freezing.
The Williamson Lake Pump House now struggles to support the community, and neighbourhoods fed by two distribution lines are “constantly plagued with low water pressure.”
To cope, the community has taken to opening the return line’s fire flow valve along one loop. “Typically this should only occur for firefighting purposes,” the report states.
The other line that suffers from low water pressure doesn’t have a fire valve, so residents served by this pipe are stuck with low water pressure “and additionally do not have adequate fire protection services.”
The Nipissar Lake Pump House, also built in the 1970s, needs an overhaul. The building is “not weather tight,” and snow accumulates inside. As well, its intake line doesn’t reach the deepest part of the lake, and its intake pumps are near capacity and may not be able to support the community’s further growth.
Consultants hired by the territory would develop plans to replace both pump houses and devise a new plan to treat the community’s water.
The resulting report, which would include cost estimates for this work, would need to be finalized by March 2018, according to the RFP. Interested parties must get their bids in by Dec. 10.
This map shows the path taken by Rankin Inlet’s potable water. It’s first pumped from Nipissar Lake along a two-kilometre pipeline to the Williamson Lake Pump House in the centre of town. From there it is chlorinated, stored and then fed into five loops of buried pipe. (GOVERNMENT OF NUNAVUT PHOTO)