A brand new water treatment plant in the tiny Nunavut community of Cambridge Bay is slated for completion and commissioning in October 2016. The facility includes a new water intake structure, pump house and treatment facility.
"The new plant will give the community a reliable water system," said Matt Follett, a civil engineer in the Iqaluit office of Stantec Inc., which designed the system and supervised construction. "Until now it has relied on water trucks for drinking water."
The supply, treatment and distribution of clean, safe drinking water is a major problem and expense in the Arctic regions of Canada, says Follett.
"The drinking water treatment systems that exist often have been plagued with struggles ranging from improper installations to specialized requirements for operations and maintenance," he said.
Rui de Carvalho, senior vice-president in the Orangeville, Ont. office of engineering consultants R. J. Burnside & Associates Limited, says projects like the Cambridge Bay water treatment plant face many problems that are unknown to engineers and builders who operate in southern Canada.
"A few of the challenges they face are the harsh Arctic environment, permafrost, a short construction season, a shortage of trades and high energy costs," said de Carvalho.
In addition, he says, any design needs to fit the building materials that can be shipped to the north economically, safely and in a timely manner.
"That’s a real constraint on engineers and contractors," de Carvalho said. "In addition, they need to design structures that are simple to operate, because of the lack of trained people and easily replaceable parts in the north."
Cambridge Bay’s old and undersized drinking water infrastructure was built in the 1970s and upgraded several times since then.
But age doesn’t lie and the system had become unreliable and unable to meet future demand from a small but growing community.
Cambridge Bay’s population is expected to increase from 1,600 in 2010 to approximately 3,800 by 2045.
And with the possible addition of a Canadian High Arctic Research Station in the future, Cambridge Bay’s population could grow to as much as 4,000 by 2045.
The current water delivery system, which is owned and operated by the Government of Nunavut in co-operation with Cambridge Bay, is made up of a combination of underground distribution lines and trucked services. It uses three 12,500-litre water trucks, with a fourth truck kept in reserve for emergencies.
The new system is an upgrade to the existing one, which injects chlorine into raw water.
It has several component parts:
— A new intake pump house, with a water truck filling station and enough capacity to provide emergency chlorinated water;
— A new distribution line connected to the existing line;
— New access vaults;
— A new water treatment plant to reduce bacteria, protozoa, and viruses by filtration, coagulation and flocculation, chlorine disinfection and ultraviolet light disinfection;
— A water storage capacity of 600,000 litres; and
— New fire hydrants, which Cambridge Bay didn’t use to have.
Contractor NDL Construction Ltd of Winnipeg has been performing all of the ground and civil works, such as excavation and the installation of the vault and water lines.
Sub-contractor BI Pure Water (Canada) Inc. built the water treatment system and the drinking water storage tank. The packaged system was constructed at the company’s Surrey, B.C. facility and shipped in containers to Cambridge Bay.
The upgrades are being developed in two phases.
In Phase One, a new intake at Watson Lake, the source of the community’s water, was installed.
In Phase Two, which is expected to be completed in the fall of 2016, 1.7-kilometre supply lines from the new intake to the new water treatment plant are being built.
Because Watson Lake is located at some distance from the settlement, its water is relatively free from contamination.
Follett says the new high-pressure water service is benefiting Cambridge Bay in a number of ways.
First, there are some significant financial savings from lower insurance premiums due to better fire protection, and reduced capital costs because the new system eliminates the need for individual storage tanks.
In addition, Cambridge Bay will be able to expand the water distribution system in the future, reducing the community’s reliance on expensive water truck deliveries.