Good Engineering Practice for Northern Water and Sewer Systems

2.0 PIPING
2.1 INTRODUCTION
Municipal piping systems in Canada’s North have a relatively short history. One of the earliest
examples was a system using wood-stave pipe installed in Dawson City, Yukon in 1904. In the
NWT and Nunavut, systems have only been in place for some 50 years – 1948/49 in Yellowknife
and during World War II in Norman Wells as part of the Canol pipeline.
In the NWT and Nunavut, the piping systems developed in different ways in different areas.
In the southern Mackenzie (Yellowknife, Hay River, Fort Simpson, etc.) buried pipes, similar to
those in the south, have been in use since the first systems were installed and continue to be used
to the present. The major changes have been to utilize modern pipe types and polyurethane
insulation, as they became available. Prior to the availability of polyurethane insulation, there was
little use of insulated pipes, although early Yellowknife pipes were surrounded by peat in an
attempt to limit heat loss.
More remote areas, such as Iqaluit, Rankin Inlet and Inuvik, initially utilized a mix of buried piping
and above grade utilidors. The utilidors were initially insulated wood or metal framed structures
containing not only water and sewer but also, in many cases, heating lines that conveyed high
temperature hot water from a central heating plant for building heat. These utilidors had high
maintenance costs and high heat loss. Current practice is to utilize separate insulated pipes, in
both buried and utilidor applications, and to limit the use of utilidors to those areas of sensitive soil
conditions. The major central heating plants in Iqaluit and Inuvik have been abandoned in favour
of individual building heating systems.
2.2 MATERIALS IN USE
A variety of pipe types have been used, including:
• Wood-stave Limited historical use in Yellowknife and Pine Point.
No longer in use.
• Cast Iron No longer produced. Production ceased when
ductile iron became available. Cast iron remains in
use in Yellowknife and Hay River.
• Ductile Iron Currently used in Yellowknife and Rae Edzo for
new construction.
• Corrugated Metal Pipe (CMP) for
Storm Sewer
Routinely installed for storm sewers and for
drainage culverts.
GOOD ENGINEERING PRACTICE 2-1 Apr-04
Piping