Environmental Engineering Reference
In-Depth Information
only just begun, although there are no fewer than six large-diameter pipelines already in
operation. The arrangement is for hundreds of gas wells to produce gas for two
processing plants, which will pipe the gas to Europe for sale. Early indicators are that
development activity has had adverse effects on the tundra. Drilling sites were not
initially on pads, resulting in thermal degradation, subsidence and the formation of ponds
due to heat loss from buildings ('thermokarst'). On a much larger scale is the widespread
degradation caused by tracked vehicles disrupting the tundra vegetation cover. Even a
single pass of a tracked
Plate 24.5
For much of its course the trans-Alaska oil
pipeline is above ground. The units on top of the vertical
members are automatic refrigeration systems which maintain
the permafrost around each footing. The design allows the
pipe to move laterally on the supporting beam under the
influence of temperature changes.
Photo: Ken Atkinson.
vehicle over sensitive terrain causes sufficient disturbance to initiate thermal degradation.
The development planned for the three northern peninsulas of north-west Siberia is far
larger than any development planned in North America. In the 1970s there were
proposals in Canada for a gas pipeline to run from the Mackenzie valley to link up with
the natural gas network in Alberta. Owing to an adverse environmental impact study,
