ARCHIVED - Part 3 Production, The transmission pipelines
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3.1 What are the
- The temperature of the natural gas going into the pipeline must be controlled to reduce impacts on ground temperatures. This helps to avoid potential damage to the pipeline and the environment. The proposed pipeline route passes through areas with varying amounts of permafrost (see map, Figure 3-1). Ground surface temperature changes with the seasons and along the route. Gas temperature changes as it is compressed and flows down the pipeline. The operating temperature would vary to account for these conditions.
- The natural gas pipeline would operate at pressures of up to 18.7 megapascals (2710 pounds per square inch) and would have thicker walls than most pipelines.
- This design makes it possible to use a smaller diameter pipe than would otherwise be the case. Because of the thicker walls, the pipe would be better able to withstand forces due to ground movement caused by frost heave and thaw settlement.
- The pipeline and right of way would be monitored more closely than most pipelines.
Figure 3-1 Mackenzie Valley pipeline corridor
The companies proposed a one kilometre wide corridor in which the right of way would be located. The exact location within that corridor would be determined after detailed engineering studies if the project proceeds. The detailed route would be subject to approval by the National Energy Board. If anyone objected to the detailed route, there could be a public hearing.
The Mackenzie Valley Pipeline and the natural gas liquids pipeline would be located in a 50 metre wide right of way to Norman Wells. South of Norman Wells, the Mackenzie Valley Pipeline right of way would be 40 metres wide. It would generally follow the route of the existing crude oil pipeline.
How would communities be
affected by the pipelines?
The largest effects on communities would occur during construction. Camps for workers would be located along the right of way and would be “closed.” That is, there would be no unplanned contacts between the camps and the communities.
In addition, construction would require barge landings, storage sites, and roads to deliver pipe, equipment and supplies to the right of way. Heavy equipment would clear the ground, dig the trenches, lay the pipe, weld it, test it and cover it. Nearly all of the work would have to occur in winter, avoiding unnecessary disturbance of vegetation and soils. Most of the roads would be winter roads made of snow and ice.
Communities that currently depend on heating oil and diesel generators would have the opportunity to establish natural gas distribution systems and electric power generation systems. Natural gas would be less polluting than diesel.
During our hearing, we heard many views about a pipeline passing through this huge and largely untouched area where Aboriginal people have lived for thousands of years. Some said they had seen no benefit from the last major industrial activity in the region (the Norman Wells Pipeline) and they wanted a better arrangement this time. The lack of a land claim settlement with the Dehcho First Nations was an issue that many Dehcho said should be resolved. However, other people in the region were enthusiastic about the creation of the Aboriginal Pipeline Group,
September 25, 2006
As we stay here, we do harvesting. We harvest our animals, and we also do our trapping all year round. When you talk about the pipeline like this, it’s going to be right beside us. We know that, and we will feel the impact of it.
April 15, 2010
Unlike other regions in the Northwest Territories affected by this project, the Dehcho Dene have not resolved our outstanding land and self-government relationships with Canada. Our rights with the pipeline access in the Dehcho Territory should be delayed until the Dehcho Process has been concluded. The conclusion of the Dehcho Process with a final agreement would provide the Dehcho Dene with a clear and necessary authority to ensure that this project could only proceed in a manner acceptable to us and with our full involvement in all aspects of the project.
Figure 3-2 Community gas pipeline
Typical pipeline construction activities
- Clearing and grading The right of way is cleared of trees and brush and levelled for construction.
- Stringing Lengths of pipe are moved from stockpile sites on trucks with special trailers and lined up along the right of way.
- Bending Some pipe needs to be bent to the shape of the land so that it will lie flat on the bottom of the trench.
- Welding and coating Lengths of pipe are joined together using mainly automatic welding machines. Every weld is inspected using ultrasound or x-rays so that defects can be detected and removed. The pipe is pre-coated in a factory, but the welds are coated on the right of way to help prevent future corrosion.
- Trenching A trench is dug deep enough to bury the pipe 60 to 90 cm below the surface. The pipe is installed deeper at water and road crossings.
- Lowering Machines with special arms called sidebooms are used to lower the joined pipe into the trench. The pipe coating is checked just before the pipe is put in the ground.
- Backfilling The trench is filled back in, taking special care not to damage the pipe coating.
- Reclamation The land is reclaimed, contoured and revegetated as necessary.
The Aboriginal Pipeline Group includes many communities in the project area. It was formed in 2000 while the companies were still studying the possibility of this project. After more than a year of negotiation, the Aboriginal Pipeline Group signed a Memorandum of Understanding with the companies. The agreement included an option for local Aboriginal groups to own up to one-third of the Mackenzie Valley Pipeline.
The ownership share of the Aboriginal Pipeline Group in the Mackenzie Valley Pipeline would depend on the proportion of gas shipped by companies other than owners of the anchor fields. The minimum ownership share is based on a formula and is expected to be in the range of two to three percent. If the pipeline’s full capacity with three compressor stations were achieved, then the Aboriginal Pipeline Group could acquire up to 33.3 percent ownership in the Mackenzie Valley Pipeline.
December 5, 2006
And when you have—you know, like during the big oil boom—that was the late seventies, I believe a lot of our people were working and came back and, you know, the community was just constantly drinking, drinking, drinking.
And now our young people are—you know, like drinking is put aside and a lot of drugs are starting to show up in our community.
Anywhere where there’s money involved, there’s crime. All you have to do is look at Yellowknife. They made a big public statement, you know, like how many people are addicted to crack in Yellowknife. That’s the same thing that is going to happen with us.
Chief Charlie Furlong
Aklavik Indian Band
January 28, 2006
The Gwich’in desire to become independent from government grants and influence. The Gwich’in desire to be masters of their own destiny. The Gwich’in desire to be self-governing, but we also realize that before we become self-governing, we must first become self-sufficient, and we believe if we are to become self-sufficient, we must take control of our nation, we must develop our resources. We must use those resources and those developments in order for us to benefit and to set up the governing régimes that our people today, tomorrow and in the future will become masters of their own destiny.
The Gwich’in feel that we need projects such as the pipeline, such as the mining industry, future hydro to build a needed capacity. Our people must become managers. No longer should we depend on a non-Aboriginal from down south coming in and telling us what to do.
How would the pipelines
affect land use?
The pipeline right of way would be either 40 or 50 metres wide depending on location. It would be located within a one kilometre wide corridor identified in the applications. The exact route would depend on detailed engineering and environmental studies. The National Energy Board could hold a hearing if anyone objected to the detailed route plan.
The project must conform to land use plans established under the Mackenzie Valley Resource Management Act. Approval from land use planning boards established under the Act is required before any federal agency can issue authorizations for a project. In addition, the companies must obtain rights for access to the land for the right of way and for roads, barge landings, camp sites, borrow pits and other uses.
The Dehcho First Nations have an interim land use plan that includes provision for a pipeline corridor.
Pipeline construction would be carefully planned to minimize impacts to the land. The companies would be required to schedule and locate their activities to minimize noise and disruption to wildlife. Several plans for environmental protection would be developed by the companies for approval by the National Energy Board before construction begins. Wildlife Protection and Management Plans would describe how workers would avoid areas used for bear dens, caribou movement, and sensitive times for caribou feeding and calving. Environmental Protection Plans would direct workers and contractors to measures that would protect the air, water, vegetation, and wildlife during construction. Waste Management Plans would guide the appropriate disposal of waste from construction sites.
The companies, in cooperation with local residents and northern authorities, would be required to monitor the effects of pipeline construction on the land and wildlife. The National Energy Board would conduct its own inspections, monitoring and audits to make sure the companies comply with their plans.
December 5, 2006
As a youth of this community, I often feel we need to listen to our Elders. They are wise. They know. Many of them know we need to make our land our priority. Our land and our Elders cannot be replaced.
When our Land Claims were signed, our leaders said they would protect our land for the future. I am the future. One day, I want to be able to take my children out to my Jijuu’s fish camp and to where she used to go trapping with her dad, but that might not be possible if you build the pipeline. I am not guaranteed that our land will be safe.
September 26, 2006
I wish we could do this in a positive way that no one would get hurt from that oil company taking stuff out of the ground. I was thinking about a fire ceremony, have a fire ceremony, and that way when we go out in the land, we do a ceremony on the fire, and we go out, get berries. We do the same thing to the water, we put tobacco, and when we travel, so nobody gets hurt. So that’s how we would take care of Mother Earth and the land through songs. We’ve got songs for Mother Earth and water, so that the land keeps all our values, that everybody has a value, I think it’s inside the land gives.
The land nourishes you, it takes care of you. So through that ceremony, that fire, everything goes on your side, everything works with you. That’s how we live on the land and—and protect the land. But that’s good. I just wanted to share that with you guys. Mahsi.
would pass through habitat of
boreal woodland caribou,
listed as “threatened” by the
Committee on the Status of
Endangered Wildlife in Canada.
How would fisheries
and water resources
The pipelines would cross 643 water bodies and would be buried at least two metres under them. Special measures would be taken to prevent thawing and erosion on slopes leading down to water bodies.
|Number of Watercourses||Classification||Crossing Method||Description|
|576||Trench||Open cut||Trench dug, often in dry or frozen bed|
|50||Trench||Isolation||Trench dug while water flow is diverted|
|17||Trenchless||HDD||Horizontal directional drilling under water body|
Construction and operation of the pipelines would be planned, monitored and regulated to avoid negative effects on fisheries and water quality. Construction would occur in winter when the majority of northern waterways are frozen.
The gathering system and the pipelines would cross 643 water bodies. These range from seasonal drainages to major rivers. At these crossings, the pipelines would be buried at least two metres below the bed of the stream or lake. This would protect the pipe from threats such as ice jams or shifts in the channel. The main risk to fisheries and water quality would be erosion or other disturbance of the banks.
For most crossings, an open trench would be dug while the water was frozen. In other instances, some water would still be flowing in winter. Barriers would block or divert any flowing water around the excavation during trenching and pipe-laying.
Figure 3-3 Water crossing by horizontal directional drilling
At 17 locations, the pipeline route would cross large, fish-bearing water bodies. At these sites, horizontal directional drilling would be used. A hole would be bored under the river bed, and pipe would be pulled through to the other side. The open cut method would be used if directional drilling does not work at a site.
It is important to control thawing and prevent erosion on the slopes leading down to water bodies—and on other, similar sloping terrain. Thawing and erosion could affect the stability of the slopes and deposit soil in water bodies. Insulation and thermosiphons would be used to reduce or prevent thawing.
Barge traffic, landings, roads and storage areas on or near the
Mackenzie River would be required to comply with regulations to
prevent impacts on water quality and fisheries.
September 26, 2006
It’s going to be a big difference on the river where people are fishing and harvesting at this time of the year. And hunting season happens every year, too, so—well, anyway, but the river and the barges, there’s a little bit of trouble here and there and nothing happening yet, but if there’s a big rush and the barges happen to be moving back and forth upriver, I guess there’s going to be a change into the river system with all the barges running back and forth.
Just concerning about the shallow parts, maybe if it could be done a little earlier during the summer where the water is high, transportation will be a lot easier. In the middle of summer where the water drops, it’s going to stir up a lot of mud and weeds, whatever, in the bottom of the river.
So I don’t know, with a big rush like that, maybe the fish will take an ill effect, and I don’t know about harvesting during the time that people are going to be harvesting their fish for winter. So maybe in between there, where people are harvesting and hunting, I think it’s got to slow down. The traffic has to slow down.
How would the pipelines
be designed to deal with
slopes, permafrost and
The pipelines pass through areas of permafrost. The temperatures of the pipe and the surrounding soil are taken into consideration in the design. The natural gas pipeline would have thicker walls, operate at higher pressures, and be monitored more closely than most other pipelines in Canada.
The Mackenzie Valley Pipeline and the natural gas liquids pipeline have been designed to be strong enough to contain the high pressures of the natural gas and liquids. They are also designed to withstand movement of the ground in which they would be buried.
The entire pipeline route passes through areas with varying amounts of permafrost, ranging from continuous permafrost near Inuvik to discontinuous permafrost near the Alberta end.
The companies proposing the pipelines propose to control the temperature of the natural gas and natural gas liquids at the outlet of the Inuvik Area Facility, at compressor stations and at the Trout Lake heater station. Natural gas would leave the Inuvik Area Facility at an average temperature of -1°C whereas
the compressor stations further south would have average discharge temperatures above 0°C. Natural gas gradually cools as it expands when it travels down the pipe. The design of the Mackenzie Valley Pipeline would account for thawing and freezing soil conditions, the temperature of the gas in the pipeline and the temperature of the ground around it. The natural gas liquids pipeline would operate at approximately the same temperature as the ground around it. To determine how thick the pipe wall would need to be to contain the natural gas or
natural gas liquids, the companies used the same method of design as is commonly used for pipelines elsewhere in Canada, referred to as “stress-based” design. To determine whether the pipeline could safely withstand ground movement, they used another approach known as “strain-based” design. The general approach to the design was to first calculate the wall thickness and grade of steel required to withstand the pressure, and then to verify whether that pipe could withstand the expected movement under a range of conditions along the route.
October 2, 2006
So if you guys really damage the land, I wonder what’s going to happen? There’s going to be some way it’s going to be—some land will be damaged when you’re talking about the pipeline. There’s a road ahead of here and there’s two rivers, and when we were talking about rivers and stuff like that, and it could be damage, too. And those kind of things, we have to worry about them. And even snow and water, we have to think about this.
with ice lens
No visible ice
Figure 3-4 Frost heave
Figure 3-5 Thaw settlement
Melting and freezing of the water in the ground can result in thaw settlement or frost heave and can affect the stability of slopes along the route. Removing the vegetation to build the pipelines would allow the summer heat to penetrate the ground more deeply and lead to thawing of permafrost in the right of way. Climate change could increase the thawing of the permafrost but not as much as the clearing of the vegetation.
As a consequence of this design approach, the pipeline companies would need to actively monitor where and how much the pipelines move during operation, and would need to take corrective action to repair, replace or relocate the pipe where necessary. Monitoring would include flying over the pipelines to observe ground disturbance, reading instrumentation installed at selected slopes, and using in-line inspection tools. The tools collect information as they travel through the pipeline.
Mackenzie Gas Project
April 24, 2006
The operating temperature of the pipelines is more driven by some of the pipeline design considerations in the environment in which we’re working, so we’re trying to strike a balance between thaw settlement and frost heave effects. That’s one of the considerations in our pipeline design.
Figure 3-6 Slope instability
Figure 3-7 Thermosiphon
Thermosiphons, devices which draw heat from the ground, would be used where needed to reduce the rate of thawing and slow ground movement.
Insulation, such as wood chips, could also help protect the slopes or reduce the amount of soil freezing caused by the pipe.
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