Inuvik, NWT - 2010 Utilidor Replacement Program

UTILIDOR IN INUVIK, NWT main title ofREPLACEMENT presentation Ken Johnson subtitle of presentation if required name, designations title

AECOM

UTILIDOR REPLACEMENT IN INUVIK, NWT

Dief the Chief and Inuvik’s Beginnings The Town of Inuvik and its original water and sewer infrastructure were the result John Diefenbaker’s 1950's northern vision. According to some, there has never been a Canadian town so “pondered, proposed, projected, planned, prepared and plotted” as Inuvik. The water and sewer infrastructure is unique to the world, and meets the extreme challenges of geography, climate, and cost.

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Inuvik Infrastructure Sewage lagoon

Summer water supply

Winter water supply

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Inuvik Permafrost •

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Ground is thaw sensitive (warm) permafrost, which means that the temperature of the permafrost is only a few degrees below zero.

Small variations in the ground temperature caused by excavation will cause the permafrost to melt.

Ground is also "ice rich", which means there are significant pockets of ice that may thaw causing significant slumping in the ground.

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Original Utilidor Design •

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Structures on piles prevent heat from warm buildings thawing the permafrost and causing them to sink.

Utilidor was originally constructed in one single enclosed conduit supported on wood piles.

Utilidor included a dedicated pipe carrying high temperature hot water for buildings and freeze protection of the water and sewer mains.

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Utilidor Degradation and Need for Replacement • • •

Wood pile “rotting” in active layer High temp hot water decommissioning 50 year old infrastructure

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Incremental Replacement of Utilidor The “utilidor” infrastructure in Inuvik is being replaced incrementally with modern materials that include metal clad, insulated steel pipe, and steel pile systems. Many portions of the original “utilidor” are still visible throughout the community.

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Backyards of Inuvik – No Room for a Swing Set

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Utilidor Design – Pile Foundation and Board Insulation • • • •

Board insulation protects the existing permafrost.

Piles are placed in stable permafrost a minimum of 6 metres into the ground.

Piles are coated with heavy grease and wrapped with polyethylene to maintain a non-bonding surface for inevitable shifting of the ground.

Piles are backfilled with a sand to promote freezing into the permafrost.

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Utilidor Design – Insulated Pipes • •

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Pipe is an insulated (50 mm urethane foam) steel pipe with a metal jacket covering the insulation.

Water and sewer pipes are structural beams which carry the gravity loads of water, cement mortar lining, the pipes themselves insulation, jacket, fittings and snow and ice.

Spaced of 7 metres has been chosen as a reasonable balance between pile capacity, beam capacity and pile frequency.

Pipes are Schedule 80 (12 mm wall thickness) to provide corrosion resistance, in addition to the cement mortar lining.

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Utilidor Design – Pipe Supports

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Utilidor Design – Pipe Restraint

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Utilidor Design – Expansion Joints

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Utilidor Design – Fire Hydrants

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Utilidor Design – Service Connections

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Original Utilidor Junction Buildings Minor modifications to the utilidor buildings have been ongoing over the years with significant efforts in recirculation for freeze protection and re-insulation.

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Modern Utilidor Junction Buildings Upgrades to the utilidor system have included new buildings a the major junctions of the system to provide recirculation and reheat freeze protection.

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UTILIDOR REPLACEMENT IN INUVIK, NWT

2010 Utilidor Replacement The 2010 replacement program included 180 metres of water and sewer pipe for capital cost of $1.5 million.

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UTILIDOR REPLACEMENT IN INUVIK, NWT

2010 Utilidor Replacement

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UTILIDOR REPLACEMENT IN INUVIK, NWT

Utilidor Replacement Issues • • •

Land use issues Construction cost issues ($8,000 / metre in 2010) Contractor quality issues

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