Developing a methodology to assess and improve critical water infrastructure in Canada’s North

INFRASTRUCTURE

Developing a methodology to assess and improve critical water infrastructure in Canada’s North

Drinking and wastewater treatment in remote communities in Nunavut such as Griese Fiord is particularly challenging.

By George W. Thorpe and Ken Johnson

I

nfrastructure and system health after severe disturbances was initially calculated by estimating and managing the risk. Design of infrastructure was limited by the risk focus. Several years ago, this evolved to “Design for Sustainability” and has now advanced into a more comprehensive “Design for Resilience”.

Critical infrastructure (CI) includes processes, systems and services that could cause death, discomfort or destruction if even momentarily disrupted. If it is networked or interconnected, the impact on CI could be magnified.

It is becoming increasingly important in Canada’s northern areas to assess and improve critical infrastructure resilience by developing a methodology for utilizing an advanced engineering design framework, as many factors there are different than in urban areas further south.

It is not easy to identify infrastructure resilience, until after a severe disturbance, 1 | October 2018

when the full recovery time is recorded.

Each system has a specific quantifiable value and quantifying these is key.

A leader in resilience science, Dr. Slobodan P. Simonovic, has researched and advanced many facets of this complex subject. He recommends the move from focusing on disaster risk reduction strategies to focusing on building disaster resilience through effective adaptation actions.

He and his colleagues have worked on the development of a systems approach to quantification of resilience that allows: • Capturing temporal and spatial dynamics of water management.

• Better understanding of factors contributing to resilience.

• More systematic assessment of various measures to increase resilience.

Dr. Simonovic has also developed quantitative dynamic resilience measures, which have two main qualities: inherent (functions well during non-disaster periods) and adaptive (flexibility in response during disastrous events).

Systems resilience, by definition, is the ability of an engineered system to

provide required capability in the face of adversity. Resilience in the realm of systems engineering involves identifying the capabilities that are required of the system, adverse conditions under which the system is required to deliver those capabilities, and the engineering design to ensure that the system can provide the required capabilities.

NEED FOR RESILIENT DESIGN By employing a “Design for Resilience” methodology, infrastructure and systems can quickly return to near normal functionality in the event of severe disturbances. A wide range of shocks and stresses can impact CI. These events might include: damage, loss of power, water, human access, and control of infrastructure due to severe rain, flooding, high winds, lightning, earthquakes, other natural disasters, or even cyber attacks.

In the Arctic, there are additional issues with permafrost thaw, ground slumping, water shortages, distance between communities and communication challenges.

For North of 60 degrees latitude, we

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must also design for longer term climatic influences, including sea level rise, floods, higher temperatures, severe storms, less permafrost, lower river levels, and lower stored water levels due to drought from a warming planet.

“Design for Resilience” combines stakeholder interaction with various engineering skills, as well as disaster experience, risk management, systems design and strategic planning. A major factor is covering the extra capital cost for these sustainable improvements. Some are skeptical about the value of resilience. Can the infrastructure life cycle be extended when integrating higher cost factors such as artificial intelligence, increased design safety factors and system redundancies?

“An Emergency Management Framework for Canada” is a cohesive approach to emergency management across Canada. The document contains an excellent glossary and provides a common understanding of terminology. It also introduces the term “Hazardscape”, which is the cumulative emergency management environment, composed of all hazards, risks, vulnerabilities and capacities present in a given area.

As reported by Ken Johnson in 2017: “In spite of this abundant resource, water can be a scarce commodity, particularly in Northern communities that require a clean source of water year-round. Winter can last eight to ten months of the year, and in winter, most of the surface water is frozen, with ice up to two metres thick covering it. The north is also a desert, with most regions receiving less than 250 millimetres of annual precipitation, most of it as snow.

“Given these fundamental challenges, supply of community drinking water and wastewater treatment in Nunavut is particularly challenging, due to geographic isolation, an extremely cold climate, permafrost geology, extreme costs, limited level of services, and other unique northern community attributes.”

Additional stressors are moving natural and human systems toward their tipping point and that may trigger extremely large responses.

Polar amplification is the phenomenon that any change in the net radiation balance (for example greenhouse intensification) tends to produce a larger change www.esemag.com @ESEMAG

Caption.

in temperature near the poles than the planetary average. Arctic warming is outpacing the rest of the world due to this.

In 2016, for instance, worldwide temperatures were about 1.78o F above normal. Arctic temperatures were more than 3.5oF above normal.

One example of a tipping point in the North is the rising sea level due to polar ice and glacier melt, where it is now at the point of having salt water reach CI and water intakes during high tide. The high seawater level is also causing erosion of soil under waterfront buildings.

Another critical issue is permanent melting of the permafrost. The active layer thickness (ALT) is determined by probing down with rods and the indica-

tion is that it is steadily increasing. Soil which surrounds piles that support buildings will lose its gripping effect as the melt goes deeper. With less frozen permafrost around the piles, building support is reduced and the structure settles.

In the past, pilings were only sunk to a depth of 7 m or less and will soon be vulnerable. Modern pilings are now drilled down to 13 m or more, depending on the structure of the underlying permafrost.

The resilient design future may see deeper piles and could also have more passive refrigerated piles to keep adjacent permafrost frozen year round.

Significant methane and some disease could be unlocked with mass permafrost continued overleaf…

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INFRASTRUCTURE melt. Wildfires can hasten the permafrost melting if the cover brush is burnt, thereby exposing topsoil to the summer sun.

Along with the warmer climate is the inevitable prospect of less snowfall. This snow is required to fill drinking water reservoirs each year when the summer melt occurs. Low water levels have been encountered in several storage reservoirs in recent years.

Some reservoir catchment areas may need to be expanded. It is clear that wastewater recycling would be a positive step to reduce per capita water use.

Another solution is the ancient method of harvesting ice from a frozen lake or river and melting it in the water reservoir during the summer.

Earthquake activity is increasing in some parts of the world. The 1964 Great Alaska Earthquake near Prince William Sound was magnitude 9.2, which is the second largest ever recorded. A 9.0 earthquake hit the East Coast of the Kamchatka Peninsula, Russia in 1952. Several others over 8.0 have hit Alaska in recent years.

The Yukon recorded a 6.0 earthquake in 2014 and Nunavut had one in 2017.

Another possibility is damage from a solar storm. These occur when the sun emits huge bursts of energy in the form of solar flares and what are known as “coronal mass ejections” (CMEs) – streams of charged plasma that travel at millions of kilometres an hour. These send a stream of electrical charges and magnetic fields towards the Earth at a speed of around 5,000 kph, which can damage electronic systems and disrupt communications.

Earth’s surrounding magnetosphere can only protect electrical and electronic systems to a minimal level.

environment and practices to account for current and anticipated effects. This is an extremely important aspect of resilience.

Resilient infrastructure and systems will have reduced failure probabilities, consequences from failures, in terms of lives lost, damage, and negative economic and social consequences, and reduced time to recovery (restoration of a specific system or set of systems to their “normal” level of functional performance).

Resilience for both physical and social systems can be further defined as consisting of the following properties: • Robustness: strength, or the ability of elements, systems, and other measures of analysis to withstand a given level of stress or demand without suffering degradation or loss of function.

• Redundancy: the extent to which elements, systems, or other measures of analysis exist that are substitutable, i.e., capable of satisfying functional requirements in the event of disruption, degradation, or loss of functionality.

• Resourcefulness: the capacity to identify problems, establish priorities, and mobilize resources when conditions exist that threaten to disrupt some element, system, or other measures of analysis.

Resourcefulness can be further conceptualized as consisting of the ability to apply material (i.e., monetary, physical, technological, and informational) and human resources in the process of recovery to meet established priorities and achieve goals.

• Rapidity: the capacity to meet priorities and achieve goals in a timely manner in order to contain losses, recover functionality and avoid future disruption.

Climate change risk assessment can be viewed as a valuable aspect of adaptDEVELOPING THE DESIGN FOR ing and building resilience. This includes RESILIENCE FRAMEWORK the following aspects: The most cost-effective manner to • Risk = (Vulnerability Rating) x (Hazachieve infrastructure resilience is ard Rating) x ((Exposure Rating) through an integrated set of engineering • Resilience = (Intrinsic Resilience) x design guidelines based on collaborative (Hazard Rating) x ((Exposure Rating) stakeholder and engineering knowledge • Dynamic Resilience is the ability to mobilization, available across many areas resist the initial impact to a high degree of expertise. The input of local stakehold- and recover in the desired time. (11) ers is an important part of the process.

(Bruneau, Michel et al.)

Four attributes that can provide a resil- • The Hyogo Framework Assessment ient system are: robustness, adaptabil- (HFA) ranked risk of participating counity, integrity and tolerance. Adaptation tries from five continents. This was is about planning and shifting our built replaced by the UN Sendai Framework

3 | October 2018

Assessment (SFA) of resilience.

• The Dependence Tree Analysis (DTA) method identifies the weight of relationships between several events. This is more accurate than the equally weighted indicators in the HFA method.

• The Intrinsic Resilience Index (IR) uses the SFA score and modifies it using the DTA method.

• The Bounce-Back Index (BBI) is the system’s capacity to adapt to its initial functional state. BBI is the combination of Resilience, Vulnerability and Exposure.

Resilient infrastructure and systems will perform well under severe stress.

There may be a short period of loss of some percentage of function, but this amount is acceptable because normal service will still continue. The performance curve then bottoms out and starts to recover in an orderly manner. Recovery time to total restoration is also a calculation that is predetermined and must be reasonable.

With resilient infrastructure and systems there is a response capacity which is the ability to resist stress, diagnose the status with smart predictive software, and repair or switch to redundant components.

In contrast, when resilience is not designed and built in, performance most often goes close to zero percent after a severe stress and will take a significant amount of time to recover. People would then be without drinking water or electricity, for example, thus forced to fall back on traditional ways of supplying their own water and power.

What is the best methodology for planning for resilience and then building resilience? Figure 6 shows a framework which starts with planning, i.e., determining current threats and hazards, characterizing and analyzing risk, until the resilience options are developed. The plan then needs to have the resilience actions prioritized and implemented. Moving into the building phase, key is funding of these activities, which is a proactive investment for harm reduction by tax payers.

Detailed design for resilience then takes place, followed by construction and monitoring of these improvements to learn from disruptive events. The infinite loop of plan for resilience and build for resilience can continue with new knowl-

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edge and improved methodology.

A new National Standard of Canada (NSC) has been developed to assist northern infrastructure with detailed specifications for design to withstand a changing climate. The first five NISI standards deal with drainage, permafrost and snow load.

Under development are several more standards covering operations, maintenance, fire, high winds and erosion. These standards will start to prepare Canadian infrastructure for an uncertain future.

Engineers Canada has developed, under the direction of the Public Infrastructure Engineering Vulnerability Committee (PIEVC), the Engineering Protocol for Infrastructure Vulnerability Assessment and Adaptation to a Changing Climate. This protocol is a step-bystep methodology of risk assessment and optional engineering analysis for evaluating the impact of changing climate on infrastructure.

CONCLUSION As the impacts of climate change on the North are increasing in frequency and severity, we must confront the new climate reality with maximum speed and collaboration. We need to accelerate progress and promote resilience.

The design for resilience methodology is advanced enough to allow a theoretical foundation for understanding best practice. It will continue to evolve as it is refined by adapting and applying new scientific practices and knowledge.

To achieve northern critical infrastructure resilience goals, experimentation, iterative learning and discovery by stakeholders is required. Development of “Implementation Roadmaps” will assist design teams in their work. Promoting, teaching and implementing the “Design for Resilience” framework should become part of common engineering education and practices.

George W. Thorpe, P.Eng, is with Bi Pure Water (Canada) Inc. Email: georget@bipurewater.com. Ken Johnson, P.Eng, is with AECOM, (References are available on request.)

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