2021 Journal of the Northern Territories Water and Waste Association

2021

Remediation of Waste Sites

PUBLICATIONS MAIL AGREEMENT #40934510

Journal

of the Northern Territories Water and Waste Association Bioremediation at Ekati Mine Site, NWT

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The Journal

TABLE OF CONTENTS

is published by DEL Communications Inc. Suite 300, 6 Roslyn Road

Message from the editor: Ken Johnson ...................................................................... 5 NTWWA Board and support staff..............................................................................

6

Hydrocarbon cleanup at the Ekati Mine site using bacteria...................................8 Tundra Mine remediation project.............................................................................. 10

Soil microbes clean up old Crow fuel spill................................................................ 14

Giant Mine water management................................................................................... 16 Sewage lagoon sludge removal in Old Crow, Yukon.............................................. 18 A framework for water system emergency preparedness in the Arctic...........20 Techniques and technologies for Arctic lagoon assessment............................... 22

COVID early warning in the Arctic with wastewater sampling........................24

Bringing Arctic mine remediation to the community classroom.....................26

Winnipeg, Manitoba Canada R3L 0G5 www.delcommunications.com President & CEO DAVID LANGSTAFF Editor-in-Chief LYNDON MCLEAN lyndon@delcommunications.com Editor KEN JOHNSON ken.johnson@cryofront.com Sales Manager DAYNA OULION Toll Free: 1-866-424-6398 Advertising Account Executives BRENT ASTROPE BRIAN GEROW ROSS JAMES

Sewer main replacement in Iqaluit permafrost.......................................................28

MIC PATERSON

Al Reimer Award winner – Alan Harris, Hamlet of Fort Liard......................... 31

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ON THE COVER – The Ekati Diamond Mine’s remote location comes with many challenges,

including limiting timeframes for transporting waste materials from the site to a treatment facility, and the high costs of transporting these materials. In response to these costs, the Ekati mine management undertook a project to treat contaminated materials in a self-contained, on-site area.

4

The Journal of the Northern Territories Water & Waste Association 2021

Winnipeg, Manitoba Canada R3L 0G5 Email: david@delcommunications.com PRINTED IN CANADA 12/2021

MESSAGE FROM THE EDITOR

KEN JOHNSON

A

situation in Iqaluit has brought to light the critical nature of water emergency planning and the unique responses necessary under Arctic conditions.

I would like to thank Pearl Benyk once again this year for her editorial and plain language review of the Journal articles – this is icing on the cake for my editorial activity of bringing the Journal to press.

If any readers have any questions or comments on the Journal do not hesitate to contact me at EXP (ken.johnson@exp.com or 780.094.9085 [voice or text]). Stay well in the coming year, and with some luck and some good public heath management, I hope to see you in Yellowknife in the fall of 2022. S

s I stated last year, the Arctic is certainly used to change, but 2020 was a milestone year that presented changing circumstances that remain with us today. The current edition (2021) is the 17th edition of the Journal, which has maintained its importance to the NTWWA throughout the past 17 years and gained a new importance for communication with, and a deliverable for association members with the cancellation of the NTWWA Annual Conferences over the past two years. The theme for the 2021 issue of the Journal is remediation, with articles on six remediation related projects in the Arctic. Along with the themed articles, there are articles on sewer COVID testing in the NWT and water emergency planning. The current water emergency

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5

BOARD AND SUPPORT STAFF

Alan Harris, President Hamlet of Fort Liard

Megan Lusty, Vice-president Government of Nunavut

Olivia Lee, Past President Government of the Northwest Territories

Gavin Olvera, Director

Greg Hamann, Director

Kyle Humphreys, Director

Sarah Collins, Director

Rob Osborne, Executive Director

Pearl Benyk, Administrator

Government of Nunavut

Tlicho Logistics

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6 The Journal of the Northern Territories Water & Waste Association 2021

Colliers Project Leaders

HYDROCARBON CLEANUP AT THE EKATI MINE SITE USING BACTERIA

Adding nutrients to the Ekati landfarm soil

Edited from an article by Robert Lacey, Delta Remediation, and Kurtis Trefry, Dominion Diamonds

T

he Ekati Diamond Mine is located near Lac de Gras in the Northwest Territories, approximately 300 kilometres north

of Yellowknife. The mine is only acces-

contaminated materials must be treated.

However, typically these sites have been

Ekati looked for innovative, alternative

located in warmer temperatures than

solutions which could be done on site

those at Ekati Arctic environment, and

and become part of the mine’s operating

these warmer temperatures result in

practices.

faster cleanup of the hydrocarbon-con-

sible by air, except for the brief period of

Ekati decided to clean hydrocarbon-

taminated soils. Also, it has been shown

winter road operation. This remote loca-

contaminated soil by using microbiology,

that soils that have moisture in the range

tion comes with many challenges, includ-

which would make use of bacteria to

of 10 to 20 per cent have healthier com-

ing limited timeframes for transporting

consume (metabolize) the hydrocarbons.

munities of bacteria that consume the

waste materials from the site to a treat-

This method would be cost-effective and

hydrocarbons quicker, which are gener-

ment facility, along with the high costs of

result in soil that meets the appropriate

ally conditions not encountered in the

transporting these materials.

regulatory criteria (Canadian Council of

cold and dry Arctic climate.

In response to these costs, the Ekati mine management decided to under-

Ministers of the Environment [CCME] Agricultural Guidelines).

The formal name for using bacteria to clean up soil is called “land farming”,

take a project which would treat con-

The effectiveness of bacteria at con-

and Ekati set out to determine whether

taminated materials in a self-contained,

suming hydrocarbons has been proven

this method would be effective with the

on-site area. Since Ekati has high environ-

in the cleanup of thousands of contami-

cold temperatures, the extreme changes

mental standards to meet, all spills and

nated sites under a variety of conditions.

in daylight over the course of the year,

8

The Journal of the Northern Territories Water & Waste Association 2021

Final screening process for land farmed soil.

and the dry climate conditions. The initial phase of the project was completed in June 2018 using 1,400 cubic metres of hydrocarbon-contaminated soil. The project made use of a “designer” bacteria contained in a product called Biologix, which is a blend of bacteria with a superior ability to consume hydrocarbons and other chemicals.

Biologix was added to the landfarm soil and evaluated to determine if it was appropriate for the conditions at the mine site (cold temperatures, hours of daylight, and moisture content of the soil). The evaluation was completed by testing the number of hydrocarbons in the soil before and after the bacteria were added to the landfarm. The landfarm also requires the occasion aeration by excavating the pile to hasten the transfer of oxygen into the landfarm soil.

The hydrocarbon-consuming bacteria also need nitrogen and phosphorous nutrients to complete the job, and it was found that the contaminated soil at Ekati did not contain enough nutrients to support the Biologix bacteria. Therefore, in addition to the bacteria, nitrogen and phosphorous were added to the soil to provide the bacteria with all the necessary ingredients to thrive and consume the hydrocarbons.

By September 2019, the 1,400 cubic metres of contaminated soil that was treated by the bacteria and clean enough to meet the regulatory criteria. This

Aerating the landfarm soil at Ekati.

proved that it was not necessary to haul

carbon-contaminated soils can be effec-

the contaminated soil to a treatment

tive in the Canadian Arctic. This method

facility in Yellowknife. Another hydro-

reduces the costs and greenhouse gas

carbon cleanup project was initiated at

emissions associated with screening,

the land farm for 1,000 cubic metres of

bagging, and hauling hydrocarbon-con-

contaminated soil that will ultimately be

taminated soils to Yellowknife for clean-

used as a cap on the landfill site when it

up. Using the Biologix process resulted in

reaches capacity.

a savings of $200 per cubic metre of soil

The project has successfully proven that using bacteria to clean up hydro-

over hauling it to Yellowknife for treatment. S

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(867) 920-4055 The Journal of the Northern Territories Water & Waste Association 2021

9

TUNDRA MINE REMEDIATION PROJECT

By John Mackenzie, AECOM Tundra Mine features of site cleanup.

T

he Tundra Mine site is located approximately 240 kilometres northeast of Yellowknife, NWT, on the east side of Matthews Lake, and ultimately discharges into the east arm of Great Slave Lake.

The site is remote and lies within the Akaitcho Territory, the Wek’eeshii and Monwhi Goga De Nittaee areas of the Tlicho Land Claim Agreement and North Slave Métis traditional lands.

Tundra Mine, owned by Royal Gold, was operated as an underground gold

mine from 1964 until 1968 and supported operations at the nearby Salmita Mine from 1983 to 1987. During its lifetime, Tundra Mine produced some 3,250 kg (104,480 troy ounces) of gold. In 1987, the mine was permanently closed, and in 1999, it reverted to the Crown when the mine’s owner went into receivership.

Crown-Indigenous Relations and Northern Affairs Canada (CIRNAC) is currently the custodian of the site.

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The Journal of the Northern Territories Water & Waste Association 2021

across the Arctic. Historically, mining operations were started with no closure plan in place or funding set aside for site remediation and reclamation when mining stopped. As in many cases, as the profitability of the mines decreased, the owners declared bankruptcy and abandoned the mine, along with all the associated contamination, equipment, and buildings.

After the site became the responsibility of CIRNAC, it was assessed, and a plan was made for the cleanup. The initial phase of the cleanup was started over a decade ago, with tailings and hydrocarbon contamination remediation work completed in the initial phase. During this phase of the project, it was found that two tailings ponds on the site were reaching precariously high levels and the dams were at risk of failing. This failure would result in the release of millions of litres of arsenic-contaminated water, as well as tailings that could potentially contaminate the surrounding watershed for hundreds of kilometres.

This critical situation meant it was urgent to reduce the volume of arsenic-contaminated water in the tailings ponds to reduce the risk of dam failure to manageable and acceptable levels. At this point, 100,000 cubic metres of tailings water was treated so that the contaminant levels were reduced to well below acceptable background levels in the discharge streams. At the same time, this activity eliminated the risk of a dam failure and a discharge of contaminated water into the environment (See article titled “Tundra Mine Emergency Treat-

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ment Challenge” in the 2010 NTWWA Journal).

During this phase, work was also done on the tailings area, which originally included two tailings ponds. In total, over 10,000 cubic metres of hydrocarbon contaminated soils were collected from the two tailings ponds, in addition to debris and waste rock which could potentially acidify rain and snow melt water.

These soils were moved into a central tailings area, which was covered with layers of geomembrane and covered with gravel and sand to protect the liner and control erosion. Placing all the tailings and other contaminated materials into the one tailings area will reduce the potential for surface water to become contaminated, thereby keeping “clean water clean”. Consolidating the materials into one place also limits the actual footprint where contaminated materials still exist on site. Later, the tailings ponds were covered with erosion protection material, and they continue to serve as drainage and flow-through areas for clean surface water.

An important part of the design of the new consolidated tailings area was the installation, through the cover material and

tailings, of ground temperature sensors and instruments to measure the underground water pressure. These monitoring instruments were placed in several locations so the information collected from them would give a good representation of the conditions, in various places and at various depths, of the area holding the tailings. The data collected by these instruments can be recorded at daily or hourly intervals so the conditions of the ground, tailings and ground water can be assessed throughout the seasons.

When the mine was established in the 1960s, the natural drainage path between Mill Pond and Hambone Lake was cut off. Restoring this drainage path, which was done during the latter part of the project, added tremendous value for the natural environment and First Nations’ stakeholders.

When the remedial work was completed in 2018, the Tundra Mine remediation project shifted to a management phase, during which monitoring, and assessments will determine whether the remediation works will withstand the environmental conditions at this site and are performing as expected. This determination will include assessment of both

the remedial work done and the environment downstream from this area.

The accomplishments in each phase of this remediation project at the Tundra Mine site resulted in significant improvements to the site and the surrounding environment. Removing and disposing of hazardous materials off site, as well as the demolition and on-site landfilling of non-hazardous materials and derelict buildings, was a necessary and critical first task to ensure safe work conditions for the public and for following phases of the work.

With the completion of the Tundra Mine remediation project, the immediate risks to the public have been eliminated and the environment is protected in a manner consistent with the Water Licence and Land Use Permit. The design of the project deliberately considered the low maintenance of the entire site in the future, along with the appropriate level of monitoring for the low maintenance framework.

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The Journal of the Northern Territories Water & Waste Association 2021

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SOIL MICROBES CLEAN UP OLD CROW FUEL SPILL Edited from an article by Steven Mamet and Steven Siciliano, University of Saskatchewan

O

ld Crow, Yukon, is a community accessible yearround only by air. Without an all-weather road, construction costs are very high and access logistics are complicated. When unexpected events like hydrocarbon spills occur, the logistical challenges are many and the costs high, not only for assessment of the spill, but also for the cleanup of the spill.

Old Crow is also in an area with complicated geology, including continuous permafrost and associated issues within the active layer. There are no land farms for soil remediation (bioremediation) in the community or nearby. The cold climate limits the biological activity of bacteria activity needed for land farming, and there are various legal requirements regarding land farms in the community.

Microbes will work for food

Drill rig used for site assessment of Old Crow hydrocarbon spill.

14

The Journal of the Northern Territories Water & Waste Association 2021

These various constraints in the community made it necessary to find new and innovative remediation methods to use at sites needing cleanup (referred to as in situ bioremediation). In situ bioremediation uses bacteria already in the local ground to treat the hydrocarbon contaminants in the soil and groundwater.

The local bacteria can be used to treat hydrocarbons in the process of their biological activity because they can adapt to consuming hydrocarbons to obtain the energy to grow and reproduce.

The bacteria get energy from the hydrocarbons by using oxygen to break down chemical bonds in the hydrocar-

Rather than taking microbes out of the soil in Old Crow and testing them in a laboratory, a different process was used. bons. The bacteria “invest” this energy and the carbon from the spill to produce more cells. This process of breaking down hydrocarbon contaminants with the help of oxygen is called aerobic respiration. In aerobic respiration, some of the carbon molecules are broken down to form carbon dioxide and the rest of the carbon is used to produce new cells.

One of the challenges with in-situ bioremediation is that the available oxygen is often quickly used up, and additional oxygen must be added. Fortunately, there are many bacteria that don’t need oxygen to break down hydrocarbons.

These microorganisms need nutrients like nitrate, sulfate, and use iron instead of oxygen to break down the hydrogens. Groundwater can provide these nutrients, but unfortunately, most of the hydrocarbons in a spill sit above the groundwater in the soil. Hydrocarbon breakdown under these circumstances can take much longer to complete.

Part of the solution to this problem is to provide the necessary conditions for the local microorganisms to consume the hydrocarbons. This selection of the right combination of biochemical conditions for the bacteria living in the permafrost soils of Old Crow required some study.

nation. These changes were encouraged by the number of hydrocarbons that were available.

How well did bio-stimulation work?

Measurements revealed that small amounts of nutrients added to the contaminated soil tripled the rate at which the hydrocarbons were broken down compared to the rate in the soil to which nothing had been added. Even with the short warm season in Old Crow, using a bio-stimulatory solution can be predicted to clean up the contaminated site within one to two years, compared to the six to 35 years (depending on which

hydrocarbon is present) that would be required for degradation of the hydrocarbons to occur naturally, with no help.

For a site the size of a small building (3,800 cubic metres), this means that bioremediating the contaminated soil where it is, by introducing nutrients for the microorganisms, would mean more than eight metric tonnes of contaminated soil would not have to be added to the landfill, and this would prevent the emission of more that 30 kilotonnes of carbon dioxide equivalents—as well as reducing costs by 30 to 70 per cent compared to solutions in which the contaminated soil is removed. This led to the opinion that successful and sustainable bio-stimulation processes, in areas where the local ground water contains low levels of organic matter, can be used to remediate hydrocarbon contaminated soils, without moving the soil, even where the temperatures are low. S

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Rather than taking microbes out of the soil in Old Crow and testing them in a laboratory, a different process was used.

Radioactive substances known has radiotracers were used to measure changes in the biological activity (biostimulation) of the microorganisms in samples of soil taken from the location of the contami-

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The Journal of the Northern Territories Water & Waste Association 2021

15

GIANT MINE WATER MANAGEMENT Update to 2010 NTWWA Journal article entitled “Giant Mine Water Management System”

T

Giant Mine Remediation project sign.

he history of Yellowknife is intrinsically linked to its start as a mining town. The two most longstanding and productive mines, the Con and Giant Mines, were a result of the original exploration. Both mines closed underground operations in the early part of the new millennium, but both mines have left extraordinary contaminant legacies on the shores of Great Slave Lake.

The rock mined at Giant was rich in gold and arsenopyrite, a mineral with a

Water conveyance system at Giant Mine.

16

high arsenic content. Extracting the gold from the ore produced by Giant Mine required a “roasting” process to extract the gold from the arsenopyrite rock. Arsenic trioxide dust was created during the production of more than seven million ounces of gold over a 50-year period.

When the ore was roasted to release the gold, arsenic was also released as a gas.

Much of the arsenic gas escaped into the air, but as the remainder cooled, it became arsenic trioxide dust.

Pollution-control hardware installed in the late 1950s prevented most of the arsenic gas from going up the stack, but that created a new problem of storage of the dust. The solution to this storage issue was to make use of the mined out underground chambers. Over a 50-year period, 237,000 tonnes of toxic arsenic trioxide were produced, which is still being stored to depths of nearly 250 metres (800 feet) below ground in various chambers.

Arsenic trioxide dust is water soluble and contains approximately 60 per cent arsenic. It is therefore critical to maintain the stored material “high and dry” to ensure that arsenic is not released into the environment. This effort requires that the ground water level be maintained below the arsenic trioxide dust storage level.

The arsenic trioxide at Giant Mine is stored in 15 underground chambers behind one-metre-thick concrete bulkheads, constructed after the mine closed, which act as plugs to the chambers. Permafrost around the chambers was expected to provide a seal around

The Journal of the Northern Territories Water & Waste Association 2021

the chambers. However, the mining activity thawed the permafrost, and water began seeping into the chambers, becoming contaminated with arsenic, with the potential of leaking into the groundwater around the mine. In response to this new issue, the groundwater has been pumped from the mine to a treatment facility on the surface since 2008.

Over the years since 2008, the contaminated water was temporarily stored in a decommissioned tailings pond over the course of a year and during the summer, the water was pumped into a water treatment plant. The water treatment plant removes arsenic and other contaminants. Once treated, water goes into additional settling ponds for further treatment before being discharged into Baker Creek and ultimately into Yellowknife Bay. This original treatment system is approaching the end of its operating life, and a plan has been developed to replace the water treatment plant and settling ponds as part of a current remediation phase of the entire Giant Mine site.

Once a new water treatment plant is completed in the next several years, the original water treatment plant along with the settling and polishing ponds will no longer be needed.

This site water will continue to be collected and processed at a new water treatment plant when it replaces the existing water treatment system, with the target of ensuring the water is drinkable − containing no more than 10 micrograms per litres (10 parts per billion). The objective is for the new water treatment plant

Profile of Giant Mine water management system.

to reduce arsenic to a concentration well below the “Guidelines for Canadian Drinking Water Quality”.

The $900-million Giant Mine Remediation Project is a job of tremendous scope and complexity, and a 13-year-long consultation process provided the framework for the remediation work, which will include monitoring for a full century into the future.

Most of the details of the cleanup plans have already been reviewed by stakeholders and discussed at length during two technical sessions and a “closure criteria” workshop.

The current phase of the Giant Mine Remediation project began in 2021. S

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17

SEWAGE LAGOON SLUDGE REMOVAL IN OLD CROW, YUKON

Completed sludge and vegetation removal at the Cold Crow lagoon – Geotube dewater area in the background.

Edited from an article by Blair Benn, President, Lambourne Environmental Ltd.

O

ld Crow is the northern-most community in the Yukon Territory, located along the Porcupine River. The community is home to approximately 245 people governed by the Vuntut Gwitchin

First Nation. The community is serviced with trucked water and sewer and the sewage is discharged into a sewage lagoon located west of town.

The Old Crow sewage lagoon is now 30 years old and consists of one rectangular primary treatment cell 10,000 square metres in size. Sewage is discharged at the western side of the lagoon, and there is a discharge control valve in a manhole on the eastern side of the lagoon. The total volume of the lagoon is 17,000 cubic metres, and it has an operating depth of 2.2 metres. The lagoon was built on permafrost with berms of coarse sand and small stones, with silt underneath. The original intention of the design was to use permafrost and water frozen inside the berm material to contain the sewage during most of the year, and to do an annual discharge through a pipe installed in the eastern berm.

The warm temperature of the sewage melted most, if not all, of the permafrost under the lagoon, preventing the freeze back of the berms, and the creation of a barrier to leakage from the

18

The Journal of the Northern Territories Water & Waste Association 2021

lagoon. As a result, sewage slowly filters through the bottom of the lagoon and the berms. This flow condition likely provides partial treatment; however, it also resulted in ponding of sewage around the exterior of the berms, except for the north side of the lagoon. The wastewater naturally flows into a wetland on the east side of the lagoon, which provides supplemental natural treatment. A creek moves the water in the wetland toward the Porcupine River, approximately 300 metres away.

In 2019, Lambourne Environmental Ltd. was subcontracted

by Wildstone Construction and Engineering Ltd. to remove the thick, muddy waste (sludge) and floating vegetation in the Old Crow sewage lagoon by dredging. There are no roads to the community, so all the equipment had to be flown on one of Summit Air’s ATR 72 aircraft. This was challenging because most dredges are too large to be transported by air. The dredge also had to be capable of removing the vegetation floating in the lagoon.

Lambourne designed a dredge which could perform both tasks, and a boat manufacturer designed and built pontoons to float the dredge. The intent was to remove the water from the sludge taken out of the lagoon using Geotubes. Geotubes are large, long “socks” made of a geotextile that allows water to

Operation of the floating sewage lagoon dredge, which removes both sewage sludge and vegetation – Geotube dewatering area in the background.

Loading the floating sewage lagoon dredge on the aircraft in Whitehorse for mobilization to Old Crow.

seep out, while keeping the solid, mud-like waste inside. This

return to the site until mid-July 2020. The equipment which had

was thought to be the best and most portable way of dewater-

been stored in Old Crow was taken to the work site and the

ing the sludge in such a remote location.

crew went to work removing the floating islands of vegetation

A small pumping device for adding a chemical (polymer) to the sludge, and all the equipment, chemicals, and other neces-

covering a good portion of the lagoon and dredging the sewage sludge.

sary materials, were transported to the site in one plane load in

The budgetary cost estimate for the sludge dewatering was

mid-September 2019. A place to lay the Geotubes was needed,

$790,000, which included a mobilization and demobilization

so a bermed area, with a plastic liner, was built along one side of

cost of $200,000; $200,000 for the bermed Geomembrane

the lagoon. The plastic liner captured the liquid (filtrate) flow-

cell; $150,000 for the bermed cell liner and Geotube op-

ing out of the Geotubes and allowed it to flow back into the

eration; engineering costs of $80,000; and a contingency of

lagoon. Once the site was set up, the crew began pumping the

$160,000. The project was successfully completed in August of

sludge into two Geotubes, each 30 metres long. Cold weather

2020, having removed approximately 170 dry tonnes of sludge.

forced the shut down of the project in early October 2019 be-

When the material in the Geotubes has sufficiently dried, it

cause the lagoon began to freeze up.

will be removed and used as cover material at the site and at

Due to the COVID pandemic in early 2020, the crew did not

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Joel Sansome – BC, YT 604-308-0150 jsansome@muellerwp.com

Jordan Webb – MB, SK, NU 204-797-8428 jwebb@muellerwp.com

Dale Robertson – AB, NT 403-589-1699 drobertson@muellerwp.com

The Journal of the Northern Territories Water & Waste Association 2021

19

A FRAMEWORK FOR WATER SYSTEM EMERGENCY PREPAREDNESS IN THE ARCTIC

By Ken Johnson, EXP

In response to a recent water supply emergency in Iqaluit, the residents made use of the potable water available in the adjacent Sylvia Grinell River – boiling of the water was still recommended before drinking the water.

A

rctic communities experience situations associated with natural events such as floods, storm surges, permafrost melt, extreme cold weather, and blizzards.

The costs arising from many of these common emergency situations and their impact on community infrastructure do not specifically fall under emergency preparedness − they are simply part of the means of maintaining safe, sustainable communities in the Arctic.

In addition to these sorts of natural events, there are always accidents and mishaps caused by human activity. In the Arctic, an emergency event can quickly cascade into a more significant situation because of remoteness, limited transportation and infrastructure, communication options and other factors. In general, system failures (water, power, transportation, and communication) and the events that lead to such failures are perhaps the most critical emergencies faced by many Arctic communities.

Emergency responders, whether local or non-resident, are dependent, in these situations, on supply lines. If transportation and communication systems are disrupted during an emergency event in the Arctic, this can complicate matters. Demands placed on communities that can create or intensify an emergency include accommodation, food, fuel, medical services, specialized or heavy equipment, aircraft, vehicles, human resources, and a

20

The Journal of the Northern Territories Water & Waste Association 2021

host of other factors relating to remoteness and climate.

Given that most emergencies are inherently unpredictable, hazard identification is only a tool to aid preparedness rather than a predictive science. There’s considerable variation in the range of perceived hazards in communities as well as across the three Canadian Arctic territories. The sorts of emergency risks that are typically faced by Arctic communities need to be included in any assessment of community preparedness.

Understanding the hazards and risks that Arctic communities face and gathering information from residents, community governments, and other stakeholders is an important step in emergency planning.

When viewing emergency preparedness from an Arctic community perspective, safe communities are far more than the product of the best efforts of any single individual or organization. There is a need to coordinate across many governments and organizations, and this adds considerable complexity to any northern community’s pursuit of safety and capacity to respond to emergency situations.

A framework for emergency preparedness as it applies to a water system emergency may have two parts. The first part can be called a Risk and Resilience Assessment (RRA). Through the RRA, procedures and processes are developed which can be used by the management team to identify the major risks and reduce vulnerabilities of critical assets and mitigate the potential consequences of incidents that do occur. It also guides the community by suggesting (or recommending) countermeasures that can reduce the risk from a threat to the utility’s assets, equipment backup, power, training, and exercises on emergency response plans.

There are six distinct asset categories that may form part of a water system RRA. These categories are the physical and computer elements of the systems and include water source, water collection from source, water treatment, water storage after treatment, water distribution systems and the electronic, computer, or other automated systems that support these asset categories.

Once the facility management team have completed the RRA, this information may be used to create a document that describes the strategies a community can take to aid in the detection of emergency situations. This Emergency Response Plan

Distributing drinking water during a recent Iqaluit water supply emergency required the set up of fill stations, where potable water was available in plastic containers.

(ERP) must describe a system’s strategies, resources, plans, and procedures to prepare for and respond to an incident, natural or man-made, that threatens life, property, or the environment.

The general organization of the ERP can be divided into four sections as follows: • Section 1: Resilience Strategies − strategies and resources to improve the resilience of the system, including the physical security and cybersecurity of the system.

• Section 2: Emergency Plans & Procedures − plans and procedures that can be implemented, and identification of equipment that can be utilized, in the event of an incident that threatens the ability of the community to deliver safe drinking water.

• Section 3: Mitigation Actions − actions, procedures, and equipment which can significantly lessen the impact of an event on the public health and the safety and supply of drinking water provided to communities and individuals, including the development of alternative source water options, relocation of water intakes, and construction of flood-protection barriers.

• Section 4: Detection Strategies − strategies that can be used to aid in the detection of an even natural hazards that threaten the resilience of the system.

The community should review and update their ERP once every five years. The ERP should be thought of as a “living document” with established routine updates, and it must include any revisions to the RRA. S

40 years serving Arctic communities Providing cold region engineering solutions

Let’s explore the possibilities

Contact: Ken Johnson 780 984 9085 ken.johnson@exp.com Photo - Access Vault in Iqaluit

The Journal of the Northern Territories Water & Waste Association 2021

21

TECHNIQUES AND TECHNOLOGIES FOR ARCTIC LAGOON ASSESSMENT

By Renata Klassen, EXP

The Kugluktuk lagoon was constructed in 2008 consisting of a 240-metre and 200-metre cell lined with an HDPE liner. A major issue o ccurred with the formation of “whales” in the liner, seepage from the base of the lagoon and subsidence in the top of the lagoon.

An extensive field program was initiated in 2021 to investigate the potential causes of the lagoon issues and form the basis for remedial work. Site reconnaissance was completed focusing on settlement and drainage issues (See subsidence in top of fence line). Topographic elevations were recorded to help quantify the historical subsidence any continuing subsidence in the berms.

A drilling program was completed consisting of boreholes around the lagoon perimeter to a maximum depth of 10 metres using an air track drill. Samples were collected during drilling of the cuttings returned to the surface.

Laboratory testing on the samples collected included determination of natural moisture content, particle size distribution (gradation), Atterberg limits, and salinity.

Above right: Five of the 11 boreholes were instrumented with thermistor cables to measure ground temperatures and slotted standpipes to measure water levels. The thermistor cables installed in the berms consisted of one ground temperature cable (GTC) and three variable thermistor strings. The installations were temporary by lowering the cables into one-inch solid PVC pipes installed in advance in the boreholes. The five thermistor cables were connected to dataloggers for continuous temperature measurements. Water levels were measured with a water level tape.

22

The Journal of the Northern Territories Water & Waste Association 2021

Another part of the program was collecting water samples around the lagoon to identify possible sewage leaks. Water samples were collected from the anticipated seepage at the toe of the east berm, from and adjacent stream and from a ponded area west of the lagoon.

A permeability test was conducted in the borehole drilled from the western sideslope. A levelogger was programmed and lowered into the one-inch slotted standpipe. The standpipe was filled with water, and the water level versus time was logged. A water level tape was used as a backup measurement. The data has been compiled to provide a comprehensive picture of the ground conditions within the lagoon system to development schematic designs for remediation work.

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The Journal of the Northern Territories Water & Waste Association 2021

COVID EARLY WARNING IN THE ARCTIC WITH WASTEWATER SAMPLING

W

astewater testing has a history of being a source of information for action on public

with the fact that traces of the virus are

health-related issues. Wastewater test-

ment surveillance based on clinical tests

ing has been used to monitor health

and identifying cases of Covid-19 infec-

threats such as polio, illegal drug use in

tion in the community. Wastewater sur-

populations, and, most recently, the vi-

veillance is also a cost-effective way of

rus that causes COVID-19.

detecting COVID-19 in a population.

excreted in feces during all phases of the infection − has led authorities to call for early wastewater testing to comple-

The COVID-19 virus has character-

This way of detecting the presence

istics which makes it challenging to

of Covid-19 in a community alerts the

detect. These include a high rate of

health system five to 10 days earlier

transmission by symptomatic, non-as-

that there are Covid-19-infected people

ymptomatic, and pre-symptomatic indi-

there than testing could do, especially if

viduals that leads to missed detection,

the population includes individuals who

which can in turn lead to the virus being

are infected but have no symptoms or

passed on before it is detected. These

have not yet developed symptoms.

characteristics of the infection − along

24

Laboratory method for testing for viral signal.

The NWT government has undertak-

The Journal of the Northern Territories Water & Waste Association 2021

en regular surveillance of wastewater in some communities within the territory to identify the presence − or absence − of the coronavirus.

Wastewater testing is especially useful for the NWT because it allows public health officials to know there are Covid19-infected individuals in the community and to take early actions to control the virus from spreading. Wastewater testing can’t identify the individuals who are sick, how many people are infected, their vaccination status, or how sick each person is. Unlike swab testing that requires people to sign up, sewage samples include nearly everyone, and if anyone has the virus, it will show up in their waste even before they have symptoms.

The presence of COVID-19 in wastewater samples doesn’t necessarily mean there is active COVID-19 transmission in the community. However, collecting this information can serve as an early-warning system for the territory and help the health and social services system target advice to affected communities.

On the flip side, just because there

are no positive results from wastewater testing in a community doesn’t necessarily mean there are no COVID-positive people there. But the wastewater test gives health authorities useful information to pair with information from tests of individual residents and visitors to the community.

The effort has been led by the Office of the NWT’s Chief Public Health Officer in partnership with the Government of the Northwest Territories Departments of Municipal and Community Affairs, and Environment and Natural Resources. As a key partner, the Public Health Agency of Canada’s National Microbiology Laboratory is providing inkind support of testing costs.

Establishing an early-warning system using wastewater samples provides the opportunity to have a much better idea of whether COVID-19 is present in the territory, and the opportunity to give communities advice and get people tested if they need it.

If there is a positive result from the testing of a community’s wastewater, guidance and outreach may be targeted at those in the community who have arrived in the NWT after travel outside the territory since the last negative wastewater result, as well as those who have developed symptoms of COVID-19.

The detection of COVID-19 in waste-

water samples alone won’t result in ag-

over 67 per cent of the NWT’s popula-

gressive containment measures, as it

tion is being tested for COVID-19 two to

could be connected to imported travel

three times per week.

cases being appropriately isolated. How-

The territory’s wastewater samples

ever, public health measures like putting

are analyzed at the National Microbiol-

limits on large-scale gatherings or mak-

ogy Laboratory in Winnipeg, and at the

ing mandatory masking rules for indoor

GNWT’s Environment and Natural Re-

public spaces may be considered.

sources’ (ENR) Taiga Laboratory in Yel-

Currently, the communities which are

lowknife.

having their wastewater tested for trac-

An investment of $100,000 from In-

es of Covid-19 are Fort Liard, Fort Simp-

digenous Services Canada allowed the

son, Fort Smith, Hay River, Inuvik, Nor-

territory to purchase the necessary

man Wells, and Yellowknife. With these

testing equipment and to coordinate

currently participating communities,

the delivery of this program. S

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The Journal of the Northern Territories Water & Waste Association 2021

25

BRINGING ARCTIC MINE REMEDIATION TO THE COMMUNITY CLASSROOM Edited from an article by Guillaume Nielsen, Yukon University

In Eliza Van Bibber School classroom.

T

he Yukon’s mining industry has been an important part of the Yukon economy since the Klondike Gold Rush 125 years ago. Whether or not a mining operation would leave behind a legacy of damage was not part of the planning for mines in days past, and the Yukon and NWT have been left with many legacy projects that pose serious threats to public health and the environment. The mining industry in the Arctic today recognizes the need for remediation planning at all stages of a mine’s life, along with the need to engage with Indigenous communities that have been impacted by mines.

The newly established Yukon University shares the commitment for remediation planning at all stages of a mine’s life, along with the need to engage with mine-impacted Indigenous communities.

26

In the field with Nacho Nyak Dun students - Keno Hill mine, 2016.

YukonU is committed to working with Indigenous communities and building partnerships to support research that may be applied in a practical context.

YukonU hosts a Natural Sciences and Engineering Research Council of Canada Industrial Research Chair for Colleges (IRCC) in Northern Mine Remediation (NMR). This research program partners with all Yukon’s active mines and focuses on solving environmental challenges the mining industry faces in the North. The program focuses on water treatment by passive or semi-passive technologies, mine waste management, and mine revegetation.

In order to introduce the research program to First Nation communities and build impactful research projects, workshops were held for First Nation summer students, youth, and environmen-

The Journal of the Northern Territories Water & Waste Association 2021

tal teams multiple times each summer between 2018 and 2020. The workshops were hands-on and visually based, focusing on the mine life cycle, as well as mine contamination and solutions to mine contamination. The workshops included experiments performed in the classroom, which helped students explore acid mine drainage, toxicity, and the difference between active and passive water treatment. Some of these workshops were followed by mine site tours with the support of partnering mining companies.

Following one of the workshops presented in the Selkirk First Nation community of Pelly Crossing, a teacher at the community’s Eliza Van Bibber School suggested that the team develop a course that could be offered as part of the science program for the school’s high school students.

With the school’s support and in partnership with Minto Explorations Ltd., the research program team developed a course that highlights the importance of what is referred to as “passive treatment”. Passive treatment systems rely on “mother nature” to provide the means of treating contaminants, with enhancements added to allow mother nature to work better. Passive systems are important for the north because non passive systems require technologies that may require ongoing operation and maintenance attention, including the need for power supply.

The course became part of the credited curriculum offered to students through the Science for Citizens 11 course. The course was built around a class-based experiment where students constructed a small passive-waste treatment system that used Yukon native bacteria and mine-impacted water from the Minto Mine near the community of Pelly Crossing. Sampling, monitoring and discussing heavy metals removal rates were part of each module.

Guest speakers were an added benefit to the course, and they presented information on Arctic research projects, including the impacts of climate on northern mine remediation. Discussions took place around how potentially affected First Nations and communities imagine mine revegetation success in the North.

The course lectures were also designed to present different career paths available in the environmental monitor-

Selkirk First Nation students visiting Minto Mine.

ing field, including a presentation from a Na-Cho Nyak Dun citizen working as an environmental technician at Eagle Gold mine (200 kilometres north of Pelly Crossing) who discussed what she had to do to qualify for the position she has.

Students also heard from a Minto Mine Environmental Officer who spoke about the different groundwater and surface water monitoring techniques and the science behind the mine’s set-up. To explore educational opportunities available to students to prepare them for such careers, students were introduced to the Environmental Monitoring Program at YukonU and this was complemented by a tour of the research lab to introduce students to laboratory equipment.

The students also explored why involving First Nation communities in research projects is important. This discussion was led by a Selkirk First Nation citizen

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working at YukonU as a First Nation Engagement Advisor. Another lecture detailed the exploration-to-development process at Minto Mine to teach students more about the operations at a working mine. Finally, to come back to passive treatment system, a module focused on Minto Mine’s constructed wetland treatment system and its role in post-closure reclamation of the site.

The focus of the course on remediation and restoration, in alignment with the focus of the Northern Mine Remediation research program, has provided a pathway for building relationship with students at the Eliza Van Bibber School.

Both remediation and restoration are relevant to students, emerging areas of interest for the industry, and support advancement of research tools and outcomes that are impactful in the Yukon. S

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27

SEWER MAIN REPLACEMENT IN IQALUIT PERMAFROST

By Chris Keung, EXP

Example of sewer pipe crushing in Iqaluit.

Background

The construction of the accommodation and sealift area of the Crystal II Air Base, now known as the City of Iqaluit, was completed in 1941 as part of the original series of airfields used for ferrying aircraft from North America to Europe. The original service for this area was trucked water and sewage until 1985, when shallow-buried piped services were installed. Shallow-buried sewer pipes are commonly used in Iqaluit. At the time of the installation of the original buried sewer and water system, placing buried pipes in the active layer) was thought to be appropriate. However, with time, it was found the shallowburied service lines could significantly deteriorate from the freeze-thaw forces in the dynamic active layer. In several cases, the forces destroyed the pipe by crushing it.

In 1996, the service pipes between Access Vaults 207 and 208 were replaced.

During this project, it was noted that

28

Project area of Iqaluit sewer replacement.

the ground conditions in the active layer were poor. Changes in the design would be needed for any future construction in the neighbourhood. These would include removing surface and groundwater in the construction trench and installing extra insulation to make sure that warmer temperatures in the pipes would not affect the existing freeze and thaw changes in the active layer.

Sewer depth and alignment

Iqaluit’s municipal guidelines recommend a minimum cover of at least three metres of fill from the top of the pipes to the finished grade of the surface. This is intended to reduce the influence of thawing of the active layer on the pipe, which can cause pipe deformation and complete collapse because of the pressure on the pipe when the thawed active lay re-freezes. Climate change and associated impacts on the active layer may further influence the stability of buried services in Iqaluit in the future.

The current sewer lines have only

The Journal of the Northern Territories Water & Waste Association 2021

between two to 2.5 metres of cover between the top of the pipe and the ground surface. One major problem that affects the possibility of burying this sewer line deeper in the ground is that this sewer line connects to AV211, which then connects to the wastewater treatment facility. Presently, this sewage line crosses over a 2.3-metre diameter culvert. Going under this culvert is not an option because then there wouldn’t be sufficient grade for gravity feed of the sewage at the point where it connects to AV 211. Therefore, to maintain minimum grades and hydraulic flow, the necessary pipe elevation at the AV 211 connection dictates how deep the upstream sewer line must be buried.

The existing water and sewer mains are located at the south edge of Mivvik Street. Replacing the sewer lines in this location raises many issues since this requires working in a very wet area with existing water supply, water recirculation, and sewer mains, as well as multiple

service connections to adjacent buildings. If a new sewer main was placed, in its own separate trench on the north edge of the street, several of these construction problems could be avoided, as well as reducing construction costs and cross contamination risk.

Pipe zone and general backfill

In situations where there are ice-rich or silty soils within a half metre below the specified pipe base, it may be necessary to remove the ice-rich or silty soil below the pipe as the ice could thaw and possibly allow the pipe to move.

The recommended type of material for this area below the pipe should be Example of wet excavation in Iqaluit.

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The Journal of the Northern Territories Water & Waste Association 2021

29

Typical access vault in Iqaluit.

are insulation beneath the steel base of the AV to protect the permafrost below the AV from thawing and the use of flexible couplings to connect the pipes to the AVs to accommodate movement caused by thawing and freezing.

AVs are essential structures that may cost more than $125,000 each. Therefore, finding ways to maintain the existing AVs could provide potential substantial savings. However, considering hydraulic performance, existing conditions of the AVs, and construction factors the installation of new AVs, installing the sewer in a new location as part of the work may be necessary.

Construction considerations

well-graded, sand and/or fine gravel to maintain a dry trench for the pipe. For wet trench conditions, a coarser material such as a well-graded, rounded or partially rounded gravel is preferred as it will help stabilize the trench.

As new sewer lines require pipe diameters of at least 450 millimetres, there may not be enough space in the existing trench to maintain the required spacing requirements between the proposed sewer and the existing watermains. Also, in situations where there are water supply, water recirculation, and sewer mains all in the same trench, it’s best to lay the sewer main on the outside edge of the trench to further reduce the risk of cross contamination.

stalled at least half a metre below the

Access vault considerations

ered.

Access vaults (AVs) are prefabricated, double walled, insulated metal units, in-

30

base of the pipes. The typical temperature in the AVs will be between 5 and 10°C, because of the radiated heat from the sewer main going through the AV. Although the AV bases are insulated to prevent thawing of the materials below the AV, the above-freezing temperatures in the AV may cause some long-term thaw below it. If this happens, the stability of the AV may be compromised because of movement in the surrounding soil which can put additional stresses on the pipe connections outside the vaults.

Breaks in the piping connected to the AVs have been observed in the past. To counter this effect, the thaw stability of the soils under the AVs must be considTwo additional things to consider relating to potential movement of the AVs

The Journal of the Northern Territories Water & Waste Association 2021

As the site is in the downtown core of Iqaluit, this project becomes significantly more challenging. The contractor will be required to safely deal with maintaining access and service to existing businesses, overhead electrical wires, excavation around existing roadways, managing heavy vehicle and pedestrian traffic, and limited workspace within the right-of-way.

If the desired alignment of the new sewer is along the existing sewer alignment, this will require removal and replacement of the existing sewer and likely the watermain pipes. This would significantly increase the project challenges, anticipated construction duration, and construction costs due to the necessity of designing and maintaining a continuous sewer bypass and temporary water supply.

Alternatively, constructing a separate trench for the sewer main on the north side of Mivvik Street would significantly reduce the project complexity, construction duration, service disturbances, and costs. It is estimated that installing the sewer main on the north side of Mivvik Street will result in savings of up to 50 per cent of the project costs. S

AL REIMER AWARD WINNER

ALAN HARRIS – HAMLET OF FORT LIARD Fort Liard Deputy Mayor Eva Hope presents Alan Harris with the Al Reimer Award.

I

am honoured and feel very privileged to have received the

years has led to my success in the water and wastewater field of

nomination and the award in the memory of Al Reimer.

operations. Working with the great people I do, their hard work

In fact, knowing my name was put forward by my fellow

in the provision of municipal services in my own community, and

NTWWA board members is an honour unto itself.

other communities of the NWT, has also, I believe, contributed

I would like to thank my employer, the Hamlet of Fort Liard,

to my success. The water and wastewater services that we are

for their trust and direction in having involved me in this field

all involved with are instrumental to the strength and health of

of work. The training and knowledge I have received over the

everyone around us. Thank you all. S

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31

SACHS HARBOUR WATER INTAKE INSTALLATION

By Ken Johnson, EXP, and Michel Lanteigne, AECOM Sachs Harbour is located along the Beaufort Sea, on the southwestern shore of Banks Island, at 71o 59’ N latitude, and 125o14’ W longitude. It is the most northerly community in the Northwest Territories, 520 kilometres northeast of Inuvik. This small, traditional community has an estimated population of 100 (2016), which is serviced by water and sewage trucks.

Sachs Harbour.

Water supply lake.

Water intake

Installing concrete anchors on insulated HDPE intake pipeline – anchors secured with stainless steel bolts.

32

The Journal of the Northern Territories Water & Waste Association 2021

Preparation for intake installation with removal of ice and excavation of the lake bottom.

Installation of insulated and anchored HDPE using strategically placed heavy equipment – ice platform used for intake installation.

Water intake structure with intake screen, 45-degree bend, bolted connections for fish screen and bend.

The Journal of the Northern Territories Water & Waste Association 2021

33

INDEX TO ADVERTISERS AECOM.........................................................................................................25

MACA............................................................................................................11

Arctic Blaster................................................................................................10

Mueller...........................................................................................................19

Aurora Freightliner.......................................................................................3

NAPEG.............................................................................................................9

AWI (Anthratech Western Inc.)...........................................................IFC

Nexom..............................................................................................................7

BI Pure Water (Canada) Inc......................................................................23

Nunatta Environmental Services............................................................35

Clean Harbors Lodging Services............................................................27

Reed Pipe Tools............................................................................................15

Denso North America................................................................................12

Ron’s Equipment Rentals & Industrial Supply....................................13

Dominion Divers...........................................................................................5

Stantec............................................................................................................24

duAlaska Incorporated..............................................................................35

Terminal City Iron Works Ltd.................................................................17

Emco Waterworks.......................................................................................29 Exp Services Inc...........................................................................................21

Urecon..............................................................................................................5

Harmsco Filtration Products...................................................................31

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The Journal of the Northern Territories Water & Waste Association 2021

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35

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