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Integrating biofiltration into existing water plants
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CONTENTS
October 2021 • Vol. 34 No. 5 • ISSN-0835-605X
Editor and Publisher STEVE DAVEY steve@esemag.com Managing Editor PETER DAVEY peter@esemag.com Sales Director PENNY DAVEY penny@esemag.com ales Representative DENISE SIMPSON S denise@esemag.com Accounting SANDRA DAVEY sandra@esemag.com Design & Production MIGUEL AGAWIN miguel@esemag.com Circulation BRIAN GILLETT ese@mysubscription.ca
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TECHNICAL ADVISORY BOARD
Archis Ambulkar OCT Water Quality Academy Gary Burrows City of London Patrick Coleman Stantec Bill De Angelis Metrolinx Mohammed Elenany Urban Systems William Fernandes City of Toronto Marie Meunier John Meunier Inc., Québec Tony Petrucci TMIG The Municipal Infrastructure Group Environmental Science & Engineering is a bi‑monthly business publication of Environmental Science & Engineering Publications Inc. An all Canadian publication, ES&E provides authoritative editorial coverage of Canada’s municipal and industrial environmental control systems and drinking water treatment and distribution. Readers include consulting engineers, industrial plant managers and engineers, key municipal, provincial and federal environmental officials, water and wastewater plant operators and contractors. Information contained in ES&E has been compiled from sources believed to be correct. ES&E cannot be responsible for the accuracy of articles or other editorial matter. Articles in this magazine are intended to provide information rather than give legal or other professional advice. Canadian Publications Mail Sales Second Class Mail Product Agreement No. 40065446 Registration No. 7750 Subscription Changes? Please email reader subscription changes to ese@mysubscription.ca, or call 705-502-0024. Environmental Science & Engineering 220 Industrial Pkwy. S., Unit 30 Aurora, Ontario L4G 3V6 Tel: (905)727-4666 Website: www.esemag.com A Supporting Publication of
FEATURES 6 8 10 14 16 20 24 30 32 34 36 38 39 40 42 44
If it isn’t broken, don’t try and fix it Ontario faces $52 billion infrastructure repair backlog, report finds Wastewater treatment plant modernized to prepare for growing population Managing constituents of emerging concern in drinking water Quebec landfill gas to be used as a renewable energy source Hamilton restores aging watermain sections following friction loss testing Field-testing now complete on mobile district metering project to cut water losses The detrimental effects of combined sewer overflows and COVID-19 Home flood protection program empowering homeowners to take action Remote B.C. village finally gets a safe, reliable drinking water system A new approach to construction allows for smaller valve vaults Microbes biodegrade diesel fuel in Labrador Sea, study finds Algal bloom toxicity harming fish year round, U of G study finds Improving ammonia removal at a petrochemical plant's wastewater lagoon Aquifer recharge rates can affect landfill leachate plume migration rates Geomembrane solves waterproofing challenge in difficult underground installation
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Integrating biofiltration into existing water plants to improve contaminant removal Emergency response planning necessary to protect corporate assets FAQs about level and pressure measurement technology for wastewater treatment Thermal hydrolysis boosts biogas production from biomass
DEPARTMENTS
56 Product Showcase 59 Environmental News 59 Professional Cards 61 Ad Index
www.esemag.com @ESEMAG 4 | October 2021
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Environmental Science and Engineering Magazine
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EDITORIAL COMMENT BY STEVE DAVEY
If it isn’t broken, don’t try to fix it
A
s a lot of us did in the 1970s, I too desperately wanted my own car, which was a ticket to freedom, and seemingly a right of passage into pending adulthood. So before starting Grade 11, in 1978, I purchased a 1970 Oldsmobile Delta 88 convertible. Like all cars of that era, rust had taken a toll on the body, and in this case, only the hood and front of the car were unaffected. Using a summer job’s worth of income, I had the first of what would be many body and paint jobs done. The result was not perfect, but it turned the Olds into a respectable ride. While the body had been rough, the car’s engine ran perfectly, and it had a new exhaust system put in before I bought it. But to me, the stock muffler sounded too tame. I really wanted to increase the “cool” factor of the car and give it a more high-performance exhaust note. So, I decided to cut off and replace the stock muffler and tail pipe with a “Cherry Bomb” muffler, which was essentially a tube with minimal noise baffles. This decision proved to be disastrous. The “Cherry Bomb” muffler didn’t sound great on my car, and was too large for the exhaust pipe, so fumes leaked out constantly. To add insult to injury, my placement of it in front of the rear axle allowed hot exhaust to heat up the wheel bearing, causing it to fail prematurely. In the end, I had to purchase and install a new wheel bearing, as well as a new muffler and tail pipe. All for nothing, but a valuable life lesson was learned. If it isn’t broken, don’t try to fix it. Prime Minister Justin Trudeau calling a snap $600 million federal election reminded me of my teenage folly. In Trudeau’s case, his party went in to the election leading a minority government with 157 elected MPs. After the election, he still is leading a minority government, with 158 elected MPs. This works out to $600 million for one additional seat. The day after the election, the Bennett Jones Governmental Affairs and Public Policy group held a webinar called “What's Next for Canada Post-Election 2021”, featuring panelists John Manley, who served as deputy prime minister of Canada from 2002 to 2003, John Baird, who served as federal environment minister from 2007 to 2008 and minister of foreign affairs from 2011 to 2015, and former British Columbia Premier Christy Clark. “What does a second Liberal minority government mean environmentally?” was among the many topics discussed by the panel. Christy Clark said she felt that being in a minority government situation again, has weakened the Trudeau government’s position with the other parties, specifically the NDP. The Liberals can no longer use the threat of an election if other parties don’t approve their initiatives. This will pressure them to follow the NDP’s environmental ideas, which can be very anti energy sector. For example, Canada’s energy sector may face stricter 6 | October 2021
In 1978, I purchased my 1970 Oldsmobile Delta 88, which I still enjoy driving to this day.
environmental restraints, that will make it harder to get product to market. Clark says that we need a vibrant energy sector, to provide employment and create wealth, which helps pay for social programs all Canadians need. Also, giving Indigenous communities a financial stake in future natural resource projects, can be a key part of the Truth and Reconciliation process. “You don’t solve poverty with apologies, but with the creation and sharing of wealth. If the energy sector gets killed by over-regulation or deliberate government policy, we lose the ability to truly reconcile with Indigenous people,” stated Clark. She also said that other provinces should use the B.C. carbon tax model, which has cut fuel consumption and is revenue neutral. Moreover, all the funds collected are being put back into growing the province's economy. On this note, John Baird said he thinks that carbon pricing will continue to rise, as Canada tries to meet its Paris Accord targets. John Manley said that key companies in Canada’s oil sector have made extraordinary progress in reducing greenhouse gas emissions and are now some of the cleanest producers in the world. He said that Canadians need to remember that, if the world can’t have access to Canadian energy sources, it will look elsewhere. All of the panelists felt that Canada has a bright economic future, but only if we continue to be able to export our natural resources in a reasonable and timely manner. Finally, the overall feeling of the panelists seemed to be that wasting hundreds of millions of dollars on an unnecessary election, along with valuable political capital, served no one’s interest. Steve Davey is the editor and publisher of ES&E Magazine. Please email any comments you may have to steve@esemag.com Environmental Science & Engineering Magazine
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INFRASTRUCTURE
Ontario infrastructure has $52B repair backlog, FAO report finds
F
orty-five percent of Ontario’s municipal infrastructure is not in a state of good repair, suggests a new report from the Financial Accountability Office of Ontario (FAO). The current cost to bring those municipal assets into a state of good repair, and eliminate the municipal infrastructure backlog, is about $52 billion, the report states. The FAO, which provides independent analysis on the state of the province’s finances and trends in the provincial economy, compiled a sector by sector breakdown of the assets in Ontario’s 444 municipalities. On a sector level, municipal roads represent the largest share of the infrastructure backlog cost at $21.1 billion, followed by “other” buildings and facilities such as government administration ($9.5 billion), wastewater ($7.3 billion), potable water ($5.3 billion), bridges and culverts ($4.3 billion), stormwater ($3.8 billion) and transit ($1 billion). In addition, there is some $47 billion of municipal assets with an unknown condition, the report states. The FAO says that maintaining public infrastructure in a state of good repair is generally the most cost-effective strategy over an asset’s life cycle and that postponing repairs raises the risk of service disruption and increases costs. “Keeping assets in a state of good repair helps to maximize the benefits of public infrastructure, and ensures assets are delivering their intended services in a condition that is considered acceptable from both an engineering and a cost management perspective,” the report states. To assess whether assets are in a state of good repair, each asset’s condition was compared against standardized performance targets provided by the Ontario Ministry of Infrastructure and further developed by the FAO. Municipalities have until 2024 under provincial law to develop detailed inventories on municipal assets like infrastructure. In terms of Ontario wastewater infra8 | October 2021
A new report from the Financial Accountability Office of Ontario breaks down the state of assets in municipalities across the province. While wear and tear remains visible under the Gardiner Expressway in Toronto, (pictured), the city tops the provincial list for the highest number of assets in a state of good repair. Credit: Reimar, stock.adobe.com
structure, the report estimates a current replacement value of $94.3 billion. Approximately 32.7% of wastewater assets are not in a state of good repair, the report found. Overall, municipalities own an estimated 753 lift stations, 1,817 pump stations and 337 treatment plants. About $71.1 billion of the replacement value accounts for sanitary forcemains and sewer pipes of various sizes. The wastewater sector, however, is one of the strongest sectors in terms of having a high percentage (67.3%) of its assets in a state of good repair. For stormwater infrastructure, the situation is very similar to wastewater, with 32.7% of assets not in a state of good repair, and 67% in a state of good repair. “In addition, the stormwater and wastewater sectors have a significantly higher share of assets without any condition information, which increases the uncertainty associated with the state of repair of these assets,” the report states. Potable water infrastructure fared significantly better with just 31.5% of those
assets not in a state of good repair, making it the best score on the FAO list. As far as the sector with the most amount of assets not in a state of good repair, the FAO report points to “other” buildings, which can include social housing, waste management facilities, government administration buildings, as well as tourism, culture and sports centres. More than 58% of these structures are not in a state of good repair, the FAO found. Roads came in next on the list with 56.2% of those in Ontario not being in a state of good repair. The FAO report also broke down the state of assets by region. The region with the largest share of assets in a state of good repair is the Toronto economic region at 62.3%, which is 7.6 percentage points higher than the provincewide average. In contrast, the Ottawa economic region has the lowest share of assets in a state of good repair at 38.7%, 16.1 percentage points lower than the provincewide average.
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WASTEWATER
Wastewater treatment plant modernized to prepare for growing population By Steve McDowell
C
ities across Canada are experiencing a growth trajectory, but it is not the cities you may think. A recent report from Statistics Canada noted a record number of Canadians left major urban centres in 2020 in favour of the suburbs and surrounding municipalities. While the move away from big cities is not a new pattern, COVID-19 accelerated the trend to an all-time high. This, coupled with increased immigration and booming real estate markets, means all municipalities, regardless of their size and location, must be prepared for population growth. This is often easier said than done. While Canada’s growing population presents several opportunities, it is not without challenge. Many municipalities are not prepared for this influx of people, lack the necessary infrastructure, or are dealing with aging infrastructure. These factors prevent municipalities from fully supporting their citizens today, and into the future. A 2020 report from KPMG said it best: “The clock is ticking on Canada’s municipal infrastructure.” The report found 13% of the country’s core municipal infrastructure assets, such as roads, pipes and water treatment plants, are in significant decay. They are either unreliable or entirely unfit to meet current needs, let alone the population growth Canada expects to see in the coming decade. Small municipal budgets and unpredictable weather only contribute to this growing challenge. Throughout the COVID19 pandemic, many municipalities were forced to reallocate funds from their already strapped budgets to support the health and safety of their citizens, further exacerbating the issue of finding the money needed to make these infrastructure upgrades. Additionally, climate change has greatly affected weather patterns, making it more severe, unpredictable and a greater threat to already aging infrastructure. The caveat to building strong communities is equally strong infrastructure. Inaction is simply no longer an option. Municipalities must enthusiastically support and prioritize modernization projects. It is vital to not only ensure success for communities now, but to support their growth and prosperity well into the future. Municipalities best prepared to support this growth will be the ones thinking about how to use digital transformation to make smarter decisions, effectively manage their energy usage and be better prepared for potential disruptions. 10 | October 2021
Schneider Electric updated the existing buckets with the latest technology, including Ethernet communications, to source data from the pumps and motors for energy efficiency, process optimization and preventative maintenance.
While hospitals, schools and roadways are often the first systems prioritized in a long list of must-haves, water treatment facilities are of equal importance. All communities, regardless of their population, depend on safe, reliable drinking water. This is not possible without well-functioning water treatment infrastructure. Not only do inefficient treatment facilities mean wasted energy, but they also lead to wasted water and wasted revenue, which, when discussing the difficulties of municipal budgets, only contributes to the existing problem. That said, there are promising developments in the form of government commitments to invest in such upgrades. In Winkler, Manitoba, all three levels of government have committed $73 million in funding for upgrades to the regional wastewater treatment system. Recently, the governments of Canada and Quebec announced the construction of a new water treatment plant in Drummondville, which will not only meet the needs of the community but also create new jobs and help stimulate the economy. While this news is a step in the right direction, it reflects only a couple of municipalities across Canada. For many municipalities, there are still several barriers to overcome. When you consider the fact that water treatment is not a visible issue for continued overleaf…
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WASTEWATER the average citizen, it is easy to see why other projects often take precedence. But in this instance, the cliché “if it’s not broke, don’t fix it” doesn’t apply. Municipalities must act now to experience the short-term and long-term benefits. The positive news is that advancements in digital technology and systems mean that critical facilities like water treatment plants can modernize without the upfront capital expenditure (capex) investments you may expect. The Town of Midland, Ontario, is one municipality that has recognized this and acted. Midland’s water treatment facility is similar to many other municipalities across the country. At 35-years old, it was in desperate need of an upgrade. In this case, the town’s dated system was incapable of providing data collection, monitoring and analysis, something staff depend on to properly manage their energy needs and have confidence in the system’s uptime. Located on the shore of Georgian Bay, estimates predict the population of Midland will increase by 25% to 22,500 people by 2031. As such, the town saw a clear need to update its system now, rather than wait. As the number of residents in Midland continues to grow, demand on infrastructure will too. As a result, the town is committed to “Building Midland’s Future,” which includes upgrading key infrastructure like its water treatment plant. To deliver on this, Midland partnered with Schneider Electric to implement its EcoStruxure solution within its existing infrastructure. Equipping staff with easy access to data and information supports smarter energy management and enables decision-making grounded in real-time insights. The project included upgrading the plant’s SCADA system and installing integrated new connected products and screens to better monitor the facility’s systems. At its core, EcoStruxure collects, stores and filters data, letting workers harness it remotely. By transforming this data into actional information, organizations can save on labour and maintenance costs, while performing at their best. Using digital tools to improve visibil12 | October 2021
The main PLC was upgraded to a hot standby system, so that if one system loses a power supply or main controller, the other one kicks in immediately.
Upgrading something as small as the facility’s motor control centre can exponentially improve the performance and outcome. In Midland’s case, it brought the technology of the plant forward 15 to 20 years, without requiring major capex investment. Energy consumption was reduced between 36% and 40% just by adding variable speed drives to its aerators. This enables the aeration cells to control the amount of dissolved oxygen in each tank. The drive speeds up as the amount of oxygen drops and slows once the desired amount is reached, promoting greater energy efficiency at the source. For municipal budgets, this means a great deal for the bottom line as it successfully reduces operating and maintenance costs. This means more room for other much-needed infrastructure and facility upgrades to prepare for population growth and ensure economic success. Beyond the dollar value, there is a human element that incentivizes investments like Midland’s. Staff have greater insight into how their facility is performing, making them more engaged and confident in their decisions. Being able to show the impact of the facility in real time means that operators can swiftly make changes and monitor the impact they have, while they’re happening. This data can also be used as a reference by future operators. There is little reason for municipalities not to jump on the opportunity for digital transformation, making way for more productivity, efficiency, cost savings and sustainability. In fact, it is vital for the future prosperity of Canadian communities that they do.
ity into water systems lets operational and maintenance teams keep tabs on how the facility is operating, so they can stay ahead of any potential issues. Midland’s operations team can now proactively address any red flags, avoiding the financial, health and logistical consequences that come with unexpected downtime. When discussing budgets as they relate to city management, the ability to monitor the usage and cost of things like electricity is an effective way to identify areas that need adjusting. Such upgrades will enable municipalities like Midland to improve overall energy usage and cut costs. In fact, proper energy management can reduce electrical consumption by at least 30%, lowering maintenance costs at the same Steve McDowell is with Schneider time with minimal capex investment. Electric Canada. For more information, Operational elements of old plants visit: www.se.com/ca/en are often dated, consuming more energy than necessary. The motors, pumps and aerators installed years ago are not optimized to be as efficient as possible, especially during high-demand periods. These dated elements consume an overwhelming amount of energy and are often responsible for an average of 60% of electric energy usage in industrial settings. For context, the energy cost for a typical pump sits at roughly 40%.
Environmental Science & Engineering Magazine
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WATER
The presence of a CEC, such as a pharmaceutical in surface or drinking water can raise public concerns. Credit: kimberlyboyles, stock.adobe.com
Managing constituents of emerging concern
C
onstituents of emerging concern (CECs) include a variety of substances such as medicines, personal care products, flame retardants, hormones, algal toxins, and many others that are known to occur in water. Tens of thousands of chemicals are produced annually and used in a variety of industrial, agricultural, commercial, and household products. New substances or metabolites of existing chemicals are continually developed or discovered, and information regarding their toxicity, fate and transport is evolving. The fate and effects of chemicals on aquatic biota and human health are characterized for only a fraction of the chemicals in use and in the environment. Some CECs have been used for many years, but most have only been measured recently due to the advancement of sensitive analytical methods that allow detection of very low concentrations of compounds. For the thousands of unregulated CECs, often less is known about their environmental fate and potential effects on aquatic life and/or human health than regulated compounds. These CECs may have existed in treated wastewater, surface water, recycled water, groundwater, or drinking water for some 14 | October 2021
term resilience and reliability, meeting both community and ecosystem needs. The brief is presented in seven chapters. Chapter 1 introduces the issue of known and unknown CECs and how the One Water concept can be used to better evaluate risk associated with them. Chapter 2 describes potential sources and routes of CEC exposure to people and aquatic life, and highlights interconnections between water sectors. An overview of CEC issues is provided for freshwater surface waters, coastal and marine waters, treated wastewater, drinking water and potable water reuse, agricultural stormwater, and urban stormwater. Chapter 3 provides a generalized framework for categorizing the relative risks of CECs either singly or as mixtures to aquatic biota or people. An expanded discussion of human health and ecological risks is included with examples such as PFAS, algal toxins, pharmaceuticals, and 1,4-dioxane. Chapter 4 includes a discussion of key factors that limit the current understanding of CEC risks to aquatic life and people. This includes an overview of limitations of existing regulations and information, data gaps for individual chemicals, mixtures and co-occurring compounds, effects of non-chemical stressors, and uncertainties related to adverse effects. Chapter 5 discusses approaches, tools and examples related to weight of evidence, human health risk, and aquatic life risk. Chapter 6 highlights data gaps and active areas of research, including linking CECs to population-level effects in freshwater and marine systems; effects of CEC mixtures on aquatic life and human health; relative source contribution approach for certain types of CECs to help inform the assessment of CEC risks, especially to people. It also describes a decision support system that helps utilities screen for, and communicate about, CEC risks at their sites. Chapter 7 contains a list of resources relating to CECs in drinking water and water reuse, wastewater, water quality standards and criteria, and risk assessment.
time, but were only recently identified as potential concerns. The presence of a CEC, such as a pharmaceutical or industrial compound, in surface or drinking water can raise public concerns as to whether the water is safe to use for drinking, recreation, fishing, or other purposes. Detection of a constituent does not automatically indicate that humans or aquatic animals are routinely exposed to enough of a chemical to cause biological harm. The dose and frequency of exposure of a chemical or chemicals are important for interpreting possible risk to ecological and human health. Detection of CECs alone provides insufficient information without knowing the bioavailability and toxicological properties of the CECs. Information in Brief 5036 from the Water Research Foundation is designed to help utilities develop management and communication strategies related to CEC risks. The known risks and data gaps associated with CECs are addressed for multiple water sectors using the One Water concept. One Water is an integrated planning and implementation concept to For more information on WRF Brief managing finite water resources for long- 5036, visit: www.waterrf.org
Environmental Science & Engineering Magazine
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BIOGAS
Quebec landfill gas to be used as a renewable energy source
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aga Energy, a European company in the landfill gas-to-renewable natural gas (RNG) field, has signed a contract with Enercycle to deploy its patented WAGABOX technology at the Saint-Étiennedes-Grés landfill. The RNG produced will be purchased by Énergir, the largest natural gas distribution company in Quebec, and injected into its gas grid on-site. This project will be the first of its kind in Canada. Waga Energy will purchase the gas produced by the Saint-Étienne-des-Grès landfill for 20 years. A WAGABOX unit will be built at the site and will transform the gas captured at the landfill into a grid-compliant renewable natural gas. Designed to process 3,400 cubic metres of landfill gas per hour, it will produce 468,000 gigajoules of renewable gas per year, which corresponds to the annual consumption of 8,000 local households. Until now, landfill gas at Saint-Étienne-des-Grès site was captured and burned in a flare. To fund the initiative, Waga Energy is involved in financing the WAGABOX unit’s construction and operation, as well as the costs of connecting the site to the Énergir gas grid. Most of the unit will be built by a local company under the supervision of Waga Energy’s Canadian subsidiary. The cryogenic distillation module will be imported directly from France. The entire project is slated to be completed by 2022.
®
CLEAN, LOCAL AND RENEWABLE ENERGY The new RNG injection project is expected to improve Quebec’s environmental record. Through the substitution of renewable gas for fossil natural gas, the solution is expected to prevent the release of 23,000 tons of CO per year into the atmosphere. And, it will contribute to the Quebec government’s objective of introducing a 10% share of 16 | October 2021
Waga Energy now operates 10 units in France and five more units are under construction in France, Spain and now Canada.
renewable gas into the network by 2030. As Saint-Étienne-des-Grès is the largest community-managed landfill site in the province of Quebec, Enercycle will become the first North American waste treatment operator to benefit from the new technology. At present, the landfill site receives about 180,000 tons of waste each year. "This contract is the result of an initiative undertaken to identify the best technology to enable them to use our landfill gas to its full potential,” said Michel Angers, president of Enercycle. “Because of it, treating the gas will no longer be considered an expense, but rather a new income stream for us.” According to Angers, the landfill gas-to-renewable gas project represents “another step towards a more sustainable approach to landfill management”, as it “fits perfectly with the government’s greenhouse gas reduction objectives.” "The development of the green gas industry in Quebec is one of the cornerstones of our efforts to decarbonize our economy”, says Renault Lortie, vice-presi-
dent, customers and gas supply, of Énergir. LANDFILL GAS UPGRADING IS A REAL CHALLENGE Upgrading landfill gas into grid-compliant renewable natural gas can be difficult and complicated. Fundamentally, landfill gas is a complex mix of different gases created spontaneously by the action of microorganisms within the landfill. It is made up of methane, carbon dioxide, nitrogen, oxygen and other gases. Methane levels can jump from 35% to 55% on the same day due to weather conditions. HOW CAN WE OBTAIN RNG? Methane molecules must be separated from the other compounds to obtain renewable natural gas. The process is difficult, as the mixture of methane and oxygen can be explosive in certain proportions. Also, nitrogen, oxygen and methane are molecules of similar sizes and are extremely difficult to separate by filtration. continued overleaf…
Environmental Science & Engineering Magazine
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BIOGAS pipe is connected to an injection station operated by the local gas grid operator. Once commissioned, the unit injects RNG 24/7, with uptime in excess of 95%. It is fully automated, and remotely monitored through a command-and-control system. The first WAGABOX unit was commissioned in France in early 2017. Waga Energy now operates 10 units in France and five more units are under construction in France, Spain, and now Canada. ENERGY RECOVERY AND CIRCULAR ECONOMY Waste management is a major source of greenhouse gas emissions. According to the World Bank, it accounts for 5% of global emissions. Landfill gas represents a potential source of GHG emissions as it contains methane, a much more powerful greenWAGABOX’s technology combines membrane filtration and cryogenic distillation. house gas than carbon dioxide. Methane emission reductions have been found WHAT IS WAGABOX TECHNOLOGY? methane from the oxygen and nitrogen. particularly effective at mitigating global WAGABOX’s technology recovers The technology allows for RNG pro- warming in the near term. landfill gas in the form of grid-compli- duction that is pure enough to be directly Waga Energy is hoping to commisant RNG. It is the result of 10 years of injected into gas networks. Moreover, it sion 100 WAGABOX units worldwide research and development by Air Liq- helps landfill operators to optimize gas by 2025, which should enable them to uide and Waga Energy, and combines capture and contributes to reducing odour have a significant, global impact on climembrane filtration and cryogenic distil- nuisances and greenhouse gas emissions. mate change. lation. First, membrane filtration is used Logistically, the unit can be plugged to remove the carbon dioxide and impu- into any landfill gas collection network, For more information, contact Nicolas rities from the landfill gas. The gas is replacing a flare or a combined heat Noël, Waga Energy Canada. Email: then cryogenically cooled to separate the and power (CHP) engine. The exit-end nicolas.noel@waga-energy.com
18 | October 2021
Environmental Science & Engineering Magazine
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WATER INFRASTRUCTURE C-Factor program and procedure, starting with the assessment of five watermain sections with different pipeline materials,” said Danny Locco, superintendent water distribution and overall responsible operator for Hamilton Water.
Tuberculation on the pipe sampled from the flushing pilot.
Hamilton restores aging watermain sections following friction loss testing By Dave Alberton and Erika Waite
T
he City of Hamilton, Ontario, has one of the oldest and most complex water systems in Canada, with over 2,121 km of watermain serving a dispersed population of 550,000. A large portion (25.73%) of the watermains are unlined cast iron pipe (CIP). While the average age of Hamilton’s watermains are around 44 years, much of this CIP is closer to 83 years old. This is problematic because CIP is prone to corrosion and tuberculation, which accelerates over time. Tuberculation occurs when iron and manganese bacteria metabolize in water, resulting in oxidization and buildup of sediment and particulate matter on the inner wall of the pipe. Over time, this buildup can cause rusty water discolouration and mild odour, and in the worst case, it can affect the water quality. As corrosion builds up it reduces the internal diameter of the pipeline, leading to low flow rates, which is cause 20 | October 2021
for concern in providing sufficient water to residents and maintaining fire flow. In some cases, where a 150-mm pipe is reduced to 100 mm, the flow rate cannot support the addition of a new development or intensification. It also takes longer to pump water to the far end of the distribution network through pipes that have tuberculation, so energy costs are higher. As a member of the Corporate Climate Change Task Force, and one of the largest energy users in the city, Hamilton Water is looking for ways to reduce energy consumption wherever possible. During a unidirectional flushing pilot project, Hamilton Water operators experienced difficulties reaching flushing velocity required to scour the watermain. A section of pipe was removed, and severe tuberculation was discovered. “Based on this discovery and other indicators, like aging pipes, lowering flows and high energy costs, we developed a
CALCULATING THE C-FACTOR C-factor testing is a quick, minimally invasive way of determining the actual flow rate, pressure, and friction loss through the pipeline system. There are several formulas in hydraulics to do this, but one of those most commonly used in engineering practice is the Hazen-Williams equation. This equation relates the empirical relationship of the flow of water in a pipe with the physical properties of the pipe and the pressure drop caused by friction. The frictional resistance to flow causes energy loss in the system. This energy loss is a continuous pressure drop along the path of flow. The friction loss for each pipe section is estimated using the Hazen-Williams formula. The C-Factor represents the coefficient of friction of the pipe which determines the frictional resistance applied to the flow. Increased internal surface roughness (lower C-Factor value) reduces pipeline efficiency. A new pipe has a C-Factor value of 130-140 and a fair to normal interior has a value of 100. A significant reduction in pipe capacity is around 70 and a severe problem where the interior of the pipe is greatly reduced would be a C-Factor of 30-50. It is recommended that pipe cleaning and rehabilitation (i.e., relining) is done when the C-Factor is near or below 70. It takes two to three field staff to conduct each test section. This involves setting up and installing pre-set pressure loggers, closing the line-valves, and recording flow and system pressure at the hydrant. Once all the data is recorded in the loggers, it needs to be downloaded into a spreadsheet to calculate the C-Factor. The field testing took two days to complete and the results for the five tested watermain sections are summarized in Table 1.
Environmental Science & Engineering Magazine
Test ID
Subject Watermain
Tested Watermain Section
Location
Material
Diameter (mm)
Length (m)
Estimated C-Factor
Condition as Classified in AWWA M28
Test 1
Location 1
PVC
300
110
117
Fair to Like New Pipe
Test 2
Location 2
Cast Iron – Relined
150
206
100
Fair to Normal Pipe
Test 3
Location 3
Cast Iron
150
202
30
Severe Condition – Interior cross section greatly reduced
Test 4
Location 4
Ductile Iron
150
168
132
Like New Pipe
Test 5
Location 5
Concrete
400
187
126
Like New Pipe
Table 1. A summary of the C-Factor test results.
CLEANING THE INTERIOR PIPE WALLS Hamilton Water hired the consulting firm Jacobs, to do a unidirectional flushing pilot study in September 2017. Using a clean water source, this process creates high velocity flows and flushes from larger to smaller pipes, maintaining a minimum pressure of 20 psi over a dis-
tance no greater than 457 metres. Planning is vital to ensure controlled systemic and successful flushing. The pipe network needs to be isolated into single pipe sections for flushing sequences and the valves and hydrants need to be tested and exercised first, to ensure they can accommodate high-ve-
locity flushing. To remove sediment from the watermain, a flushing velocity within the range of 0.8 m/s to 1.5 m/s is needed. A flushing velocity greater than 2.1 m/s could result in permanent pipeline damage. Hydrants need to run until the continued overleaf…
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WATER INFRASTRUCTURE water is clear and free of debris. The final step is to complete a second C-Factor test to determine if the tuberculation was removed. If unidirectional flushing does not eliminate the tuberculation, then C-Factor testing results are passed to the City of Hamilton’s asset management section for review and to be put on the repair/replacement list. REPAIRING PIPE BY LINING Cured-in-place pipe lining (CIPP) is the best option for trenchless structural watermain rehabilitation. A bypass line is laid above ground for the duration of the cleaning and lining, so residents can still have access to water. There is also minimal excavation, keeping construction costs down to accessing and shoring of access pits. Once the pipeline has been scoured, a liner, composed of two woven polyester jackets impregnated with epoxy resin, is pulled downstream through the same access points used for the cleaning. It is then cured into place using pressurized hot water. As the resin cures, it forms a hard, tight-fitting, jointless, and corrosion-resistant replacement pipe. Individual liners can reach up to 150 metres. The new lining essentially creates a superpipe, by utilizing the strength of the existing watermain while restoring the pipe to its original diameter. This has an immediate effect on lowering operating costs by restoring flow rates and a return to optimal pumping efficiency. The end result is increased life of an existing asset and restoring flow levels and water quality back to new.
Graph showing the extension in pipe life from rehabilitation.
said Mike Zantingh, senior project manager of subsurface infrastructure programming – asset management. In 2000, Hamilton Water relined a section of CIP that was installed in 1930. A recent C-Factor test gave a reading of +150 which is the rating for a new pipe. However, another section of that pipe that was not lined, gave a C-Factor score of 34. This demonstrates the excellent results that can be achieved with rehabilitation. Replacement needs far more personnel and machinery and causes disruption to residents. Due to the cost and trenchless nature of rehabilitation, the City of Hamilton can fix more kilometres of its aging CIP watermains by lining versus replacing. As such, replacement is only considered as a last resort when the watermain requires an increase in capacity, or the road above it is being reconstructed due to pavement condiREPLACE VERSUS REHABILITATE tions. The end result of improved water quality and flow rates “The cost of replacing Hamilton’s watermains runs at around is the same. $1,200/m, versus lining which is about $800/m. Most waterSince the watermain rehabilitation program was initiated in mains are designed for 50-80 years of life expectancy, but with 2002, Hamilton Water has lined 80 km of watermain. The procleaning and lining we can get another 50 years out of them. gram is ongoing and continues to monitor and assess infraSo, the return on investment for rehabilitation is very good,” structure performance.
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Environmental Science & Engineering Magazine
Data is collated, first to determine risk of failure and the urgency of any required action, and then to assign a general risk assessment for prioritizing and planning works in coordination with other infrastructure needs. Once this is determined, asset forecasting and valuation is assessed so that the city can compile a strategic plan for funding approval and controlled annual spending. C-Factor testing also supports Hamilton’s development review and approvals process. Testing results are calibrated by computer modelling to verify adequate drinking water levels to service domestic demands and fire protection. Over time, an in-house inventory of C-Factor results will provide year-round access to key data at no cost to the devel- A flow hydrant used for C-Factor testing. It takes two to three field staff to conduct each test section. opment community. Zantingh concluded: “The ongoing program means we can consistently taining flow levels for firefighting and Dave Alberton and Erika Waite extend the life of existing infrastruc- adding new developments as the city are with Hamilton Water. Email: ture which will reduce energy costs and grows.” dave.alberton@hamilton.ca, improve water quality, while also mainerika.waite@hamilton.ca
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October 2021 | 23
WATER INFRASTRUCTURE
Field-testing now complete on mobile district metering project to cut water losses By Fabian Papa and Bradley Jenks
Mobile district metered area testing unit connected to water distribution system in Ottawa.
T
his is the final installment in a series of articles published in ES&E Magazine relating to the Ontario-wide leakage testing program using mobile district metered area testing. The article “Municipalities wanted for new water loss testing project” in ES&E’s April 2019 issue introduced the project. This was followed by “Mobile district metered area testing helps cut watermain leak losses” in ES&E’s February 2020 issue, which presented initial results. The field-testing component of the project is now complete. The results have been compiled and a final report will be available later this year. This article presents the key findings of the project and the resulting benchmarks that can be used by utilities as performance indicators. This project involved the develop24 | October 2021
ment and deployment of a mobile testing unit to directly measure the minimum night flow (MNF) into temporary and predominantly residential district metered areas (DMAs), which are relatively small, isolated sectors of a water distribution network. It also measured the pressure-leakage dependency of flow in the DMAs. Owing to the predictability of human behaviour and resulting water consumption patterns, the MNF is a reliable indicator of potential leakage and can help inform whether more efforts are needed to locate and repair meaningful leaks. The project involved a total of 20 DMAs across eight municipalities in Ontario and was a resounding success. Additional data, curated to the same standard as applied for this project, was provided from one of the municipalities that recently conducted a pilot DMA
study to help strengthen the benchmarking exercise. The article in the April 2019 issue of ES&E Magazine presented a case study from one of the early test sites where a leak of 4.4 L/s was discovered and repaired. Resulting savings were impressive: 139,000 m3 of annual water savings; $426,000 of annual financial savings; and 102 MWh in terms of annual energy savings. This singular result largely contributed to the project receiving the Professional Engineers Ontario – York Chapter’s 2020 Engineering Research Project of the Year Award and, in conjunction with York Region, the Ontario Water Works Association Water Efficiency Committee’s 2021 Award of Excellence (Public Sector). In total, three of the test sites exhibcontinued overleaf…
Environmental Science & Engineering Magazine
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WATER INFRASTRUCTURE ited excessive flows, suggesting high leakage or other forms of water (and energy) wastage, while the results from the other test sites were used to help establish the benchmarks representing “healthy” systems discussed below. For each of the DMAs, key information was obtained to help characterize the results, such as: • Energy consumption drivers, including the overall lift and distance from the source water to the DMA. • Demand drivers, such as the numbers of residential connections and units, population estimates and watermain lengths. • Historical average consumption data as well as land use information. For the most part, much of this information was readily available from the participating municipalities through their GIS and billing databases. To estimate DMA population, an algorithm (using Python) was developed to overlay the test area boundaries on 2016 census data, enabling the extraction of population data following appropriate filtering processes. This technique was applied with success and yielded the strongest correlation for benchmarking purposes. The plots shown in Figure 1 provide the benchmarking results for the (centralized) 60-minute moving average MNF value (MNF60) based on the residential unit count, the number of residential connections and the population. Each of the plots segregates the data between the “healthy” DMAs (in blue), “leaky” DMAs (in orange), and provides the derived benchmark values (broken grey lines) for each performance indicator. While correlations were also conducted for watermain length and the ratio of MNF60 to the average annual billed demand, these indicators were found to be somewhat less reliable than those offered in Figure 1. Additional discourse on these particular results will be presented in the final report, as well as the dissertation of one of the authors, both of which are available publicly on the project website. For practical purposes, it is often instructive and useful to consider several performance indicators when assessing the health of a particular DMA. For each of the test sites, the participating municipalities received a detailed test report which, in addition to presenting the DMA characteristics and field measurements, provided an economic evaluation to give a sense of the degree of investment that may be warranted based on the degree of leakage identified and the value thereof. Figure 2 provides a graphical representation of the annual value of excess leakage, as indicated by the size of each bubble. These are relative to the annual volume of the excess leakage and the marginal cost of water to the municipality for all sites with MNF rates exceeding the established benchmark value. The colour of the bubbles similar to the above represents “healthy” DMAs (in blue) and “leaky” DMAs (in orange). Unsurprisingly, the highest values of leakage occur when both the leakage amount and the cost of water are relatively high. This graphic illustrates the impact of the wide disparity in the marginal cost of water among the municipalities where testing occurred. The lowest costs occur for municipalities that draw and 26 | October 2021
Figure 1. Benchmarking results.
treat water from abundant surface sources. Conversely, the highest costs occur for municipalities that rely on purchasing imported water from neighbouring jurisdictions. Somewhat concerningly, the value of lost water for one of the “leaky” test sites is very low due to the low marginal cost of water for the municipality in question. This may lead to a lack continued overleaf…
Environmental Science & Engineering Magazine
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MUNICIPAL SYSTEMS
WATER INFRASTRUCTURE of financial motivation to actively seek and repair leaks. Raw financial costs alone, however, are not the only costs borne by society. In addition to the obvious waste of water that has been extracted from the natural environment and treated, it is also instructive to look at the energy implications of leakage. The largest part of water utility energy consumption is typically attributable to pumping. Figure 3 provides a similar graphical representation, although the results show a stronger correlation between the amount of leakage (x-axis) and the energy consumption (size of bubbles). This is due to the smaller disparity in the embedded energy in the water, which is a function of how high the water is lifted from the source, as well as the distance it needs to travel from the source to the customer. Of course, both the financial and energy implications are only components of an overall theme of responsible stewardship of both natural resources and infrastructure assets. One municipality contributed advanced metering infrastructure (AMI) data to the project, which assisted in further dissecting the basic components of the MNF, being legitimate consumption and leakage. Further deployment of AMI or similar technologies to record granular consumption data at hourly (or sub-hourly) frequencies allows for deeper analyses of consumption characteristics that can further improve estimates of excess leakage, lending an increasing degree of confidence in the results. That said, this project has demonstrated that there is often a clear distinction between generally “healthy” DMAs and those that are “leaky,” such that the latter represent the low hanging fruit which can be most affordably addressed for meaningful performance improvements. As these practices continue to evolve with municipalities and practitioners become increasingly proficient and sophisticated, the additional accuracy afforded from widespread DMA and AMI adoption can be expected to assist in identifying and dealing with smaller leaks, as well as the emergence of new leaks. With this project now complete and the concept of mobile DMA testing proven, the method is available for replication and commercialization. The benchmarking results can be used for any DMA configuration, whether temporary or permanent, utilizing the mobile unit or otherwise. The results obtained through this project can assist in providing an objective and reliable basis for assessing DMA performance and determining whether any deeper examinations (e.g., leak detection) or other interventions (e.g., pressure management) are worthwhile.
Figure 2. Value of excess leakage.
Figure 3. Energy wasted through leakage.
Council Industrial Research Assistance Program (NRC-IRAP) in addition to the participation of the Ontario Water Works Association (OWWA), the University of Toronto as well as the following municipalities: the Regions of Durham and York, the Cities of Greater Sudbury, Ottawa, Markham and Vaughan as well as the Towns of East Gwillimbury and Georgina.
Fabian Papa is with HydraTek & Associates (A Division of FP&P HydraTek Inc.) Email: f.papa@hydratek.com Bradley Jenks is pursuing a doctoral degree at Imperial College London. For more information, visit: www.hydratek.com/mobile_dma_testing The authors acknowledge the sponsorship of the Independent Electricity Services Operator (IESO) Conservation Fund (without which this project would not have been possible) as well as the financial assistance from the National Research 28 | October 2021
Environmental Science & Engineering Magazine
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STORMWATER
Combined sewer overflow discharges can be a direct conduit that allows raw, untreated sewage to enter the natural environment. Credit: aquatarkus, stock.adobe.com
The Detrimental Effects of Combined Sewer Overflows and COVID-19 By John Smythe
A
t wastewater treatment plants around the world, much emphasis has been placed on detecting COVID-19 in the raw sewage entering them. Researchers have found that even low levels of RNA from COVID-19, and other coronaviruses, can be detected in raw sewage before full- fledged outbreaks occur, thus allowing governments and health authorities more time to respond to protect public health and safety. Samples, and hence data, are being collected throughout sewage collection systems to further narrow down the areas of most concern in communities, areas that have high risk populations, senior’s residences and schools in particular. Laboratories are able to produce results in a matter of hours. The knowledge gained from these test results will allow health authorities to direct testing teams to these areas and utilize resources more effectively and reduce
30 | October 2021
waiting times for people getting tested. Test results can be the impetus to impose additional social and hygienic controls to further protect the general population. As with many undertakings of this magnitude, many off-shoot issues can arise that garner less attention. Such is the case with bacteria and viruses entering the natural environment via combined sewer overflow points, which includes organisms such as the COVID-19 coronavirus. Sewers in general have been in use for several hundred years and were originally designed to control flooding from precipitation events in populated areas. Water collecting on streets and roadways was conveniently whisked off and directed to the nearest low spot, usually a creek, river or lake. As communities began to grow, disposal of human sewage became a growing concern. Town designers eventually decided to dispose of sewage in
the same manner as they disposed of rainwater. Thus began the practice of directing human sewage to the rainwater sewers and hence to the nearest open body of water. It did not take long to realize that this practice had a negative effect on water quality, and fish and wildlife quickly began to suffer. As knowledge advanced, the relationship between human sewage and diseases such as dysentery, typhoid and cholera were better understood and prompted an outcry for wastewater treatment plants to be constructed to help control disease outbreaks in communities. Once treatment plants were constructed, pipes discharging to the lakes and ponds were redirected to the treatment plants. Treatment plants and sewer pipes were often sized and constructed based on the population at the time, without any foresight as to how quickly the population would increase. This often quickly rendered many plants woefully small for their purpose. They were primarily designed to treat human waste, but due to the “single sewer pipe” scenario, rainwater and snow melt water was also being sent to wastewater treatment plants. This is likely when the term “combined sewer” was coined. Due to their limited size, treatment plants could handle only so much flow and when heavy rain or melt events occurred, sewer pipes became filled to capacity and plants were overwhelmed, causing plant upsets and flooding at treatment facilities. To alleviate the excess flow going to the treatment plants under high flow conditions, pipes that connected to the ponds and lakes were reconnected near the top of treatment plant pipes. If treatment plant pipes became too full, this allowed the top portion of the pipes to flow to the natural environment again. Once the treatment plant pipe returned to a level below the overflow point, discharge to the environment ceased and the sewage continued to make its way to the treatment plant again. Each time the treatment plant pipe went over capacity, overflow to the natural environment repeated itself until the flow levelled off below the overflow point. This arrangement suited the needs
Environmental Science & Engineering Magazine
of the treatment plants, but nature was again taking a biological hit from overflow events. To this day there are still many overflow points in Canada that actively discharge to creeks, rivers and lakes when heavy rainfall or heavy snow melt events exceed the capacity of combined sewers. The discharges are a direct conduit that allow raw, untreated sewage to enter the natural environment. They are a veritable cocktail of chemical and biological contamination. Climate change only serves to amplify the effect on the natural environment. As the temperature of the planet increases, so does the intensity and frequency of extreme weather events. This in turn causes more frequent overflow events leading to more degradation of receiving waters. Climate change is also causing receiving water temperatures to increase, making for ideal bacteriological growing conditions. Along with extreme weather events, comes more debris in the sewers, which
can cause blockages that can cause overflows to continue, even under relatively dry conditions. As combined sewers age (some are over 200 years old) they deteriorate. They were often constructed with brick and mortar, which has broken down over time. Many combined sewers are currently flowing at near-capacity all the time, making inspection and repairs difficult and dangerous. Modern research has revealed that COVID-19 is a zoonotic pathogen that can be transmitted between animals and humans. As sewage overflows continue, plants, animals, birds and fish are being directly exposed to COVID-19, along with a host of other bacteriological and chemical hazards. The problem is easily addressed but comes with a high price tag. Simply put, combined sewers need to be removed and replaced with separate stormwater pipes that go to the natural environment and separate sanitary sewer pipes that send human waste to wastewater treat-
ment plants. This will have several benefits in that untreated sewage will no longer be directed to the natural environment and flows to the treatment plants will be reduced, thus lowering overall treatment costs. Many municipalities are making efforts to move in that direction but progress has been glacial at times. As economies fluctuate, projects are re-prioritized and replacement of combined sewers often falls off the ledger sheet. Until combined sewers are eliminated, our best course of action is diligent monitoring of combined sewer overflow points and immediate corrective action if a problem is identified. This will require a strong commitment on behalf of municipalities, provincial ministries and in many cases, the public at large. John Smythe is with NOVA Training and Development Inc. For more information, email: contact@nova-td.net, or visit: www.nova-td.net
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October 2021 | 31
STORMWATER
Home Flood Protection Program empowering homeowners to take action
A
Cities such as Burlington, Ontario, have seen an increase of severe storms in recent years. In August 2014, for instance, intense rain flooded about 3,500 basements in the community of just over 200,000 residents. Credit: Robert Kneschke, stock.adobe.com
Stormwater
s intense rainfall events continue to increase across Canada, more homeowners should be vigilant about reducing the risk of basement flooding, say University of Waterloo program experts. The university’s Intact Centre on Climate Adaptation (ICCA) developed a Home Flood Protection Program as a blueprint for taking action against basement flooding, a consequence that is costing homeowners an average of $43,000 per incident, according to records from the Insurance Bureau of Canada. The centre’s education program has already been successfully piloted in cities such as Toronto and Saskatoon, where homeowners utilized a threepronged strategy consisting of assess-
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32 | October 2021
Environmental Science & Engineering Magazine
ment services, outreach strategies, and tools and tips for taking action at various price points both outside and inside the home. “Reducing residential basement flood risk at a national scale is a complex challenge that will involve building on the successful work already underway by governments, not-for-profits, academia, retailers, and insurance companies to educate residents and provide financial incentives where possible, to help homeowners take sustained action to reduce flood risk,” states a program report authored by the ICCA’s Cheryl Evans and Dr. Blair Feltmate. Cities such as Burlington, Ontario, have seen an increase of severe storms in recent years. In August 2014, for instance, intense rain flooded about 3,500 basements in the community of just over 200,000 residents. Following the creation of the ICCA, city officials looked to engage its flooding experts and attempt a broad-based outreach to educate Burlington homeowners and offer flood-risk assessments. Similar efforts occurred within Toronto and Saskatoon in 2018. Part of the program’s intent is for homeowners to empower themselves and take action, some of which can be done without the help of a contractor. Some of the easiest options include removing debris from the nearest storm drain outside and floor drain inside; cleaning eavestroughs; extending downspouts; installing window wells and covers; and storing basement valuables in watertight containers. Additionally, some basic work that can be very effective yet requires some professional help, could be to correct the grading around the foundation, install and maintain a backwater valve and flood alarm, replace deteriorating pipes; or to test the sump pump and install backup power. When it comes to some of the top flood risks outside the home, the ICCA points to cracks or gaps in windows or frames; proper sump discharge; clogged drains; poor door seals; and belowgrade downspout discharge. During the pilot projects, the ICCA found that 82% of participating homes with window wells had wells that were www.esemag.com @ESEMAG
not 10 cm to 15 cm above the surface of the ground and sealed at the foundation. Inside the home, the pilot projects revealed that 85% of homes with sump pumps did not have a backup sump pump and 84% did not have backup power in case of a power outage. Additionally, when it came to homes endangering their furniture and electronics in a flood-risk zone, 71% of participating
assessment homes were taking that risk. During the program’s pilot periods, 60% of participants completed actions that cost under $500 and could be completed by a knowledgeable or “handy” homeowner generally within a day. Coordination of the flooding protection program has since moved from the university to private service providers.
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October 2021 | 33
WATER
During a physically-distanced, ground-breaking ceremony, key members of the Community Circle were gifted blankets and traditional medicine.
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hoosk’uz Dene Nation’s traditional territory is located in the upper Blackwater River watershed west of Quesnel and south of Vanderhoof in central British Columbia. The main residential community is approximately 200 kilometres west of Quesnel on Kluskus Lake. The Village of Kluskus is serviced by forestry roads, but year-round access is difficult and limited during winter and spring thaw. The community originally sourced its water from a single well adjacent to Kluskus Creek. This shallow well was susceptible to turbidity and bacterial contamination, such as Escherichia coli and total coliforms. Current community Wells 1 and 2 were drilled in 2008 and contained elevated levels of iron and manganese that do not meet the Canadian Drinking Water Quality Guidelines. In addition, the wells were close to the community’s septic field and traditional burial grounds, so many community members did not use water from them for drinking. As such, the Nation has had to supply bottled water for drinking, food preparation, and cooking to community members since the early 2000s. In 2015, Associated Engineering (AE) worked with the community to consider several surface water sources surrounding the village. Upon examination, the long-term sustainable yield of these surface water sources would not meet the domestic water demands of the community. This meant looking for alternative groundwater wells, based on site reconnaissance by hydrogeologists. “We worked with the Nation, Indigenous Services Canada, First Nations Health Authority, and the RESEAU Centre For Mobilizing Innovation to identify wells that were on the other Environmental Science & Engineering Magazine
side of the bridge, away from the community septic field and the traditional burial grounds," said project manager Freda Leong. The two new water supply wells, Wells 3 and 5, were drilled in 2017. Associated Engineering also served as the technical lead for other needed improvements to the existing domestic water system, from feasibility investigation through to construction. Major infrastructure upgrades included a new water treatment plant with ultraviolet and chlorine disinfection and a new transmission main from the plant to the existing water storage reservoir. The transmission main and all civil works were completed before the new packaged water treatment plant was delivered to the site in January 2021. The Truth and Reconciliation Commission of Canada: Calls to Action states: “Commit to meaningful consultation, building respectful relationships, and obtaining the free, prior, and informed consent of Indigenous peoples.”
AE’s commitment to this call to action was through the adoption of a Community Circle Approach for this project. This approach involved open dialogue and idea sharing with all members of the Community Circle. The aim was to encourage and facilitate full, honest, and respectful engagement with the Lhoosk’uz Dene Nation. Before the COVID-19 pandemic, AE held many in-person meetings and workshops with community members, Elders, and the Chief and Council. Leong said: “As a result of the pandemic, we held more virtual community meetings, but the pandemic has not stopped us from connecting.” There was a physically-distanced, ground-breaking ceremony before construction started. Key members of the Community Circle were gifted blankets and traditional medicine. Leong said: “This was such an honour for all of us. I carry my medicine bag with me everyday as protection and as a reminder of my connection to the community.”
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October 2021 | 35
PIPING
A new approach to construction allows for smaller valve vaults By Chris Sundberg and Wayne Biery
I
n water treatment and wastewater management facilities, one of the common structural components are valve vaults, which are a key element of conveyance systems. However, at a cost of about $10,000 per square metre, building them in the traditional way, using an M11 harness to restrain the pipe, is expensive. If the goal is to do things more efficiently, sustainably, and safely, it is important to examine how the M11 harness works and pinpoint its shortcomings. Valve vaults are confined spaces and must be built for functionality as well as worker safety. Because unrestrained piping is unstable, designers have become accustomed to using an M11 harness, often installed with external thrust blocks, to prevent movement. In some cases, the vault walls them-
36 | October 2021
The robust design of the Victaulic grooved couplings made them ideal for installation on 36-inch through 96-inch couplings on multiple valve vaults for the Hanlan Water Project in Ontario. Credit: Victaulic
selves have been designed to function as substitutes for thrust blocks, and in those cases, safe construction means designing thickened concrete walls that
can resist punching shear from transfer of piping thrust loads. The result is that the vaults are very large, which means constructing them
Environmental Science & Engineering Magazine
requires more excavation over a greater area, a process that takes significant time and costs a great deal of money. Safety is another critical consideration. Because valve vaults are enclosed, they must have adequate lighting, ventilation, and drainage to provide safe ingress-egress for operators and maintenance personnel. With the M11 harness, there are multiple areas that can fail, and when failures occur, they are costly. The question that must be addressed is: “How is it possible to economize space in valve vault construction in a way that is both safe and effective?” The answer is to provide efficient thrust restraint for the pressure piping that passes through the vault in a way that does not require a harness. Successful installations have proven it is possible to reduce the footprint of the valve vault by using grooved and shouldered couplings, components that have been used for decades in other applications to manage dynamic movement. Grooved couplings provide the necessary restraint, as well as the required flexibility to reduce the footprint of the valve vault within the vault interior and in the vault walls themselves. A typical grooved pipe joining method is simple and reliable. The four basic components are the grooved pipe, the coupling housings, the bolts and nuts, and the gasket. The coupling housings fully enclose the elastomer gasket and secure it in position for a proper seal, engaging around the full pipe circumference to create a unified joint. Bolts and nuts hold the housings together, and a synthetic elastomer gasket creates a triple seal effect on the pipe ends. A tension seal is created as the gasket is stretched around the pipe. A compression seal is created as the coupling housings press the gasket onto the pipe. Finally, the sealing lips of the gasket are forced down onto the pipe end when the system is energized. Together, these features create a leak-tight, self-restrained joint. When grooved couplings are used within the valve vault, they eliminate the need for dismantling joints. These joints are required with the M11 harness, which relies on tie rods that span the joint and are connected to a pair of rings www.esemag.com @ESEMAG
designed to transmit the loads from the rods into the pipe wall. Disassembling and dismantling joints requires that all the harness rods be un-threaded and drawn through holes in the rings in a direction parallel to the pipe wall. For the vault to accommodate dismantling, it must be twice as long as the tie rods, which significantly increases the valve vault footprint. Grooved couplings also can reduce the thickness of valve vault walls. By design, grooved couplings bear sufficient thrust to safely contend with the forces experienced in water treatment and wastewater management facilities. The couplings restrain the piping, internally eliminating the need for external anchor blocks (or walls) for stability. This also eliminates the associated cost of excavation and construction.
Grooved couplings provide the necessary thrust restraint for the pressure piping that passes through the vault in a way that does not require a harness, safely reducing the footprint of the vault as well as the required thickness of the vault walls. Credit: Victaulic
Chris Sundberg and Wayne Biery are with Victaulic. Email: chris.sundberg@victaulic.com, or wayne.biery@victaulic.com
October 2021 | 37
SPILLS & CONTAINMENT
Microbes biodegrade diesel fuel in Labrador Sea, study finds
M
arine bacteria in the frigid waters of the Labrador Sea may be capable of biodegrading fossil fuels following diesel or crude oil spills from steadily increasing shipping traffic, a new study suggests. The study, published in Applied and Environmental Microbiology, a journal of the American Society for Microbiology, found that providing additional nutrients, known as nutrient biostimulation, can enhance hydrocarbon biodegradation under low temperature conditions. The research team recreated oil spill remediations inside bottles by combining mud from the top few centimetres of seabed with artificial seawater. Then, they added different nutrient amendments such as nitrogen and phosphorus at different concentrations to hydrocarbons extracted from diesel and crude oil-amended microcosms that had been frozen at -20°C after a 71-day incubation period. The Labrador coast experiments were performed over several weeks at 4°C to approximate the temperature in the Labrador Sea. “Our simulations demonstrated that naturally occurring oil-degrading bac-
teria in the ocean represent nature’s first responders to an oil spill,” announced study co-author Casey Hubert, associate professor of geomicrobiology at the University of Calgary. Hubert worked for the past several years as a scientist at the Max Planck Institute for Marine Microbiology in Germany. The study, which is the first of its kind, indicates that benthic microbial communities are important because only a fraction of spilled oil typically sinks so that its biodegradation occurs at the seafloor. Biostimulation with nitrogen and phosphorus was shown to be effective at enhancing alkane and polycyclic aromatic hydrocarbon degradation following low concentration (0.1% volume per volume) diesel and crude oil amendments. At higher concentrations (1% volume per volume) only alkanes in diesel were consumed, “suggesting toxicity induced by compounds in unrefined crude oil,” the research states. “Biostimulation allowed for a more rapid turnover in the microbial community in response to petroleum amendments, more than doubling the rates of CO2 increase during the first few weeks of incubation,” the study found.
Stock image of an oil sheen on water. The Labrador coast experiments were performed over several weeks at 4°C to approximate the temperature in the Labrador Sea. Credit: Michal, stock.adobe.com
The study also suggests there is a growing demand for microbial biodiversity evaluations given the pronounced impact of climate change in the Labrador region. One of the largest oil spills in the region occurred in 2018 during a fierce winter storm, when an estimated 250,000 litres of oil spilled from Husky Energy’s SeaRose platform, about 350 kilometres from St. John’s. “The behaviour and fate of spilled oil in the Labrador Sea, however, remains difficult to predict on account of accessibility to the area, cold ocean temperature, and prolific sea ice,” the study states. “A better understanding of oil spill dynamics in this region and other sub-arctic areas should help in managing future oil releases in these vulnerable environments.”
Celebrating 75 years of Engineering Excellence
Associated Engineering is celebrating our 75th anniversary! We are very proud of our long history as an employee-owned, Canadian consulting firm. Our approach is to collaborate with our clients to create sustainable and resilient solutions that shape a better future for all of us.
www.ae.ca
38 | October 2021
Environmental Science & Engineering Magazine
WATER
Algal bloom toxicity harming fish year round, U of G study finds
C
yanobacterial toxins can harm fish populations even in the early stages of algal bloom development when humans cannot see it, not just during the peak of summer, new research from the University of Guelph has found. “The data suggests we need to be tracking these blooms as early as spring,” announced post-doctoral researcher Dr. René Sahba Shahmohamadloo from the University of Guelph’s Department of Integrative Biology. Shahmohamadloo led the study along with researchers from the Ontario Ministry of the Environment, Conservation and Parks. The work was recently published in Environmental Science & Technology. The research team examined the negative impacts of algal blooms before the
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release of cyanotoxins, microcystins in particular, which are the most common toxin released by blooms. Adult and juvenile rainbow trout were exposed to two types of microcystin toxicity, intracellular and extracellular. Within 24 hours after exposure, the fish had buildups of the toxin in most tissues, with greater accumulation in the extracellular state, the study says. Within 96 hours, adverse health effects were measurable in all tissues and cancer-causing proteins were detected. “We saw at the cellular level that cyanotoxins are causing these adverse health effects in fish,” said Shahmohamadloo in a statement from the University of Guelph. “The implications for that are substantial for governmental and non-governmental regulatory agen-
Research apparatus in Aquatic Toxicology Unit of the Ministry of the Environment, Conservation and Parks. Credit: University of Guelph and the Ontario Ministry of the Environment, Conservation and Parks
cies that are trying to protect the public and also fisheries,” he added. The toxicity exposure may not kill fish, the research team found, but noted that the health effects may be long-lasting.
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October 2021 | 39
WASTEWATER
Improving ammonia removal at a petrochemical plant’s lagoon
A
petrochemical manufacturing plant in Western Canada was experiencing difficulty in meeting the required ammonia discharge limit from its on-site wastewater lagoon system during cold-weather conditions. The three-cell lagoon system provides pretreatment of the facility’s sanitary and process wastewater before the effluent is released to the municipal sewer. But during the winter months, the system struggled to achieve the discharge limit set. Low temperature and high BOD are often responsible for impeding the ability of a wastewater lagoon to remove ammonia and can result in non-compliance. Unfortunately, the problem was compounded when operators learned that more stringent discharge regulations were coming. Operators took proactive steps to install aeration/mixing and baffle curtains in the third pond in an attempt to improve performance, but these measures did not achieve the anticipated results. As such, the petrochemical plant
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needed a simple, cost-effective way to reliably achieve high ammonia removal in winter conditions. A Bishop BioCord Reactor pilot system was installed in 2018 to evaluate its ability to improve BOD and ammonia removal in Pond 2 of the facility. These reactors dramatically increase biological nutrient removal and require little energy or operator oversight. The containerized plug-and-play system arrived fully assembled and was quickly installed with only four connections for influent, effluent, overflow and power. Effluent from Pond 1 was directed to a 3,400 L Biocord tank in the sidestream system. Both Pond 2 and the
THE RESULTS Throughout the 14-week pilot test, the BioCord system in Pond 1 performed significantly better than Pond 2 for reducing ammonia concentrations and other key treatment parameters such as cBOD, TSS and COD. Even when the temperature of the wastewater fell to as low as 2.8°C, BioCord was able to remove 97% of the
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BioCord system received the same influent for the duration of the pilot test. After about six weeks of operation, a second 3,400 L tank, was added to the pilot system to cope with higher than anticipated organic loading.
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ammonia. On average, the pilot system was able to reduce ammonia concentration in treated effluent to about 13 mg/L, from an influent concentration of about 38 mg/L. By comparison, Pond 2 was only able to achieve an average of 2% ammonia reduction during cold conditions, reducing the concentration from an average of 38 mg/L to 37 mg/L. This was well above the site’s regulated discharge limit of 30 mg/L. Similarly, the BioCord Reactors significantly reduced cBOD from influent levels that were nearly as high as 75 mg/L to less than 10 mg/L in treated effluent. Achieving sufficient cBOD removal is an important first step in ammonia reduction since BOD-reducing bacteria and nitrifiers both require oxygen to thrive and treat wastewater.
A Bishop BioCord Reactor pilot system was installed in 2018 to evaluate its ability to improve BOD and ammonia removal in Pond 2 of the facility.
gy-intensive blowers, a full-scale BioCord system is installed directly into the treatment lagoon, helping to minimize capital costs and eliminating the need to expand plant footprint. This design, along with low-energy KEEPING COSTS LOW AND AVOIDING compressors, rather than costly blowFOOTPRINT EXPANSION ers enables the system to consume about Unlike alternative approaches that 50% less energy. The compressors, commay require additional tanks and ener- bined with an integrated aeration dif-
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October 2021 | 41
GROUNDWATER
Aquifer recharge rates can affect landfill leachate plume migration rates By Paul F. Hudak
M
unicipal landfills are a common source of groundwater contamination in towns and cities worldwide. While unlined older ones can frequently contaminate groundwater, leachate can also pass through small holes or tears in liners beneath modern landfills. Installation and maintenance costs, as well as time frame, are important considerations for addressing contaminated groundwater. Management approaches using little energy have become popular over the past two decades. Examples include downgradient wells or trenches filled with reactive media, which can remove some but not all of the numerous contaminants typically found in landfill leachate (USGS, 1999; Gavaskar, 1999). Excavation and maintenance costs, along with limited depth potential, greatly restrict the use of trenches in practice. Vertical or slanted passive wells can reach greater depths (Divine et al., 2018), but have small capture zones and short contact times with contaminants (Hudak, 2013). Alternatively, monitored natural attenuation may be a viable management option in some settings, particularly for narrow plumes emerging from small holes in plastic liners (Lee and Jones-Lee, 1994). Attenuation involves all processes that naturally decrease contaminant concentrations, including biological and chemical processes, as well as dilution and hydrodynamic dispersion. Previous work demonstrates a capability for managing contaminant plumes with the source removed, or no longer leaking. However, leachate releases at the bottom of waste impoundments are difficult to control and may be active for years, suggesting the need for ongoing management of associated plumes in groundwater. This study examined the effect of recharge to the water table as a compo42 | October 2021
While unlined older landfills can frequently contaminate groundwater, leachate can also pass through small holes or tears in modern landfill liners. Credit: Lost_in_the_Midwest, stock.adobe.com
nent of natural attenuation for stabiliz- crossed the northern, southern, or boting narrow contaminant plumes from tom edges of the model. continuously leaking sources. Both homogeneous and heterogeneous hydraulic conductivity fields were METHODS input to the model in alternate simuMT3DMS (Zheng and Wang, 1999) lations. In homogeneous simulations, was used to simulate groundwater flow hydraulic conductivity was 0.5 m/day. and mass transport in an unconfined For heterogeneous simulations, a ranaquifer beneath a hypothetical, lined dom hydraulic conductivity matrix was waste impoundment. In this applica- obtained from a distribution (log10, m/ tion, the finite-difference grid consisted day) with a mean of -0.301 and standard of 150,000 cells, with 300 rows oriented deviation of 0.18. east-west and 500 columns trending The correlation length of hydraunorth-south. lic conductivity in the random matrix Nodes in cell centres were 0.15 m equaled two metres. Other model apart along rows and columns. Hydrau- parameters were representative of allulic head was a constant 5.0000 m and vium documented in the literature: effec4.2515 m at the westernmost and east- tive porosity = 0.25, longitudinal disperernmost columns of nodes, respec- sivity = 1.0 m, transverse dispersivity = tively. Head values were measured from 0.1 m, and effective molecular diffusion a datum of 0 m at the bottom of the coefficient = 0.00001 m2/day (API, 1989; model. The hydraulic gradient averaged Gelhar et al., 1992; Fetter, 1994). 0.01 eastward across the model. No flow A random number generator identiEnvironmental Science & Engineering Magazine
fied five leak locations in the footprint of the landfill. For each release, the model produced contaminant plumes for the homogeneous and heterogeneous hydraulic conductivity fields. Leakage rates were 0.1 m/day with a concentration of 100 mg/L. No leakage or recharge occurred over the remainder of the landfill’s footprint. Outside the landfill, the recharge rate equaled 0 m/day, 0.0003 m/day, or 0.0005 m/day in alternate scenarios. Contaminant plumes had a boundary value of 1.0 mg/L. Model output showed the evolution of simulated contaminant plumes through time as they approached a boundary located 32 m downgradient of the landfill. The preconditioned and generalized conjugate gradient solvers were used in groundwater flow and mass transport simulations, respectively (Zheng and Wang, 1999). Mass balance errors were less than 0.1%. RESULTS With no recharge outside the landfill, contaminant plumes continued to grow and eventually reached the downgradient model boundary in both homogeneous and heterogeneous aquifers. The heterogeneous hydraulic conductivity field rendered a more complex flow pattern; thus, contaminant plumes showed more variability in shape. Maximum concentrations were 15.2 mg/L in the homogeneous aquifer and 10.8 to 16.9 mg/L in the heterogeneous aquifer. The amount of time for contaminant plumes to reach the downgradient model boundary ranged from 2,420 to 2,870 days in the homogeneous aquifer and 2,430 to 2,890 days in the heterogeneous aquifer. In the homogeneous aquifer, both recharge rates outside the landfill, 0.0003 m/day and 0.0005 m/day, led to contaminant plumes that stopped growing (stabilized) before reaching the downgradient boundary. However, the higher recharge rate resulted in a shorter distance of contaminant travel away from the landfill. Similar results were observed for the heterogeneous aquifer. In both the homogeneous and heterogeneous aquifers, contaminant plumes stabilized after www.esemag.com @ESEMAG
approximately 10 years. The results outlined above suggest that monitored natural attenuation, aided by recharge to the water table, may be an effective alternative for managing small contaminant plumes from continuously leaking sources in some homogeneous and heterogeneous settings. An average recharge rate was used in this study, whereas in practice, recharge to the water table would likely vary over time. Variable recharge would lead to pulsing contaminant plumes achieving quasi-stability, growing during drought and shrinking with dilution during recharge. Additionally, this study was conservative in that sorption and biochemical reactions were not simulated as part of the attenuation process. In many settings, such processes would further contribute to stabilizing contaminant plumes. Site-specific conditions should strongly influence management protocols used in practice. For example, fast-moving groundwater, nearby properties or supply wells, and large contam-
inant plumes would likely require alternative approaches. CONCLUSION This study examined the effect of recharge rate on attenuation of leachate plumes originating from small continuously leaking sources in simulated homogeneous and heterogeneous aquifers. For the parameters examined here, natural attenuation aided by recharge to the water table effectively stabilized some contaminant plumes before reaching the downgradient model boundary. Increased recharge resulted in a shorter distance of contaminant travel. Natural attenuation aided by recharge, with careful monitoring, may be a viable management option in some settings. Paul F. Hudak is with the Department of Geography and the Environment at the University of North Texas. Email: hudak@unt.edu References available upon request.
October 2021 | 43
WATER
Geomembrane solves waterproofing challenge in difficult underground installation By Felon Wilson
T
he refined version of potash, an essential crop nutrient, contains a concentrated amount of soluble potassium chloride (KCl), readily absorbed by plants. Potassium, nitrogen and phosphorus are the most essential crop nutrients and are in high demand for agricultural operations worldwide. Potash is found underground in ancient seabeds that evaporated millions of years ago. Saskatchewan is blessed with some of the purest deposits in the world, found 1,000 metres to Figure 1: The waterproofing solution consisted of a geomembrane that was terminated along the 3,000 metres below ground. circumference of the work area wall. The province is the largest producer of potash in the world and has extensive reserves. ash mine needed a waterproofing mem- shaft that is used to transport personRecently, a large Saskatchewan pot- brane during maintenance on a service nel and equipment from ground-level to various depths of the mining operation. The site alone posed a number of challenges. It was 1,300 metres below grade and shaft wash water was expected to be entering the area long term, causing erosion problems. Additionally, salts were likely to be present, raising corrosion and compatibility concerns for any activity in the area. Faced with these conditions, the mine engineers turned to Green Earth Environmental and Seaman Corporation’s XR-5 Geomembrane for a solution. Site conditions can be generally summarized as an approximate 10 m diameter earthen shaft, in a bored hole. Inside the bored hole was a steel service shaft. Additionally, there existed an access ramp that led from the service shaft to active mining areas and other limited open areas for maintenance access. Site conditions were tight for any type of construction. The interior walls of the bored hole were composed of soft rock that made anchoring of a waterproofing geomembrane difficult. Conventional expanded anchors, as used for geomembrane batten anchors, were not reliable and a deeper anchoring was required. In some areas, a concrete block retain-
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44 | October 2021
Environmental Science & Engineering Magazine
ing wall was needed both for anchor and wall stability. EPS geofoam was employed to provide stability between the shaft opening and a bench around the shaft. The access ramp entered laterally through the maintenance area into the shaft and was above the bench. Again, site conditions were tight and complex. The ultimate waterproofing solution is illustrated in Figure 1. It consisted of a geomembrane that was terminated along the circumference of the work area wall, outside of the bore shaft, either into the wall or into a constructed retaining wall. The geomembrane covers the bench area between the interior wall and the borehole, then drapes over the geofoam, forming the edge of the borehole. Overall width of the geomembrane varied greatly from 2.5 m to 16 m, due to the irregularity of the maintenance area and the borehole itself. Geofoam was installed along the open edge of the bore shaft to stabilize that edge against erosion. The geomembrane was to keep water away from the geofoam and the edge of the borehole to prevent further erosion between the borehole and the steel liner of the shaft. The access ramp was above the bench at varying levels in the maintenance site, requiring even tighter working conditions. Green Earth Environmental employed prefabricated panels where possible, min- Felon Wilson is a consultant with imizing handling and welding. Seaman Corporation.
For more information, visit: www.xrgeomembranes.com or www.greenearthenvironmental.ca
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WATER
Integrating biofiltration into existing water plants to improve contaminant removal
B
iofiltration is a well-established operational practice in water treatment plants that can remove multiple contaminants, including total organic carbon (TOC), taste and odour (T&O), disinfection byproduct (DBP) formation potential (FP), regrowth potential, ammonia, iron, manganese, and algal toxins. When ozonation is practiced upstream of biofiltration, the combination further enhances TOC and T&O removal, and reduces DBP formation and microbial regrowth in the distribution system. Considerable research has been conducted to advance the science and engineering of surface water biofiltration over the last decade. This includes a Water Research Foundation project (WRF 4731), which assessed various biofiltration performance optimization strategies, including nutrient supplementation, substrate supplementation, pH adjustment, pre-oxidation and chlorine, or some combination of these strategies. This tailored collaboration project with the City of Columbus, Ohio, aimed to combine much of the biofiltration research and demonstrate extensive fullscale biofiltration optimization and integration into the overall treatment train. Optimization and integration testing were conducted at the city’s Dublin Road Water Plant (DRWP) and Hap Cremean Water Plant (HCWP). Both are conventional two-stage drinking water plants with treatment trains consisting of coagulation, softening, ozone/biofiltration (O3/BAF), and chlorine disinfection. The filters at both plants have dual media beds (GAC/sand). Production capacities are 450 and 300 million litres per day at DRWP and HCWP, respectively. The O3/BAF is primarily used for removing DBP precursors. Proformance, an automated data management tool developed as an Excelbased tool during WRF project 4525 was upgraded to an MS Access platform, tailored for this project, and used for managing, analyzing, and interpreting test results. 46 | October 2021
Considerable research has been conducted to advance the science and engineering of surface water biofiltration over the last decade. Credit: nattapon, stock.adobe.com
OBJECTIVES AND HYPOTHESES The overall objective of this project was to perform a holistic optimization of the biofiltration process at DRWP and HCWP, in order to enhance biofilter performance, and understand how the biofiltration step can be most efficiently integrated with upstream processes without compromising finished water quality. To meet these objectives, four hypotheses were developed when designing the biofiltration and upstream process optimization tests. Phosphorus supplementation – Based on historical water quality data, phosphorus supplementation might improve biofilter performance. Pre-chlorination – Pre-chlorination with low residual free chlorine (~0.25 mg/L Cl) would improve biofilter hydraulics without affecting TOC removal. Biofilter shutdown – Appropriate selection of a biofilter maintenance strategy would minimize negative impacts of short-term (72-hour) and long-term (two-week) shutdowns. Upstream process optimization – Economic benefits could be realized by
optimizing upstream coagulation and ozonation, targeting partial TOC transfer to the optimized biofilters without compromising overall plant performance. PHOSPHORUS SUPPLEMENTATION Historical data showed a bioavailable C:N:P ratio of 293:31:1, suggesting that the biofilter influent was phosphorus limited and that supplementing phosphorus might improve biofilter performance. Since the historical data set was incomplete, baseline biofilter performance was monitored and characterized without the addition of phosphorus from March 3 through June 4, 2018, at DRWP, and March 3 through June 29 at HCWP. Phosphorus supplementation was evaluated at DRWP and HCWP from June 4, 2018 through January 29, 2019, and June 29, 2018 through November 13, 2018, respectively, targeting 50 to 450 μg/L phosphorus as P in the test biofilter influent. The plant at HCWP was completely shut down from November 13, 2018 through February 3, 2019, for construction work associated with UV disin-
Environmental Science & Engineering Magazine
fection installation downstream of the biofilters. Hydraulic and water treatment performance were monitored for more than six months with loading rates ranging from 1.3 to 2.5 gpm/ft2. Microbial parameters monitored during this period included cATP, tATP, and biofilm accumulation rate (assessed using biofilm coupons). PRE-CHLORINATION Pre-chlorination is occasionally practiced at DRWP to control midge flies, whereas HCWP biofilters never receive pre-chlorinated influent. To better understand the effects of pre-chlorination on hydraulic and water treatment performance, tests were conducted in two phases. A single biofilter from DRWP was monitored in the first phase from January 29 through May 31, 2019. Before starting chlorine addition, baseline performance was characterized for approximately 1.5 months with a 2.5 gpm/ft2 loading rate without any chlorine in the influent. Then, biofilter per-
A typical configuration of a municipal water treatment plant. Credit: vectormine, stock.adobe.com
formance was characterized for approxThe second pre-chlorination testing imately 2.5 months with a ~0.25 mg/L phase focused on isolating the effects free chlorine residual in the influent at of temperature changes from the effects 1.3 and 2.5 gpm/ft2 loading rates. continued overleaf…
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October 2021 | 47
WATER
Biofilters maintained with daily low-rate nonchlorinated backwashes had significantly lower turbidity compared to biofilters maintained with daily low-rate chlorinated backwashes.
of chlorine. Tests were conducted from August 20 through October 31, 2019, at both water plants with two biofilters (control and test). Along with hydraulic parameters, temperature, pH, turbidity, TOC, dissolved organic carbon (DOC), UV254. DBP and DBP formation potential (FP) were monitored during pre-chlorination testing.
ary 3, 2019, for construction activities to install UV disinfection downstream of the biofilters. Biofilter performance was closely monitored upon resuming biofilter operation to assess biological reacclimation requirements. From October 29, 2019 through December 17, 2019, short-term (72-hour) and longer-term (two-week) shutdown BIOFILTER SHUTDOWN AND tests were conducted at HCWP and MAINTENANCE STRATEGIES DRWP, respectively, assessing the effecThe HCWP was completely shut down tiveness of various biofilter maintenance from November 13, 2018 through Febru- strategies.
The testing focused on characterizing the effects of wet (i.e., media bed was completely saturated) or dry (i.e., media bed was drained, but remained moist) storage, daily aeration, daily water recharge with low-rate backwashing, backwashing the biofilter with chlorinated or non-chlorinated water, and backwashing the biofilter before shutting down and immediately before resuming operation. Along with hydraulic performance, water quality parameters including temperature, pH, turbidity, dissolved oxygen (DO), TOC, DOC, and UV254 were monitored in the biofilter influent and effluent. UPSTREAM PROCESS OPTIMIZATION Coagulant (aluminum sulfate [alum; Al2[SO4]3.14 H₂O]) dose and O3:TOC ratio optimization were included in the upstream process optimization testing. To assess the possibility of using lower coagulant doses and partially transferring TOC load from the coagulation and softening processes to the biofilters, coagulant optimization testing was conducted. The testing consisted of benchscale jar testing and full-scale coagulant dose optimization. Bench-scale coagulation and softening tests were conducted with DRWP and HCWP raw water to determine the optimal coagulant doses and quantify the amount of TOC that can be transferred to the biofilters with the optimal coagulant dose. Zeta potential titrations with coagulant and cationic polymer were used to determine the range of coagulant and polymer doses to be tested with the water samples collected from each water plant. Full-scale coagulant dose optimization was conducted at DRWP from July 10, 2019 to August 10, 2019, by lowering the coagulant dose from 90 to 50 mg/L in 5 or 10 mg/L increments every week. Biofilter performance was assessed in two biofilters, monitoring temperature, pH, turbidity, TOC, DOC, and UV254 in the raw water, settled water, softened water, and biofilter influent and effluent, along with hydraulic parameters. TOC RATIO OPTIMIZATION While both plants successfully met all treatment goals and are compliant with
48 | October 2021
Environmental Science & Engineering Magazine
all regulatory requirements since the addition of the intermediate ozonation, O3:TOC ratio optimization was conducted with the goal of lowering chemical costs without compromising overall plant performance. To avoid any potential complications due to temperature changes, testing was conducted from July 1 through September 12, 2020, with raw water temperatures at 24.7 ± 0.6 oC. Before changing the O3 dose, coagulant dose was lowered from 70 to 55 mg/L. Then, O3 dose was sequentially lowered from 3 mg/L to 2 mg/L, resulting in O3:TOC ratios of 1.19 to 0.82. Along with hydraulic parameters, coagulant dose, O3 dose, O3 residual in the O3 contactor effluent, pH, temperature, alkalinity, turbidity, TOC, DOC, and DBP FP were regularly monitored. RESULTS AND CONCLUSIONS Phosphorus supplementation did not improve biofilter performance with loading rates ranging from 1.3 to 2.5 gpm/ft2. This may have been due to the relatively low loading rates used throughout the testing (i.e., the margin of potential performance improvement may have been negligible), or the possibility that phosphorus was not in fact limiting in the biofilter influent. On average, 17% to 27% TOC removal was consistently achieved, leaving four biofilter effluent TOC concentrations below the city’s goal of 2 mg/L. Pre-chlorination with ~0.25 mg/L residual free chlorine resulted in lower headloss, without affecting TOC removal. On average, 20% to 30% TOC removal was observed, leaving consistently fewer than 2 mg/L TOC in the biofilter effluent. Haloacetic acids formed during pre-chlorination were completely removed across the biofilters while 58% to 71% of the total trihalomethanes formed during pre-chlorination were removed. DBP formation potential in the biofilter effluent was not affected by pre-chlorination. The occasional pre-chlorination at DRWP resulted in lower adenosine triphosphate (ATP) levels on the media samples collected from the top of the bed, suggesting the biological activity shifted deeper in the bed. Shutdown testing was impacted by
declining temperatures. When the average temperature difference before and after the shutdown was less than 5⁰C, TOC removal was similar before and after the shutdown, especially with wet storage and daily, low-rate, non-chlorinated backwashes. With an approximately 10⁰C decline in temperature after a two week shutdown, TOC removal decreased by 7% and 4% across the biofilter stored dry and wet, respectively, suggesting that wet storage might help minimize negative impacts of temperature decline and shutdown. Results showed that it may not be necessary to backwash a biofilter before shutdown if it is maintained wet with daily low-rate backwashes during the shutdown, and backwashed immediately before resuming operation. Biofilters maintained with daily low-rate non-chlorinated backwashes had significantly lower turbidity compared to biofilters maintained with daily low-rate chlorinated backwashes. Bench-scale jar testing showed that
similar settled water turbidity could be achieved with 5 mg/L cationic polymer and 50 mg/L alum, compared to 85 mg/L alum (the typical coagulant dose practiced at DRWP), which also would result in the transfer of ~0.3 mg/L TOC to the biofilters. The use of cationic polymer would reduce chemical costs and minimize waste sludge production without compromising settled water turbidity. Full-scale testing demonstrated that the cationic polymer dosed during the jar tests was not necessary. Lowering the coagulant dose from 90 mg/L to 50 mg/L at DRWP (full-scale) did not affect overall plant performance, and turbidity and TOC in the biofilter effluent consistently remained below 0.1 NTU and 2 mg/L, respectively. With the lower coagulant dose, approximately US$488,000 would be saved per year, while lowering disposal truck trips by 200 to 225. Lowering the O3:TOC ratio from 1.19 to 0.82 did not adversely affect biofil-
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WATER ter performance at DRWP. The biofilter effluent TOC was consistently below 2 mg/L. The implementation of the lowest O3:TOC ratio would save US$90,000 per year in chemical costs (liquid oxygen) and US$36,000 per year in power costs for ozone generation.
and the optimal O3:TOC ratio. Temperature exerted the largest impact on TOC removal throughout the study. However, based on this testing, utilities may want to consider wet storage and daily, low-rate, nonchlorinated backwashing during the shutdown. To better isolate the impacts of variRECOMMENDATIONS ous biofilter maintenance strategies, lonThis study demonstrated a holis- ger-term shutdown testing (greater than tic biofiltration optimization approach two weeks) should be scheduled for periand associated economic advantages. ods of limited temperature variability. The use of a lower coagulant dose and Utilities experiencing higher headloss O3:TOC ratio would maintain plant accrual in the biofilters could consider performance goals while saving signifi- pre-chlorination with low residual chlocant operations and maintenance costs. rine (~0.25 mg/L Cl2) in the biofilter influUtilities could consider optimizing the ent to improve hydraulic performance. coagulant dose and O3:TOC ratio so that However, full-scale evaluations should TOC could be partially transferred to, be conducted to fully understand the and removed across, the biofiltration step effects of pre-chlorination on biological without compromising treatment goals. activity, along with turbidity and TOC Full-scale testing should be considered removal across the biofilters. to determine the optimal coagulant dose, Profile sampling along the depth of TOC fraction that can be transferred to the biofilter bed should be considered to the biofilters, the impacts of additional determine how deep the chlorine peneinfluent TOC on biofilter performance, trates the bed and the resulting impact
on biological activity. Plants using inert biofilter media, such as anthracite, may observe a more significant impact to biological activity than plants using granular activated carbon media. Potential benefits of phosphorus supplementation can be site-specific, and C:N:P ratio assessment may not fully reflect phosphorus limitation in the biofilter influent. Utilities considering phosphorus supplementation as a potential biofilter performance enhancement strategy should consider enzyme activity analysis to accurately assess phosphorus limitation. For more information on WRF 4731, visit: www.waterrf.org
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EMERGENCY RESPONSE
Emergency response planning necessary to protect corporate assets By Anca Pop-Charles and Brian Edwards
M
ost businesses have experienced the need for emergency response in some capacity. For the minority that have not, the question has become not if, but when the need will arise. More than ever, the current environment in which businesses find themselves operating necessitates the adoption of an institutionalized and comprehensive approach to emergency response planning to protect corporate assets. Mitigation, preparedness, and recovery are critical phases of the emergency management process (Khan et al., 2018). To effectively manage a crisis, it is important to examine the underlying concepts of emergency response. A comprehensive emergency response plan ensures that emergent events are addressed quickly and allows for the timely implementation of established protocols in regard to resolution, recovery, and restoration of business operations. A business should have a designated emergency response team that is properly trained and familiar with the emergency plan strategy, as well as their respective roles in the process. While higher level officials in the organization should be responsible for activating an emergency plan, it is important that all employees and management are involved with the associated planning and training. This exposure increases familiarization and accountability throughout the business as a whole. The response to any emergency is crucial, as it ensures that the situation is controlled, recovery and restoration paths are established, and the emergency is addressed in a timely manner. The creation of a properly trained emergency response team with a defined communication plan helps all parties to understand the emergency and their respective role in the process. www.esemag.com @ESEMAG
Cybersecurity is a key issue to be addressed by new and emerging innovation districts, such as the one currently being planned for Lakeview Village in Mississauga, Ontario.
Development of the communication plan should include employees and management at all levels in every functional area of the organization, so that the team feels ownership of the process and will be more likely to support implementation when responding to the emergency. It is also important to note that, while response is coordinated throughout the organization, the formal declaration of a disaster or emergency should come from the executive management level in the organization. Defining roles and responsibilities before an incident takes place is of paramount importance. One individual cannot assume responsibility for an entire large organization. In some municipalities, an incident manager might be responsible for deciding the resources needed to address an incident, while a separate logistics officer might arrange for the resources needed, and a communications officer would speak to the media and public. These distinct roles can vary but need to be tested to ensure each role has the capacity and training needed to effec-
tively manage an incident. An organizational risk assessment will help identify the types of emergencies that may be encountered and their predicted effect on the organization. Emergency response activities can then be identified that will help alleviate the most impactful of those effects. Emergency response aims to help reduce the impact a disaster may cause (Khan et al., 2018). If there is no risk assessment undertaken, it is hard to determine that realistic scenarios for emergencies have been considered. While the safety of people should always come first in any emergency response exercise, there is also a need to assess the risk to physical property, the environment and intellectual property (IP). The risk assessment should find vulnerabilities and weaknesses that would create adverse impacts, and particularly those that are disproportionate to the magnitude of the emergency. Exposures could include building system deficiencies, gaps in security systems, and inadequate loss prevention continued overleaf… October 2021 | 51
EMERGENCY RESPONSE
Cyberattacks have become increasingly established as external threats that could negatively impact business operations. So this means companies must adopt secure cybersecurity measures…
programs. The risk assessment also evaluates the likelihood and the impact of a given threat or emergency, allowing the prioritization of response techniques or program enhancements. Some large public entities establish a risk severity matrix as part of their emergency response plan. While all emergencies require a plan, training and budget, not all are equally severe. Some organizations have four categories of incident that trigger differing responses, from a level one minor incident with no imminent threat to public safety or the environment, to a level four severe incident with imminent threat to public safety. Elements that trigger which level of response is required can vary, but who categorizes the incident is well established. Risk assessments should be updated when a shift in business operations takes place. A good example is the COVID-19 work from home shift, where a virtual private network (VPN) is now used by employees to access their organization’s server, and remote meetings and file sharing have become the norm. Under these circumstances, an IT risk assessment should be enacted to seek out vulnerabilities. It is critical to track the manner in which emergency response activities are carried out. The inclusion of performance indicators helps provide feedback to the organization on the effectiveness of the emergency response plan. Installation of building systems that can help detect and respond to unforeseen hazards can assist in emergency response situations, by helping to limit the impact that risk would cause. It is critical that emergency response activities work in concert with other hazard 52 | October 2021
prevention and handling techniques. Moreover, there is a need for a management system that recognizes the relay of information that would help manage hazards that occurred. One element often overlooked is budgeting for emergency preparedness. Having a budget to account for periodic training, plan reassessment and emergency simulations quarterly or bi-annually is imperative to ensure effective response. BUSINESS CONTINUITY After a disaster, an organization’s ability to maintain normal function depends on its ability to mitigate the impacts of the hazard, a concept referred to as business continuity. Business continuity planning should be informed by the risk assessment procedure, communication protocols, and other management activities intended to minimize business interruptions. The aim of the business continuity plan is therefore to re-establish critical operations as quickly as possible and revert back to normal operations. A continual process of business continuity development, review and enhancement should be part of any organization's core values, due to the unpredictable nature and ever-changing threat landscape. However, unforeseen situations may occur (such as a global pandemic) making it hard to implement a plan that keeps an organization operational as before (Fani & Subriadi, 2019). A comprehensive business continuity plan therefore considers various unpredictable factors. Cyberattacks have become increasingly established as external threats that could negatively impact business operations. So this means companies must adopt secure cybersecurity measures
that will prevent cases of unauthorized access to information and loss of data. Preventive security controls and user education are two key components that can help deter a cyberattack. If one does take place, users need to know how to quickly respond and use their incident response plan. The cyber incident response plan should include details related to identifying the incident, prioritizing response activities, isolating the affected components, recovery, follow-up and documentation of lessons learned. Historically, this process has been difficult for many organizations, resulting in a delay in resuming normal operations. The COVID-19 pandemic has complicated the implementation of business continuity plans for many organizations. For example, some organizations may not have the required manpower to implement business plans due to staff reductions and shifted priorities. As a result, the continuity plan must consider prioritizing essential tasks over others when not all aspects of the plan can be carried out. In this way, impacts to the organization can be minimized. It is prudent to note that setting up a business continuity plan requires significant finance and human resource allocation that not all companies may possess. The plan should also consider the funding required to implement various tasks, so those funds can be made readily available in a disaster scenario. Failover mechanisms can be decided upon by the organization’s administration once all the necessary components have been identified. Organizations can employ technology that helps maintain up-to-date copies of data over dispersed geographical locations. This would help an organization run effectively with all its information intact even after encountering a disaster. Data access can continue uninterrupted even when a disaster has shut down one location. It is essential to have a business continuation plan in place that considers all possible scenarios that could happen to an organization. Having a welllaid down program on approaching the occurrence is a good move that would help guarantee continuity even amid a disaster (Fani & Subriadi, 2019).
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The plan should help the organization have some degree of resiliency and respond with urgency to emergencies. Utilization of a business continuity plan helps minimize the financial and operational burden on the organization, while in many cases assisting the company in maintaining its public reputation and brand.
operation disruption from natural and human-made interruptions and seeks to handle them. Making contingency plans on how to deal with disasters is critical for any organization wishing to continue its operations after any type of disaster (e.g., tornado, pandemic, terrorism). It is essential to understand that disaster recovery is vital in all planning and DISASTER RECOVERY assessment processes. To guarantee Disaster recovery involves respond- effectiveness, there is a need to create a ing to the impacts of an emergency once functional recovery team that can assess it occurs. Natural events occur at a cost, the disaster risks that are anticipated. It and there has to be a plan to recover is also essential that critical applications from the impact on everyday operations and documentation are available. (Kadam, 2017). A backup plan must be established Disasters and disruptions can lead and specified to the teams involved. The to lost revenue for the organization plan should be able to work to ensure and brand damage. Once the company that there is normalcy even after the brand has been jeopardized, it is hard to occurrence of a disaster. redeem it to its usual position. Disaster Therefore, it is essential to ensure that recovery focuses on following a recovery there are better plans in place on how plan to bring production back to normal. to deal with problems associated with A good plan should guarantee a rapid natural calamities or even man-made recovery from disruptions of any kind. events that may disrupt normal funcIt also investigates all the aspects of tioning. Organizational planning and
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aligning of resources in readiness to handle such issues is paramount. Disaster recovery budgetary allocation should be considered to help hasten the manner in which response is delivered to the organization. Anca Pop-Charles is with Ross & Baruzzini. Email: anca.charles@rossbar.com Brian Edwards is with The Municipal Infrastructure Group Ltd., a T.Y. Lin International Company. Email: bedwards@tmig.ca (References are available upon request.)
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FAQs about level and pressure measurement technology for wastewater treatment
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roduction processes are becoming ever more complex. So, it is really important that the measurement technology used to control and monitor them is understandable and intuitive. Below are some frequently asked questions by water professionals: Is one radar sensor sufficient to provide level measurement and overfill protection at the same time?
Yes, one sensor is sufficient. VEGA Instruments’ VEGAPULS radar sensors are approved as overfill protection according to WHG (an official German environmental protection overfill standard) for exactly these cases.
It is really important that the measurement technology used to control and monitor wastewater processes is understandable and intuitive.
sate for water movement very well. Moving surfaces are a standard feaWhen do I need additional ture in water applications. Regardless overfill protection? of whether a container is being filled or In general, a redundant solution ob- water is simply flowing through a pump viously provides more security. VEGA shaft, radar sensors calculate a reliable radar sensors, however, also meet all average value from multiple reflected requirements as a stand-alone solution. signals. They provide a high level of safety and accuracy. Even the most noxious, cor- Do the sensors measure rosive gases or turbulent surfaces have through surface sludge? no influence on the measurement. Sludge is very compact and cannot be measured through. However, the What does the “Ü” symbol on surface height of the sludge can be the sensor mean? detected accurately, allowing a reliThe purpose of the “Ü” symbol on able level measurement. In contrast to the sensor housing is to help with foam, which is generally easier to meaidentification, because only VEGA ra- sure through, this does not work with dar sensors that are marked with a “Ü” sludge. If it is necessary to determine have WHG approval as an overfill pro- the exact height of the sludge, this can tection device. be done by combining a radar sensor and a pressure sensor. How do radar sensors react to In such cases, the radar sensor dewaves? tects the sludge surface, while the The influence of waves or turbulent pressure sensor detects the water levwater surfaces is minimal. With their el using hydrostatic pressure. The difvery wide dynamic range, VEGAPULS ferential indicates the thickness of the radar sensors measure even the small- sludge because its density is signifiest signals and can therefore compen- cantly different from that of water. 54 | October 2021
Are the pressure sensors resistant to acids and alkalis? The compact pressure sensors can be used for a variety of measuring tasks as the combination of stainless steel and ceramic covers a wide range of applications. VEGA has many pressure sensors in its product catalogue for applications with especially aggressive media. These are available in a wide variety of materials and versions for extreme requirements. Are there signal outputs other than 4 ... 20 mA? The sensors are available in different versions. The compact versions with the industry-typical 4 ... 20 mA. The cable versions with 4 ... 20 mA direct signal output, but also with other protocols such as Modbus. With Modbus, the instruments can be easily connected to existing data loggers. Cable versions are suitable for SDI-12 communication, often used for river and lake level telemetry-based measurements.
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Do the sensors with cable with the help of the adjustment tools. always need a controller? This makes it possible to directly disNo, for these sensors, either a 4 ... 20 play the current flow rate. A totalizer mA, Modbus, or a SDI -12 serves direct- integrated in the controller can also be ly as cable output. The radar sensors activated to store the total flow volume. work differently than ultrasonic transducers, which require a controller de- Will VEGA continue to make ultrasonic sensors? pending on the version. However, using a controller makes VEGA will replace ultrasonic technolsense if, for example, an additional dis- ogy in the long term. However, it will play is needed to provide more clarity be retained as long as there is customer on site. Pump control or flow measurement with totalization can also be realized with a controller. These functions, as well as a data logger, are integrated in the range of VEGAMET controllers.
demand. VEGA has had ultrasonics in its product range for over 40 years and is very familiar with the technology and its weaknesses. For more information, visit: www.vega.com
What data can I record in the controller? The digital controller for robust use in the field contains an additional data logger. An SD card that can store up to 100 million selectable measured values is included. How do I set up the controller for flow measurement? All controllers for installation in the field, in a control cabinet, or in a control panel have built-in linearization curves for flow measurement, which can be easily activated via the setup assistant. This means that the linearization curves for different flumes are already there, and only need to be selected and configured. A totalizer adds up the flow. Which Ex areas can the radar sensors be used in? In general, they can be used in Zone 0 or Zone 1. All sensors are also available in intrinsically safe versions. With encapsulation, the cable versions can readily be used in Zone 1. Because these do not need an intrinsically safe supply, and operate without a barrier, using them is easier than ever. Can the sensors also be used in open flumes? Yes, the integrated linearization curves make it possible. This applies to Venturi flumes as well as individual curves. Linearization curves are stored directly in the sensor or in the controller and can be easily assigned to a flume www.esemag.com @ESEMAG
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PERISTALTIC DOSING PUMP
Standardize on one chemical feed solution with the new FLEXFLO® M1 Peristaltic Dosing Pump. The self-priming M1 delivers smooth, consistent and precise chemical dosing with no danger of vapour lock or loss of prime. SCADA Inputs include: 4-20mA. Feed output range is .0001 – 5.6 GPH (.0004 – 21.2 LPH), pressures to 100 PSI .6.89 BarA sealed enclosure and a display shield protect the pump’s easy to operate controls from chemical spills and splashes. NSF STD61, ETL, and CE listed. Blue-White is ISO 9001:2015 Certified. Blue-White Industries T: 714-893-8529 F: 714-894-9492 E: info@blue-white.com W: www.blue-white.com
ROTARY LOBE PUMP
Boerger is expanding its portfolio with the new BLUEline NOVA Rotary Lobe Pump. This pump design sets new standards in pump technology and achieves unrivaled volumetric efficiencies. The newly developed DIUS rotors, combined with a flow optimized pump chamber, ensure perfectly smooth running even at high pressures. Available with a casing protection (Version NOVA Tough) or without a casing protection (Version NOVA Clean). www.boerger.com/newblueline/index.html Boerger T: 612-435-7300 E: america@boerger.com W: www.boerger.com
Environmental Science & Engineering Magazine
PRODUCT & SERVICE SHOWCASE
PIPING SYSTEMS FOR SODIUM HYPOCHLORITE
Chemline’s ECTFE Piping Systems for Sodium Hypochlorite is a proven, long-term rigid piping system solution for sodium hypochlorite applications in sewage and water treatment plants. ECTFE withstands oxidizing chemicals where other plastics fail. We offer single wall and dual containment systems, fusion machines and TSSA approved training, resulting in leak-free service and long-term value. Chemline Plastics T: 800-930-CHEM (2436) E: request@chemline.com W: www.chemline.com
ROAD MAINTENANCE
Consider a proactive approach to road maintenance this year. Many municipalities and private companies are utilizing Denso’s polymer modified–bitumen asphalt joint tapes to prevent water infiltration at joints. DensoBand and Denso Reinstatement Tape provide a permanent, flexible barrier between hot asphalt and steel, concrete and existing asphalt. Great for bridges, railway crossings and utility cuts. Contact Denso for more information. Denso North America T: 416-291-3435 E: sales@densona-ca.com W: www.densona.com www.esemag.com @ESEMAG
PIPE AND PRECAST PRODUCTS
BATTERY-POWERED CELLULAR FLOW METER
Endress+Hauser’s new Promag W 800 battery-powered electromagnet flow meter with cellular communications provides consistently accurate process and freshwater measurement in remote areas, even where there are no power or ground-based data lines. It provides highly accurate measurement with maintenance-free operation and worldwide data transfer via cellular radio for up to 15 years. It even supports integrated cloud connectivity. Endress+Hauser Canada T: 800-668-3199 F: 905-681-9444 E: info.ca.sc@endress.com W: www.ca.endress.com
ACCURATELY MONITOR POLYMER
The IBC TOTE SCALE™ from Force Flow allows operators to accurately monitor polymer used in the dewatering process when being fed from IBC type totes. Simply place tote on platform and monitoring begins. Systems prevent over and under feed conditions and also enable the documentation of amount fed. Available with the advanced Wizard 4000™ Digital Indicator, the SOLO™ G2 or the Century™ Hydraulic Dial. Force Flow T: 800-893-6723 E: info@forceflow.com W: www.forceflowscales.com
Forterra is a leading manufacturer of pipe and precast products. Our products improve quality of life, provide sustainable infrastructure and help communities grow and thrive. A specialized technical sales force, including engineers and field representatives, delivers a high degree of customer service and tailored solutions. Forterra delivers industry-leading service, quality, innovation and commitment. Our mission is to build the longest lasting infrastructure for our communities’ today and tomorrow. Forterra T: 519-622-7574 F: 519-621-8233 E: canada@forterrabp.com W: www.forterrabp.com
CHLORINE EMERGENCY SHUTOFF
Stop a chlorine leak within seconds of detection by automatically closing the ton container or cylinder valve. The actuator quickly mounts to valve without the use of any tools, and still allows the valve to be manually opened or closed. Halogen Valve Systems are the only systems that confirm that the valve was torqued closed to the institute recommended standard. Halogen Valve Systems T: 949-261-5030 E: info@halogenvalve.com W: www.halogenvalve.com
October 2021 | 57
PRODUCT & SERVICE SHOWCASE
WATERTIGHT DOORS
WATER FILTRATION SYSTEM
Harmsco’s WaterGuard™ Water Filtration System provides a “Whole House” water purification device that combines multiple filtration technologies utilizing ultraviolet sterilization. It is designed as a fail-safe unit that continuously improves the water supply by acting as a multi-layer drinking water sediment filter, adsorber and sterilizer. Harmsco Filtration Products T: 800-327-3248 E: sales@harmsco.com W: www.harmsco.com
CATCH BASIN INSERT
The LittaTrap Catch Basin Insert is a low-cost, innovative technology that prevents plastic and trash from reaching our waterways. Designed to be easily retrofitted into new and existing stormwater drains, the LittaTrap is installed inside storm drains and when it rains, catches plastic and trash before it can reach our streams, rivers and oceans. Imbrium Systems T: 800-565-4801 E: info@imbriumsystems.com W: www.imbriumsystems.com
58 | October 2021
OGS/HYDRODYNAMIC SEPARATOR
The new Stormceptor® EF is an oil grit separator (OGS)/hydrodynamic separator that effectively targets sediment (TSS), free oils, gross pollutants and other pollutants that attach to particles, such as nutrients and metals. The Stormceptor EF has been verified through the ISO 14034 Environmental Management – Environmental Technology Verification (ETV). Imbrium Systems T: 800-565-4801 E: info@imbriumsystems.com W: www.imbriumsystems.com
AUTOMATIC SELF-CLEANING SCREEN FILTERS
Experience – that is what sets ORIVAL Water Filters apart from competitors. Over 30 years under one ownership, with long-term application engineers on staff, makes ORIVAL, Inc. your reliable provider of filtration products. ORIVAL, Inc. has hundreds of automatic self-cleaning screen filter models with a filter for nearly every application. ORIVAL, Inc. T: 800-567-9767 F: 201-568-1916 E: filters@orival.com W: www.orival.com
Huber, a proven German manufacturer, now provides watertight doors that allow safe access to tanks for construction and/ or maintenance. Doors can be provided as round or rectangular for installation onto existing concrete surfaces or cast-inplace in new concrete. They can handle heads up to 30 m and hold pressure in seating and unseating directions. Huber’s watertight doors can greatly reduce construction and maintenance costs and dramatically improve safety/access. Pro Aqua T: 647-923-8244 E: aron@proaquasales.com W: www.proaquasales.com
HYPERBOLOID MIXERS
Invent Environment is the manufacturer of hyperboloid mixers which have revolutionized anoxic and swing zone mixing. Invent provides low-shear, efficient mixers with no submerged motors or gear boxes for easy access for maintenance. They have now released the Hyperclassic Mixer Evo 7 which has increased the number of motion fins and adjusted the geometry of the mixer to maximize mixer efficiency, reducing operation costs even further. Pro Aqua T: 647-923-8244 E: aron@proaquasales.com W: www.proaquasales.com Environmental Science & Engineering Magazine
ES&E NEWS FIRST NATION SIGNS $20M COMPENSATION DEAL OVER IMPACTS FROM NWT GIANT MINE
The federal government has agreed to set aside up to $20 million over the next decade as compensation for how the historical operation and cleanup of the arsenic trioxide-contaminated Giant Mine has affected the Yellowknives Dene First Nation. The former gold mine has been part of a history of “broken promises,” said Chief Edward Sangris, Dettah Chief of the Yellowknives Dene First Nation, who took part in the new agreements. The three agreements, called the Collaborative Process Protocol Agreement, Memorandum of Cooperation, and Community Benefits Agreement, were co-developed by the federal government and the Yellowknives Dene First Nation. They aim to address the environmental, economic and social priorities stemming from the legacy impacts of mining on the traditional territory. Between 1948 and 2004, the Giant Mine was a major economic driver for Yellowknife and the Northwest Territories. When the mine stopped operating, Canada became the site custodian. Remediation of the mine site started in July 2021. In addition to the removal of the arsenic trioxide waste, the project includes the demolition and removal of all buildings on the surface, and the remediation of surface areas, including the tailings ponds, water management and treatment options.
water treatment plants and landfills, as $16.6 million in new federal funding is released for northern infrastructure. The two biggest ticket items include an updated water treatment plant for the Hamlet of Tuktoyaktuk ($2.8 million) and the design and construction of a new landfill cell ($3.6 million) for the City of Yellowknife.
Tuktoyaktuk’s water treatment plant is set to receive new or upgraded water filtration, building heating and ventilation systems, a wastewater management system to handle new filter backwash requirements, as well as disinfection equipment and drinking water storage. Also set for the North in 2021 is a continued overleaf…
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FOUR WATER TREATMENT PLANT UPGRADES FUNDED ACROSS CANADA Water treatment plant upgrades have received funding for projects in New Brunswick, Saskatchewan, and the Northwest Territories. The biggest item among them includes $5.9 million in federal funding for the Saskatchewan Town of Outlook, where local officials are planning to add UV disinfection to the water treatment plant, while improving flow through its reservoirs. Also in the works is a new raw water intake in the South Saskatchewan River. Several communities in the Northwest Territories are set to upgrade their www.esemag.com @ESEMAG
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ES&E NEWS $3.7-million replacement water treatment plant for the NWT Hamlet of Sachs Harbour. It includes new funding for the replacement of the current water treatment plant, with a more modern treatment system. Previously, the plant struggled with the reliability of its chlorination equipment, which led to boil water advisories. New Brunswick’s community of PetitRocher will benefit from $4 million in upgrades that include the construction of a new nanofiltration water treatment system, along with the expansion of the existing pump station. Also expected is a new treatment system for the filtration backwash, connections to municipal
water services, and an expanded parking lot to accommodate growth. Petit-Rocher’s upgrades are expected to help end boil water advisories for some members of the community.
Strategy—expected to be finalized by fall 2022—is intended to identify measures and investments that increase the resilience of communities, natural ecosystems and biodiversity in the face of an ever-changing world. It will also establish a framework for measuring climate CANADA’S FIRST CLIMATE change progress at the national level. ADAPTATION STRATEGY ON The latest update from Environment TRACK FOR FALL 2022 and Climate Change Canada indicates The federal government says it is pro- that the average insurance payouts gressing successfully towards develop- related to extreme weather are estimated ing Canada’s first National Adaptation to have more than quadrupled (to $1.9 Strategy to fight climate change since it billion per year) over the past decade, began engaging stakeholders and part- with uninsured losses estimated to be ners early in 2021. double that amount. Canada’s first National Adaptation In 2021, Canada announced $3.7 billion in new investments related to climate change adaptation and resilience. This included investments in wildfire resilience, flood maps, health adaptation, and standards to support infrastructure resilience, as well as $1.9 billion announced in Budget 2021 to support provincial and territorial disaster response and recovery efforts. The Disaster Mitigation and Adaptation Fund was allocated an addition of $1.4 billion from Budget 2021 to the iniInsitu Groundwater Contractors tial $2 billion, to support projects such as wildfire mitigation activities, rehabili• Dewatering systems tation of stormwater systems, and resto• Mobile groundwater treatment systems ration of wetlands and shorelines. • Well and pump installation and maintenance
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60 | October 2021
CANADA INVESTS $16M FOR VERNON WATER FILTRATION SYSTEM IN B.C. The British Columbia community of Greater Vernon will see the construction of a new water filtration facility at its Mission Hill Water Treatment Plant among some $45 million in upgrades. New federal funding will allow the project to include a new water filtration system, a new building for labs and control rooms, upgrades to waste stream handling, piping and control systems. Greater Vernon Water delivers an average of 24 billion litres of water to more than 53,000 customers every year, through a grid of 650 km of pipelines that includes 57 pump stations. Kevin Acton, chair of the Regional District of North Okanagan Board of Directors, told media that the new filtration plant at Mission Hill will be “cruEnvironmental Science & Engineering Magazine
ES&E NEWS cial” in the face of already seen climate change impacts. In the fall of 2020, the Kalamalka Lake water source was shut off for Greater Vernon water customers due to an increase in algae. Additionally, a boil water notice from the historic 2017 flood resulted in economic losses of over $2 million. During the boil water notice in 2017, many Vernon businesses simply chose
Advertiser INDEX COMPANY PAGE ABB.......................................................3 ACG-Envirocan.............................50, 63 ACO Systems......................................32 Aerzen.................................................23 Asahi/America....................................50 Associated Engineering....................38 BARR Plastics.....................................31 BDP Industries.....................................2 Bestobell Aquatronix.........................41 Blue-White............................................7 Boerger...............................................40 CB Shield............................................11 Chemline Plastics..............................36 ChemScan..........................................41 Crane Pumps & Systems...................15 Denso..................................................22 Endress+Hauser.................................33 ERE – Environmental Remediation Equipment.........................................18 Force Flow..........................................43 Forterra..............................................13 Geneq.................................................35 Greatario............................................44 Halogen Valve Systems ....................37 Harmsco.............................................21 HRS Heat Exchangers........................41 HydraTek............................................34 Imbrium Systems..............................64 Interprovincial Corrosion Control....21 IPEX.....................................................27 LimeGREEN Equipment Rental........25 NETZSCH Canada...............................49 Orival..................................................45 Pro Aqua...............................................5 RTS Companies .................................48 Sentrimax...........................................17 Service Filtration...............................47 SPD Sales............................................53 Stantec...............................................35 Troy-Ontor..........................................39 Vanton Pump & Equipment..............19 VEGA Instruments, Canada.................9 Vissers Sales.......................................29 Water for People................................55
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not to use local water and purchased bottled water instead. Local officials had vowed to not let the ordeal occur again.
replace plastic and silica microbeads. “The eco-friendly conversion process developed by Anomera is also creating new, high-value market streams for the Canadian forest sector and is resulting CANADA FUNDING CONSUMER in non-traditional partnerships in cosALTERNATIVE TO PLASTIC metics and industrial applications,” fedMICROBEADS IN COSMETICS, eral officials said in a statement. SKIN CARE Specifically, the new $4.2 million in The federal government is investing funding will support the construction of $4.2 million in a Quebec-based cellu- a demonstration-scale facility that will lose nanocrystals company to support produce 250 tonnes per year of carboxthe innovation of an eco-friendly alter- ylated-cellulose nanocrystals and bring native product to replace microbeads for its cosmetics ingredients and industrial the consumer market. products to market, announced Natural Plastic and silica microbeads had been Resources Canada. popular in toiletries for their exfoliating Cellulose nanocrystals are celluproperties that acted as tiny scrubbers. lose-based nanoparticles that can be After it was determined that billions of extracted by acid hydrolysis from a wide them were washing down household variety of natural source materials such drains and out into waterways from as trees, annual plants, tunicates, algae wastewater systems, microbead prod- and bacteria. ucts were banned in Canada three years Anomera said it converts cellulose ago. This was the first step in an overall harvested from Canada’s sustainably single-use plastics ban. managed Boreal Forest into high-value, The new funding will go to Anomera biodegradable, environmentally friendly Inc., which has created a new class of replacements for the cosmetic and skinbiodegradable cosmetic powders that care industries.
October 2021 | 61
BIOSOLIDS
The HRS Unicus Series of scraped surface heat exchangers are well suited for thermal hydrolysis.
Thermal hydrolysis boosts biogas production from biomass By Matt Hale
T
he conversion of various forms of sustainable biomass, including food waste, crop and processing residues, manures, and sewage sludges, into biogas and advanced liquid biofuels has significant potential to contribute to renewable energy and carbon reduction goals. Hydrolysis is the process of breaking up the polymers that form lignocellulosic material (such as straw and woody biomass), to release molecules such as saccharides. This improves the efficiency of processes such as anaerobic digestion and fermentation in the production of bioenergy and biofuels. In most cases, hydrolysis utilizes temperature and rapid decompression (thermal hydrolysis), chemicals such as hydrochloric acid (chemical hydrolysis), or enzymes (biological hydrolysis) to break apart the lignin.
decompression. This combined action breaks apart the chemical bonds in the lignocellulosic material, improving biodegradability and allowing the organisms responsible for anaerobic digestion or fermentation to act on a greater surface area of material. This allows for higher loading rates or shorter retention times. In the case of manures and sewage sludges, the high temperatures involved also sterilize the feedstock, destroying any pathogens that may be present and opening up more options for the resulting digestate, such as its use as a high-quality biofertilizer. Although less used in waste and agricultural anaerobic digestion plants, hydrolysis (both thermal and biological) is commonly used in the water treatment industry to improve biogas production at wastewater treatment plants. It is also employed in the production of advanced biofuels for lignocellulosic THERMAL HYDROLYSIS feedstocks. The first full-scale applicaThermal hydrolysis is a two-stage pro- tion of thermal hydrolysis for sewage cess combining high-pressure heat treat- sludge was in Norway in the mid-1990s. ment of the feedstock followed by rapid Numerous experiments have shown 62 | October 2021
that increasing temperature during treatment can significantly improve sludge reduction and organic release efficiencies. Also, that multiple treatment cycles can be beneficial, depending on the nature of the treatment. The benefits of thermal hydrolysis include a reduction in the overall ratio of volatile solids, and improvements in the conversion rate of total organic carbon. The higher volatile solid content of sludge fed into the digestion system, and the higher degradation rate attained, cause higher biogas production compared to feedstock that has not been pretreated. HRS Heat Exchangers has developed a patented process for the continuous thermal hydrolysis of digester sludge using the Unicus Series of scraped surface heat exchangers. This involves heating the sludge to between 320°F – 338°F (160°C – 170°C), which changes the cell structure of the compounds, breaking down lignin and hemicellulose chains to create free sugars that are easier for the bacteria to digest. Consequently, residence times in the digester or fermenter can be reduced, and overall gas production improved. A steam explosion step can be included for extra efficiency. HRS offers patented processes for thermal hydrolysis both with and without steam explosion. These are based around a continuous process using scraped surface heat exchangers to avoid fouling, allowing more efficient production. Furthermore, the systems incorporate energy recovery to provide a significant cost reduction during operation, and the technology can be retrofitted to existing installations in order to improve their output. In the HRS process using steam explosion, the biomass is first preheated, and is then heated further at high pressure to achieve the thermal hydrolysis. The biomass is then transferred to a vessel for rapid depressurization. The steam that is released from this is then used in the initial preheating phase. The hydrolyzed biomass is then cooled before being passed to the digester. Matt Hale is with HRS Heat Exchangers. For more information, email: info@us.hrs-he.com, or visit: www.hrs-heatexchangers.com
Environmental Science & Engineering Magazine
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