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The evolution of water and wastewater associations

The first joint annual conference and tradeshow of the Ontario Water Works Association (OWWA) and Water Environment Association of Ontario (WEAO), taking place May 5 – 7 in Niagara Falls, will mark 42 years of involvement in the water and wastewater industry for me.

Many, many years ago, I attended my first OWWA conference and noticed that a significant number of attendees had also been at the WEAO conference. So, I asked, “why in Ontario were there two separate water and wastewater associations?” For the rest of Canada, associations included both water and wastewater members.

Due to this year being the first time that OWWA and WEAO have held their conferences together, I was recently asked this same question at an association meeting. My impromptu answer, based on what I could remember was, “it’s complicated.”

With my curiosity piqued, I re-read parts of a 1985 history book, entitled “Recollections: Water Pollution Control in Ontario”, which was commissioned by the predecessor of WEAO and authored by ES&E Magazine co-founder Tom Davey.

Chapter nine of Recollections covers in detail the evolution of water and wastewater associations. The first one in North America was the American Water Works Association (AWWA). It was founded in 1881 to allow an exchange of information about the management of waterworks.

The first Canadian Section of the AWWA was established in 1920 in Montreal. In 1971, the Canadian Section reorganized and three new AWWA Sections were formed: Atlantic Canada, Ontario, and Western Canada. Waterworks professionals in Quebec had received Section status in 1967. In 1973, the British Columbia Section was inaugurated, which meant there were now five Canadian AWWA Sections.

The Ontario Section of the AWWA restructured in 1995 and officially changed its name to the Ontario Water Works Association – A Section of AWWA.

As described in Recollections, during the early years of AWWA sewage treatment technology was not thought to be as advanced as what was used in the potable water field. The AWWA had held three conferences on sewage treatment, so the idea of forming a sewage treatment section was proposed. However, the proposal was rejected at the 1927 AWWA annual conference.

In 1928, recognizing the need for a wastewater association, some far-sighted individuals founded the Federation of Sewage Works Associations (FSWA). Initially, no annual conventions were held, but the Federation did launch the Sewage Works Journal. Equipment manufacturers promised to advertise in this new journal and other support came from the patent revenues of Dr. Karl Imhoff, the inventor of Imhoff tanks.

The FSWA became the Water Pollution Control Federation (WPCF) in 1960, which in turn was renamed the Water Environment Federation in 1991 to reflect an expanded focus on nonpoint and point sources of pollution.

In 1932, the legendary Dr. Albert Edward Berry called a meeting which resulted in the formation of the Canadian Institute of Sewage and Sanitation (CISS) in 1933. Dr. Berry

later became president of the AWWA and WPCF. In 1962, CISS changed its name to the Canadian Institute of Pollution Control (CIPC), in order to become a vital component in pollution abatement, technology and research.

In 1962, the Association Québécoise des Techniques de l’Eau (now Réseau Environnement) became the first provincial association formed to serve both the water and wastewater sectors.

In 1969, the CIPC briefly formed an Ontario branch, but it dissolved shortly afterwards.

The Pollution Control Association of Ontario (PCAO) was born from the Ontario Branch of the CIPC in 1971. The PCAO became the Water Environment Association of Ontario in 1993.

The Federation of Associations on the Canadian Environment (FACE) was founded in 1971 to create a national body. It was superseded by the Canadian Water and Wastewater Association, which was established in 1986 and continues to represent the common interests of Canada’s municipal water and wastewater systems.

A lot has happened in the water and wastewater sectors during the almost 40 years since Recollections came out. However, I am confident that the visionaries who helped to found the associations we know today would commend the great work done now by staff and volunteers who serve on the boards and committees of water and wastewater associations across Canada.

Having attended OWWA and WEAO annual conferences separately for over 40 years, I am looking forward to this year’s joint event. Let’s hope the clean water and the dirty water crowd feel the same way!

Steve Davey is the editor and publisher of ES&E Magazine. Please email any comments you may have to steve@esemag.com

US and Canada face 260,000 water main breaks annually, study says

By ES&E Staff

Arecent Utah State University (UTU) study created from utility survey data estimates that some 20% of water pipes across the U.S. and Canada are in need of replacement and contribute to some 260,000 water main breaks each year.

Water Main Break Rates in the USA and Canada: A Comprehensive Study was authored by Steven Barfuss, a research professor at USU in the Civil and Environmental Engineering Department, and an associate director at the Utah Water Research Laboratory. Barfuss estimates that the 260,000 annual water main breaks in North America equate to approximately $2.6 billion per year in maintenance and repair costs. The esti-

mate is based on a single water main break repair cost of $10,000.

Both the basic and detailed surveys showed that approximately 70% of utilities have a pipe replacement program. “Small water utilities may find it challenging to renew their water infrastructure in the coming years,” states the study. “They have lower populations with fewer customers per kilometre of pipe, which has the effect of increasing the financial burden of maintaining these systems.”

The average age of failing water mains according to the research was 53 years. The study, which tripled its sample size from its 2018 water main break research, found that four types of pipe materials comprise some 90% of water mains in

the U.S. and Canada. The mains are a combination of 29% PVC, 27% ductile iron, 23% cast iron, and 11% asbestos cement. The remaining materials each represent less than 3%. Additionally, the study found that some 86% of the water mains are 12-inch diameter or smaller.

“Utilities experience widely different break rates for the same pipe material,” the study states. “Indeed, this should not be surprising. Several significant variables affect break rates, including pipe age, soil corrosivity, corrosion prevention methods, installation practices, and climate.

These factors demonstrate why pipe material performance and selection are an important component of optimizing distribution systems.”

PVC pipe has the lowest failure rate among common distribution pipe materials in the study, while cast iron has the highest.

Barfuss also learned that overall water main failures between 2018 and 2023 decreased by 20%, which he correlated with reduced inventory of cast iron and asbestos cement pipe with high failure rates.

The study also notes that portions of Canada have “very corrosive soils” and “extremely cold weather”. These factors, says Barfuss, could potentially explain the higher Canadian break rates for cast iron (38% higher) and ductile iron pipes, the latter of which have a break rate triple that of the U.S. rate. Ductile iron pipe has more than six times the number of failures in highly-corrosive soils compared to low-level corrosive soils, Barfuss found.

Approximately 20% of installed water mains have not been replaced due to lack of funds, the study notes.

For more information, email: editor@esemag.com

Peel Region says wastewater expansion could support up to 47,000 new homes

By ES&E Staff

Ontario’s Peel Region is investing more than $335 million to expand the wastewater treatment capacity at its G.E. Booth Water Resource Recovery Facility by 40 million litres per day. Peel Region Council estimates that the increased capacity could support between 28,000 and 47,000 additional housing units, depending on the type of development, by 2028.

“Peel Region owns and operates the 2nd largest water and wastewater systems in Ontario and fourth largest in Canada, with world class systems and talent,” announced Peel CAO Gary Kent, in a statement. “This investment in our largest water resource recovery facility is dependent on future flow of development charges and ensures we are using utility dollars in the most sensible way to support effective long-term growth in Peel.”

The G.E. Booth facility originally went into service in 1955 with a capacity of 40 million litres per day. It currently has a rated capacity of 518 million litres per day. In late February, Peel Region Council announced an additional $130 million to “accelerate” the process of expanding it.

Peel officials said the increased capacity can be available sooner by advancing construction through their current capital contractors, ROMAG Contracting Ltd. and CIMA+ Canada Inc.

CIMA+ was retained as the design consultant under a competitive process for the replacement of the original portions of the plant in 2018. In 2019, council endorsed a plan to merge the replacement project with a planned expansion proj-

ect to advance the overall schedule and lower the risk of plant bypasses. This allows the plant to maintain its current capacity while the replacement of the original portion of the plant is completed. The combined project was tendered in 2022, and awarded to ROMAG Contracting Ltd. For

Peel officials said the increased capacity can be available sooner by advancing construction through their current capital contractors, ROMAG Contracting Ltd. and CIMA+ Canada Inc. Credit: Region of Peel

Urban stormwater control measures for nutrient management

By Julie Stein and Leila Talebi

Nutrients such as total phosphorus, orthophosphate, dissolved phosphorus, total nitrogen, total Kjeldahl nitrogen nitrate, nitrate+nitrite, and ammonia as N are commonly transported in stormwater runoff and are direct contributors to water quality impairments. Excess nutrients from stormwater discharges directly increase aquatic plant growth, harmful algal blooms and anoxia in receiving waterbodies, which adversely impacts fish and aquatic life.

Human activities are a common cause of excessive nutrient loading with specific activities, commonly tied to land use, contributing to high concentrations of nutrients in stormwater runoff. Activities such as urban or residential fertilization, septic systems, yard waste, organic debris, pet waste, trash and food waste, automobile emissions and atmospheric deposition are sources of nutrients discharging to our waterbodies via separate storm sewer outfalls or direct drainage via overland flow.

STORMWATER CONTROL MEASURES FOR NUTRIENT MANAGEMENT

A stormwater control measure (SCM), is an action, either structural or non-structural, implemented to manage stormwater by regulating its flow rate, quantity and/ or pollution levels. Studies over the past several decades have shown that, after source controls through actions like fertilizer bans and street sweeping, structural SCMs or best management practices are effective at removing nutrients in runoff.

Filtration practices such as media filters and high-rate bioretention are most effective for reducing total phosphorus and total nitrogen in stormwater runoff. Detention basins, retention ponds, wetland basins and wetland channels are most efficient at removing dissolved forms of nutrients in stormwater runoff.

Selecting SCMs for nutrient removal can be complicated given the number

of different parameters contributing to nutrient pollution and that specific SCMs are known to export nutrients. Bioretention, grass swales or grass strips, for example, may consist of phosphorus-rich soils or media, or cause ammonification or nitrification of organic nitrogen.

Combined with multiple pollutants of concern for waterbodies, it is important to know which nutrients are impacting a receiving waterbody and review data from the International Best Management Practices (BMP) Database to select SCMs that will address nutrient loads as well as other loadings. This database provides stormwater managers a centralized, online repository for the effectiveness of BMPs, as well as data on urban and agricultural runoff quality. This resource is particularly valuable for selecting SCMs to implement in watersheds that need to address multiple pollutants where competing costs or siting challenges are expected. These challenges can arise as utilities and public works departments try to fit SCMs into tight or constrained urban spaces.

MULTIFACETED APPROACH

A multifaceted approach is of utmost importance in addressing nutrient pollution in stormwater runoff due to the

complexity and scale of the issue. Nutrient pollution, primarily caused by excess nitrogen and phosphorus, poses significant ecological and public health risks. Adopting a multifaceted approach recognizes that nutrient pollution stems from diverse sources such as urban and agricultural runoff, sewage systems and industrial discharges.

By considering the wide range of sources, this approach ensures that strategies and interventions are tailored to address each specific contributor, maximizing the effectiveness of pollution reduction efforts.

Furthermore, a multifaceted approach acknowledges the need for a watershed-scale perspective. Stormwater runoff flows through interconnected watersheds, ultimately impacting downstream water bodies. By implementing strategies at various points along the stormwater pathway, such as source reduction measures, green infrastructure, treatment facilities and non-structural strategies, a multifaceted approach can effectively intercept and treat nutrients before they reach sensitive aquatic ecosystems.

This comprehensive perspective recognizes the interconnectedness of the stormwater system and ensures a holistic approach to tackling nutrient pollution, continued overleaf…

ultimately leading to improved water quality and healthier environments for both humans and aquatic life.

DETERMINE STORMWATER IMPROVEMENT GOALS FOR WATER QUALITY COMPLIANCE

These goals serve as clear and measurable targets and can be established in collaboration with regulatory bodies or through stakeholder consultation.

CHARACTERIZE EXISTING CONDITIONS AND ESTIMATE EXISTING NUTRIENT LOADS

This requires utilizing available data and employing modelling approaches to accurately assess the nutrient levels. In addition, it is important to consider all stormwater management practices and system assets that are currently in place or implemented at a specified point in time. This comprehensive characterization may require additional resources, such as historical information, environmental data and improved modelling approaches, to ensure accurate estimations.

CALCULATE REQUIRED NUTRIENT LOAD REDUCTIONS

These calculations are essential for developing targeted strategies and measures to achieve the established goals. Based on the existing conditions characterized above, in combination with water quality targets set by total maximum daily loads (TMDLs) or other assessments, the permit, and/or the watershed or stormwater management plan, specific goals can be determined to address impairments caused by stormwater. These goals typically involve specified reductions in stormwater pollutant loads or concentrations, volumes, or peak flows, and serve as benchmarks for effective stormwater management.

CHOOSING EFFECTIVE STRATEGIES AND MANAGEMENT ACTIONS FOR LOAD REDUCTION

This involves evaluating the effectiveness of various management practices, conducting economic assessments and adopting cost-effective approaches. Through the watershed or stormwater management planning process, opportunities for management actions are iden-

tified, including programmatic activities, low-impact development practices and municipal capital improvement projects. These strategies ensure that the selected management approach will lead to the attainment of water quality improvement goals.

MONITOR THE IMPLEMENTED MANAGEMENT APPROACH

This includes conducting ambient monitoring of the water body, tracking nutrient loadings and assessing the effectiveness of specific projects. Monitoring progress is crucial for providing feedback and assessing the effectiveness of the implemented measures.

TRACK AND ASSESS PROGRESS TOWARD GOALS

This assessment can be conducted through various methods, such as citizen observations, monitoring trend analysis and the development of quantifiable measures. It is important to report the results to stakeholders and the public. Developing quantifiable methods for evaluating progress is an area that requires further resources and research.

If progress falls short of expectations, it may be necessary to revisit earlier steps, reassess relationships and strategies, and make necessary adjustments. This assess-

ment process serves multiple purposes. It provides reasonable assurance to stakeholders and regulators, informs future stormwater program enhancements and capital improvement planning, and highlights quantitative results that support adaptive management, implementation tracking, and progress toward meeting stormwater improvement goals and requirements.

URBAN STORMWATER AND CONTROLS FOR NUTRIENT CHALLENGES

Numeric water quality criteria for nutrients in municipal separate storm sewer system (MS4) permits will always point communities toward a watershed or sub-watershed scale approach for SCM implementation. Implementing watershed-wide structural BMPs comes with its fair share of challenges.

Reporting data can be a significant hurdle. Collecting and analyzing data from numerous BMPs across a watershed can be complex and time-consuming. It requires establishing robust monitoring systems and ensuring data consistency and accuracy.

Local pilots, demonstrations and post-construction monitoring or data analysis can help communities determine capital investments. The Interna-

Detention basins, retention ponds, wetland basins and wetland channels are most efficient at removing dissolved forms of nutrients in stormwater runoff.

tional BMPs Database 2020 Summary Statistics Report spells out BMP-related data needs to provide pollutant removal effectiveness values for nutrients.

Particularly for nutrients, more data is needed relating to green infrastructure and their impact on potential nutrient export, how enhanced engineered media mixes (i.e., iron or biochar) may have positive effects on both nutrients and other pollutants of emerging concern and if nutrient recovery may be useful where soils are nutrient deficient (i.e., for a circular economy, to support agriculture).

Another challenge is the timeline for implementation, which is often identified in permits by regulatory agencies. Implementing SCMs at a watershed scale involves numerous projects and stakeholders, each with their own priorities and schedules. Coordinating and aligning these efforts can be time-intensive and may require overcoming logistical hurdles.

Additionally, securing funding resources for large-scale implementation can pose challenges, especially when considering the diverse range of sites and their site-specific considerations, such as land availability, soil conditions and local regulations.

Furthermore, evolving regulatory criteria present a challenge. Stormwater regulations and permits often undergo updates and revisions to address emerg-

ing concerns and scientific understanding. Keeping up with these changes, including stricter pollutant reduction, monitoring or reporting requirements, and ensuring compliance across a watershed, can be demanding for project planners and implementers. Staying informed and adaptable to evolving regulatory requirements is essential to the successful implementation of watershed-wide stormwater SCMs.

Potential future regulations in stormwater management may involve the adoption of new technologies and practices to improve stormwater quality. Costs of compliance with stormwater regulations can vary depending on many factors. These include the size of the watershed or community, the condition of the stormwater infrastructure, the level of pollution reduction required and the implementation of SCMs. Compliance costs may include infrastructure upgrades, maintenance expenses, monitoring and reporting activities, stakeholder outreach and staff training.

BENEFITS AND OPPORTUNITIES

One of the primary benefits of implementing SCMs at a watershed scale is improved water quality and ecosystem health. By implementing SCMs across a watershed, the overall nutrient and pollutant loads entering water bodies can be significantly reduced. This, in turn, improves water quality, enhances

aquatic habitat, and protects the health of plants, animals and humans who are all dependent on these ecosystems.

Implementing SCMs at a watershed scale often allows for multiple benefit projects. Many SCMs, such as constructed wetlands, permeable pavement and stormwater ponds, provide additional advantages beyond nutrient reduction. They can help manage stormwater volume, reduce erosion, enhance groundwater recharge and create green spaces that improve aesthetics and provide recreational opportunities.

By integrating multiple benefits into a watershed-wide approach, communities can achieve more comprehensive and sustainable stormwater management solutions.

Additionally, a potential future challenge that a watershed-wide approach can help address is climate change resilience. As climate patterns shift, communities may face increased stormwater challenges, such as more frequent and intense rainfall events. Implementing SCMs at a watershed scale can help build resilience and adaptability to these changing conditions by effectively managing stormwater runoff and minimizing its impacts on downstream areas.

Julie Stein and Leila Talebi are with HDR Inc. For more information about HDR’s water program, email negin.salamati@hdrinc.com

Associated Engineering Announcements

Associated Engineering is pleased to announce that Mark Sungaila, M.A.Sc., P.Eng., PMP, has joined our Toronto office as a Senior Project Manager. Mark brings over 37 years of consulting experience on solid waste management projects in the public and private sectors.

Also, Twyla Kowalczyk, M.Sc., P.Eng., IRP, is now Manager of the Water Resources Group in the Infrastructure Division in Calgary. Twyla has helped communities manage flood and climate-related risks and develop emergency response plans.

At Associated, we are passionate about building vibrant, healthy and resilient communities. Together, we can shape a better world.

Casselman starts chlorine dioxide oxidation pilot to solve water’s manganese issue

By ES&E Staff

The Ontario South Nation River Town of Casselman is planning to move forward with a chlorine dioxide oxidation pilot project to address rising levels of manganese that are turning tap water a yellowish brown. But local leaders say there will be many hoops of approval to jump through as the province wades through the technology’s unfamiliar waters.

In February, the town council extended its consulting agreement with Bill Dallala, a senior chemical engineer and water treatment expert with Montreal-based Krypton Scien-tek Inc., until summer 2024. Studying Casselman’s manganese challenges in fall of 2023, Dallala recommended that the town discontinue its use of chlorine gas and ammonium sulfate and rely instead on chlorine dioxide as a powerful disinfectant.

“The most powerful advantage of chlorine dioxide is that it’s much faster to oxidize manganese, or iron, and reduce turbidity levels in the water. Also, it does not react with carbon to generate trihalomethanes like chlorine does,” states Dallala’s 2023 report.

Manganese is an essential element for humans that occurs naturally in the environment and is widely distributed in air, water and soil. Health Canada’s maximum acceptable concentration for total manganese in drinking water is 0.12 mg/L. During summer 2023, Casselman’s levels often averaged between 0.35 mg/L. and 0.45 mg/L and even reached 1 mg/L in late July.

Casselman’s water remains safe to drink, despite the discoloration. But Dallala’s report adds that the town, located just southeast of Ottawa, “must also abandon” its chloramination technology and discontinue use of potassium permanganate to resolve the lingering manganese issue, which has

drawn complaints from residents.

He also told Casselman officials that he needs help from engineers to provide detailed drawings. The “time-consuming process”, he said, will be helped through a collaboration with J.L. Richards & Associates Ltd., as well as the Ontario Clean Water Agency, the provincial authority that operates and maintains Casselman’s water and wastewater treatment facility.

“This is a completely new way to treat water in Ontario,” states a public works update by Casselman staff on the water modification project. “Therefore, the Ministry of Environment Conservation and Parks does not have the expertise to provide feedback. The process to get the necessary approvals is long, as every step and action needs to be detailed quite elaborately to get the go ahead.”

Casselman has received a $1 million

federal grant to address manganese in its municipal water system. The municipality has also contributed $266,700.

Casselman Mayor Geneviève Lajoie told residents that she hopes they will notice a positive difference in the colour of the town’s tap water by spring, as the water modification pilot project gets underway. However, Dallala pointed out that testing will be challenged by the fact that manganese levels are often low during the winter and even spring months. It typically presents more aggressively in the summertime, he said.

For more information, email: editor@esemag.com

During the summer of 2023, Casselman’s manganese levels often averaged between 0.35 mg/L and 0.45 mg/L and even reached 1 mg/L in late July. This created a yellowish-brown hue in the water. Credit: andriymedvediuk, stock.adobe.com

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Saskatchewan’s $51M in water, wastewater funding will support 34 major projects

By ES&E Staff

Major water and wastewater infrastructure funding totaling more than $51 million was announced recently for Saskatchewan to support 34 projects that range from the addition of reverse osmosis systems, to ultraviolet disinfection, and new sewage pumping stations. The federal and provincial governments are supporting infrastructure upgrades in 17 communities.

Some of the most complex upgrades will take place in the Town of Redvers, which is set for a $6.1-million overhaul and process upgrade for its water treatment plant. The local council said it was “thrilled” with the news of its successful $4.5-million Investing in Canada Infrastructure Program (ICIP) grant, particularly after working on it at most council meetings since 2021.

BCL Engineering will replace the water treatment plant’s current greensand filtration method with biofiltration and reverse osmosis, according to Redvers council. However, officials said they will run a pilot project in the spring to determine what kind of water treatment system will work best.

“Embarking on this project will ensure that Redvers is not only compliant with the Water Security Agency, but also providing the best water to our residents directly to their taps today and in the future. This is an upgrade that was longawaited!” announced Redvers CAO Tricia Pickard.

More than $5 million in funding will also go towards upgrading the water treatment plants in the Northern Village of Green Lake, and the Village of Kincade. In the nearby Town of Lemberg, more than $3 million in upgrades will resolve meeting minimum requirements for bacteriological, turbidity, and chemical parameters.

The Town of Norquay has received funding to replace its existing water storage tank with an equivalent storage tank that is more cost-efficient. Credit: Mona Zubko, Town of Norquay

In terms of wastewater, Saskatchewan will see nearly $3 million in upgrades for the Town of Alameda’s sewage lagoon. A new cell will be dug to increase the town’s capacity and support future growth.

Nearly $5.5 million will also be invested in the Town of Vonda for a two-cell facultative lagoon that will span approximately 6.7 hectares. Its lift station is nearing its life expectancy, and the existing two-cell lagoon is undersized to meet the current and future needs of the community.

Lagoon upgrades are also set for the Town of Watrous and the Town of Whitewood.

In the Town of Cudworth, a new sewage pumping station will be constructed with wet well storage and pumps capable of meeting wastewater flows for 20 years. The project is expected to cost less than $2.5 million.

The Town of Pense and the Village of Pierceland are also set for wastewater upgrades. In Pense, nearly $1 million

will be spent to address ongoing issues with the condition and performance of the existing lift station pumps and process piping.

In Pierceland, more than $1 million will be spent on sewer pumps and piping to be upgraded for maximum efficiency, while creating less head pressure on the pumps. Crews will also upgrade measurement instruments and install an automatic generator to keep up with demands on the lift station when power is out.

Lastly, the Village of Plenty is set to install a new ultraviolet disinfection system, while the Village of Semans will install a reverse osmosis membrane filtration system.

For more information, email: editor@esemag.com

Regina water expert pioneers sustainable solution to transform sludge into multi-use ceramsite

By David Nesseth

When a water treatment expert at the University of Regina (U of R) learned that the nearby Buffalo Pound Water Treatment Plant was spending upwards of $1 million annually to transport and landfill water treatment residual (WTR) stored in on-site lagoons, he set up a meeting with plant management to explore innovative reuse solutions that not only promised substantial cost savings but could significantly diminish the plant’s environmental footprint.

Since 2022, Dr. Jinkai Xue, principal investigator at the U of R’s Cold-Region Water Resource Recovery Laboratory, and an associate professor in the Faculty of Engineering & Applied Science, has been working with his graduate students to explore residual volarization for the some 5,000 m3 of WTR that is produced each year at Buffalo Pound and then hauled to Moose Jaw, where the landfill has reached capacity. “That is expensive—both financially and environmentally,” Xue told ES&E Magazine

WTR, often called sludge, is created primarily from the process of coagulation and flocculation used to separate the suspended solids from the water. Xue says the sludge that eventually accumulates and settles on the bottom of the clarifiers is composed of different minerals, such as aluminum, calcium, magnesium and silicon, which are components of products like bricks, concrete and ceramics.

Xue’s research has since focused on the potential for the sludge to be converted into ceramsite, which forms small, coloured ceramic pebbles that can have environmental, agri-

continued overleaf…

Buffalo Pound Laboratory and Research Manager, Blair Kardash (centre) and U of R students collect sludge from the plant for the research project.

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cultural, or gardening applications for soil health. “We want to know what are the fundamental governing mechanisms that make this material good and how we can take advantage of that knowledge to make it better,” says Xue.

The research team discovered that the ceramsite pebbles have surprisingly high mechanical strength and durability that could be promising as a green construction material. With the right manufacturing process, Xue says they may meet the minimum compressive strength defined under Canadian standards for construction purpose.

Xue’s team is also conducting further studies to optimize the properties of the ceramsite. With a high capacity for absorption, the porous ceramsite also has the potential to be used for water pollution reduction. Xue’s tests have shown that putting a small amount of the material into water with high phosphorus concentrations can remove 90% of the phosphorus within 20 minutes, showing promise to address blue-green algae blooms.

“Once it’s been spent for nutrient removal, we can sell it to consumers as landscape mulch. At this stage, it is now saturated with phosphorus, which is a fertilizer that can promote microbial activities and soil health, which is beneficial for the plants. The entire process fits the circular economy strategy very well,” says Xue.

Researchers all over the world have been active in recent years looking for new ways to capitalize on the abundance of WTR. For instance, the University of Córdoba, Spain, recently developed a sustainable way to convert sludge into high-value activated carbon. Others are exploring avenues such as hydrothermal carbonization of the sludge to create an alternative solid fuel comparable to coal.

According to the Buffalo Pound Water Treatment Corporation’s 2022 annual report, the solids content of its sludge is only about 5% when settling out in the lagoon system. Prior to removal, the sludge undergoes a freeze-dry process that increases solids content to ~12% and decreases volume from 30,000 m3 to ~12,500 m3.

“After excavation, with difficulty, the very wet sludge is transported to a dry-

Xue’s research has since focused

the

the Natural Science and Engineering Research Council (NSERC) through the NSERC Alliance program, the Mitacs Accelerate program, and the Canada Foundation for Innovation – John R. Evans Leaders Fund (CFI-JELF) grant.

Whether ceramsite could become a practical and sustainable solution for WTR, and potentially reach commercialization, is a step to be considered further down the road. Xue acknowledges that there could be steep upfront costs when it comes to building a manufacturing facility, but there is no telling who could end up partnering on such a project.

Xue is hopeful that investors, or even various levels of government, could eventually propel the theories explored during the Buffalo Pound research into a practical reality, with the aim of furthering Canada’s circular economy.

For the research team at the Buffalo Pound plant, creating ceramsite from water treatment sludge in combination with other recyclable additives remains the most promising idea to date. Buffalo Pound Laboratory and Research Manager, Blair Kardash, says the high aluminum oxide content and nearly non-detectable levels of harmful metals within the plant’s potable water treatment waste “provided motivation” to find practical purposes for the material rather than hauling it to landfill.

ing bed where it undergoes evaporation, another freeze-dry cycle, followed by further evaporation,” the report states, noting that the solids content increases to ~30% and volume decreases further to ~5,000 m3. The sludge is dry enough to then haul to landfill.

Towards the end of 2023, Xue’s team received new sludge reuse funding of more than $118,000 from the federal government through Prairies Economic Development Canada, which recently introduced a framework to Build a Green Prairie Economy. This research partnership has been supported by

“If the research data at bench and pilot scales confirms this concept works, it then creates a foundation for the Corporation to pursue an environmental assessment,” Kardash told ES&E Magazine. “If the product passes an environmental assessment, the Corporation will look into finding an interested partner such as a third-party, individual investors, or government to pursue full-scale commercialization.”

The plant itself, which is currently immersed in a major expansion process, has come a long way towards building a greener identity. As of 2023, Buffalo Pound began drawing power sourced entirely from green sources, and even has a solar power project in the works.

David Nesseth is with ES&E Magazine. Email: david@esemag.com

Dr. Jinkai Xue is principal investigator at the University of Regina’s Cold-Region Water Resource Recovery Laboratory.

on

potential for the sludge to be converted into ceramsite, which forms small, coloured ceramic pebbles. Photos Courtesy of University of Regina.

Sewage sludge dewatering offers a wide range of potential savings for operators of wastewater treatment plants. The cost of transport and disposal of dewatered solids can amount to as much as 80% of the operating costs of mechanical dewatering. Since dryer solids result in less volume for disposal, the decision to invest in an efficient, reliable and, above all, peakperforming dewatering system is critically important to reducing operating costs.

“The Flottweg centrifuges and the dryer biosolids they produce have saved us about $900,000 annually. Our plant was able to incinerate the dryer sludge without the aid of natural gas, which equated to our high savings. The Flottweg centrifuges also produce cleaner and more consistent centrate.”

Greenway Wastewater Treatment Plant, Ontario

Ontario’s Excess Soil Registry rates jump

By ES&E Staff

Higher Excess Soil Registry fees for users will be spread out over five years instead of three, following feedback from a consultation period, says Ontario’s Resource Productivity and Recovery Authority (RPRA). But users might be taken aback by some of the increases.

The registry fees cover RPRA’s costs for building, maintaining, and operating the Excess Soil Registry, as well as providing support to registry users. Some of the fees will jump significantly for 2024. For the largest generators of excess soils (volumes greater than 500,000 m3) fees are going up by 400%, jumping from $30,000 to $150,000.

Also, projects that generated less than 2,000 m3 of excess soil did not have to pay registry fees last year. In 2024, however, those same projects will face a flat fee of $90. “The increase in 2024 fees for the Excess Soil Registry is required because substantially fewer filings and less soil volumes are being registered than RPRA had anticipated when the registry was built,” according to the RPRA’s consultation report.

The large fee increases will also impact owners of soil reuse sites. Fees to register for the largest of receivers (over 5,000,000 m3) are going up 250% from the current $12,000 to $42,000.

RPRA added that its 2024 program operating budget has been “reduced substantially” in response to the lower activity, although fee rates still need to increase, both to ensure full recovery of the reduced annual operational budget, and to recover program deficits that

have accumulated from 2021 through 2023, in part because of the low volumes.

Total operational deficits for RPRA at the end of 2023, not including registry capital costs, were estimated to be approximately $3.3 million. RPRA notes in the consultation document that it has “no other means of recovering its costs than through fees to registrants” and it does not receive any government or third-party funding.

RPRA explained that the discrepancy between earlier estimates for filings and current anticipated volumes is likely due to regulatory changes that exempted additional projects and, “potentially, to slow uptake of the program by registrants in its first two years,” according to the consultation report.

Throughout the consultation period, RPRA hosted a webinar to walk through the original proposal, answer questions, and gain feedback from registrants and other interested stakeholders.

Feedback during the RPRA consultation period suggested that the rate increases were too high, particularly given that 2024 project budgets were already approved, and that no new services were being provided to registry users. As a result, RPRA said it would “soften” the fee increase year-over-year and expand the time period to cover its deficit to five years instead of three.

Some of the fees will jump significantly for 2024. For the largest generators of excess soils, fees are going up by 400%, jumping from $30,000 to $150,000. Credit: Siggy Nowak, Pixabay

LimeGREEN marks a decade of success in rental equipment services

By ES&E Staff

Whether responding with equipment support for a six-alarm chemical distribution centre fire in Toronto, or assisting at the scene of a tractor-trailer pileup and diesel spill on a major highway, LimeGREEN has seen a lot of action over its 10 years in the field.

The Ontario-based specialized equipment rental company’s milestone anniversary highlights a track record of reliability and a reputation for a personal touch from founder Kevin Bailey and his LimeGREEN team, who have also heard a lot of “thank yous” over their first decade in business.

The company's core business includes industrial services, construction dewatering and remediation. “Clients see that everyone has a vested interest. When we get called to a site, we’re part of that team that’s called us there,” Bailey explains.

After he began developing and expanding a Canadian presence for U.S-based BakerCorp in 2005, Bailey was encouraged by those around him to stay in the business and start his own company.

The company came to be called LimeGREEN. The origin of the name is meant to symbolize the cleansing power of citrus and environmental sustainability. Both are elements that have been critical to the company’s success as it has built up an extensive inventory of liquid containment, pumps, and filtration equipment for a wide array of applications that cater to diverse industry requirements.

called upon for emergency response, particularly to help mitigate and contain spills.

“Our team’s commitment and ownership of their tasks resonate with clients,” Bailey emphasizes.

Bailey has been dealing in equipment rentals since his high school days, whether it was washing and servicing light equipment like pumps and saws, or driving equipment to job sites. But it didn’t take long before he began to cut his teeth in sales, marketing, and customer service, as he learned the ropes from mentors like Tony Joosse, Jon Brown, and Tony Brunet at Battlefield Equipment Rentals, and after that, under the wings of Jon Heslin, Tom Bullis, Jim Murray, and Joe Panzarella from BakerCorp.

“I owe a lot to those guys,” says Bailey. “They gave me insight as to what this business could be.”

Of all the mentors Bailey had, he says there’s a little bit of all of them in LimeGREEN as the company celebrates this proud milestone in its journey.

LimeGREEN now offers more than 15 different types of containment equipment through locations in Hamilton, Trenton, Sudbury, Ottawa, and Thunder Bay.

Despite its modest size, LimeGREEN’s word-of-mouth reputation precedes it. With a dedicated team and an ever-evolving inventory of tanks, Bailey ensures swift responses for clients and vendors across Ontario. The company exemplifies readiness and reliability when

Bailey remains humbled by the outpouring of gratitude his company receives from the industries it serves. He’s still amazed how often he’s caught off guard by gratefulness from clients. These moments, he reflects, affirm the significance of his work and fuel his passion for the industry.

“When a customer says thank you through a phone call, email, or text, it suddenly makes everything seem worthwhile,” Bailey says. “That’s why I’m doing this.”

For more information, email kbailey@limegreeninc.com, or visit www.limegreeninc.com

(Top) LimeGREEN founder Kevin Bailey. (Bottom) With a dedicated team and an ever-evolving inventory of tanks, Bailey ensures swift responses for clients and vendors across Ontario.

Ontario continues march towards streamlining EAs, introducing project list approach

By ES&E Staff

Ontario leaders have begun to shift the province to a project list approach for environmental assessments (EAs) as they kick off the spring sitting of the legislature.

The project list approach is part of the Conservative government’s upcoming Get It Done Act, which if passed, will mirror aspects of environmental assessments in Quebec and British Columbia that list types of infrastructure projects that would require the highest level of environmental assessment.

The project list approach is a shift away from the 50-year-old EA focus on project proponents, and a move towards

highlighting the nature of the project and its potential risks to the environment, according to an announcement from the Ministry of Environment, Conservation and Parks.

Ministry officials said a new project list approach would initially include highways, rail, and electricity transmission lines, all of which could be built up to four years faster through a streamlined EA process.

Other projects, however, could undergo streamlined EAs as well, as Ontario begins consultations to include municipal water, shoreline and sewage system projects. Consultations were held in 2020, 2021 and 2023 on the planned changes to move Ontario’s environmental assessment

program to a project list approach.

“Our government is supporting municipal partners by streamlining and simplifying complex environmental assessment processes to get shovels in the ground and finish major projects faster,” announced Ontario Minister of the Environment, Conservation and Parks, Andrea Khanjin. “We’re doing so while protecting strong environmental oversight and ensuring meaningful consultations before projects can move forward.”

In an announcement about streamlining Ontario’s environmental assessment process, officials illustrate the example of the comprehensive EA process for the East-West Tie Transmission Project that runs from Wawa to Lakehead in north-

ern Ontario. What took five years to assess under the former process, could be completed within two years under a streamlined process, officials estimated.

The ministry also noted that expropriation may soon be one of the ways that property can be acquired for a project before the EA process is completed. It is a point that comes as the Conservative government looks to invest nearly $98 billion over the next 10 years to expand public transit and build new roadways such as Highway 413 and the Bradford Bypass.

When it comes to creating a streamlined EA process for certain municipal water projects, provincial officials said it could accelerate project planning by limiting the process to six months instead of 18 months or longer.

“These time changes could be achieved by providing a regulated timeline, whereas under the current process there is no time limit,” the ministry announced. Approving a new large wastewater treatment plant, for instance, could be completed in just six months as opposed to the municipal class EA process that can currently take up to two years or more.

Steven Crombie, director of government and public relations for the Ontario Sewer and Watermain Construction Association, said that modernizing EAs for municipal infrastructure will help reduce the duplication of approvals necessary for the installation of low-risk infrastructure that is a required part of new housing developments.

“Streamlining this approvals process will save time and

resources for individuals, businesses, and government agencies without compromising any environmental outcomes,” Crombie said in a statement. “By simplifying regulations and reducing administrative burdens, Ontario is making it easier for businesses to operate and invest in growth.”

Ministry officials said a new project list approach would initially include highways, rail, and electricity transmission lines, all of which could be built up to four years faster through a streamlined EA process.

Credit: Enrique del Barrio, stock.adobe.com

Edmonton effectively upgrades large - diameter self-supported sewer line using grooved system

By Dave Horton

Wastewater pipelines are often buried underground in urban areas, but Edmonton’s system features a unique design and construction. The 900-millimeter-diameter sanitary sewer line crosses Whitemud Creek on a 232metre length and 30-metre high self-supported pipe, referred to as “Trestle 7.”

In 2020, EPCOR Water Services (EPCOR), the system owner, initiated a project to redesign the entire trestle, but the bridge’s existing architecture made maintenance and repairs impractical and cost-ineffective. EPCOR engaged with Victaulic to meet the project’s demanding timeline and budget constraints. This engagement not only facilitated a swift, cost-effective execution, but also provided additional advantages that enhanced the overall system design.

WHAT LED TO TRESTLE 7’S FULL SYSTEM REDESIGN?

Initially built in 1965 using carbon steel pipe, the appearance of corrosion began to highlight the system’s age and led to a decision to replace the Trestle 7 pipe. When an opening in the pipe required temporary patching, EPCOR’s in-house engineering team accelerated work to evaluate the long-term options. The general contractor, Whitson Contracting Ltd. (Whitson), constructed a massive scaffold deck across the creek to perform repairs, which enabled EPCOR to perform a complete redesign and replacement.

GROOVED SYSTEM TRANSLATES TO SIGNIFICANT TIME-SAVINGS

As a priority project, EPCOR established a one-year completion timeline for the truss design and pipe replace-

ment. To avoid future corrosion issues, a decision was made to replace the original carbon steel with stainless steel pipe. However, this triggered a new set of challenges that put the project’s budget and timeline at risk.

Stainless steel is more expensive to purchase, and its composition makes welding connections significantly more time-intensive than carbon steel. Extending the schedule meant lengthening the amount of time utilizing a wastewater bypass, which inherently increases cost and sewage spill risks.

“Our main concern was finding a way to reduce our time frame while still having reliable joints. That’s when we started looking at Victaulic, and we realized that what we might accomplish in weeks by welding, we would complete in days with a grooved system,” said

The Trestle 7 bridge transports Edmonton’s stormwater and wastewater across a 232-metre creek towards the city’s wastewater treatment plant. The redesign project removed the pipeline as a structural support and added walkways for maintenance use.

Abhishek Bhargava, senior manager of pipe strategies at EPCOR.

Installing Trestle 7’s new stainless-steel pipe involved 38 large-diameter joints. EPCOR predicted several problems with utilizing a welded system on a project of this scale and magnitude.

First, performing a single large-diam-

eter weld can take hours, and additional time must be built into the schedule to perform X-rays on each weld to certify joint integrity.

Second, they expected the installation to commence in the winter when freezing temperatures could make welding extremely difficult, elevating the risk of

cracking and poor weld penetration.

Third, the installation took place 30 metres above ground on a scaffold, raising significant safety and environmental (wind, hot-work) concerns. EPCOR approved using Victaulic’s Advanced Groove System (AGS) couplings after

continued overleaf…

(Left) Victaulic AGS couplings provide a fully self-restrained joint, ensuring a secondary restraint device wouldn’t restrict the new walkway space. (Right) A gantry crane was used to place and align 900-mmdiameter stainless steel pipe.

analyzing the time-saving benefits the mechanical solution offered for the project. The AGS coupling features a two-piece housing design secured using a pair of bolts, facilitating a faster, easier and safer installation.

SELF-RESTRAINED SOLUTION REDUCES MATERIAL COSTS

The sanitary sewer pipe supported the original bridge structure, leading to elevated concerns over the bridge’s longterm structural integrity. In response, EPCOR removed the sanitary sewer pipe as a structural component during the redesign. Its engineers used a series of eight trusses to provide the necessary structural support and added a walkway to the sides of the pipe to ensure operators could safely inspect and perform maintenance on the system.

Separating the pipe from the structure meant additional support was needed to restrain the sanitary sewer system, which was subject to high wind conditions at its altitude. Initially,

EPCOR planned to add expansion joints to provide the necessary dynamic movement, but it wasn’t necessary in the end. Engineers eliminated that cost by utilizing Victaulic AGS couplings.

The AGS system provides a fully self-restrained joint, eliminating the need for a secondary restraint device. This engineered solution reduced material costs and avoided encroaching on the new walkway space that will be critical to maintenance ease in the future.

EASE OF INSTALLATION IN CHALLENGING CONDITIONS

Site conditions on the Trestle 7 project were a significant challenge during the installation process. Whitson and their mechanical sub-contractor (Land Air Contractors) needed to cross 232 metres of pipe over the creek and execute work 30 metres above ground within a strict construction schedule.

The installation also occurred during the frigid winter months and at the peak of the COVID-19 pandemic, further

diminishing the expected ease of installation. The grooved system enabled crews to reduce installation times and material handling for a safer, quicker job.

RETURNING TO NORMAL WITH AN IMPROVED SYSTEM

The Trestle 7 project was successfully completed on schedule, and normal services resumed in November 2021. Bhargava said the new design will make it easier for operators to inspect and maintain the system decades down the line. “The new walkway allows them to safely monitor the movement and performance of the system. If a joint loosens up, they can easily tighten up bolts. If a section needs to be replaced, that can be done without needing to cut and reweld the pipe or build an entire scaffold.”

Dave Horton is with Victaulic. Email: dave.horton@victaulic.com, or visit www.victaulic.com

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Nutrient management facility soon underway in Red Deer to reduce phosphorus

By ES&E Staff

Preliminary demolition work was scheduled for this spring for the construction of a new $19-million nutrient management facility (NMF) in Red Deer, Alberta, as local officials aim to extend the life of pipes and pumps impacted by struvite.

The retrofit project at the existing wastewater management facility will separate phosphorus from Red Deer’s biosolid wastewater stream. One bioreactor cell from the original biological nutrient

where crews battled struvite buildup in pipelines and equipment for years following anaerobic digestion.

By converting a minimum of 85% of the available orthophosphate into crystalline form (or leaving no more than 50 ppm remaining in reactor effluent), the phosphorus recycle stream back into the plant was broken, according to the Belgium-based company.

The nutrient management facility project in Red Deer is scheduled to be

we are

a better, more sustainable

Wetland constructed at Moncton snow disposal facility to protect waterways

By Leigh Patterson

Runoff from municipal “snow dumps” can be especially problematic, containing gravel, salt and hydrocarbons from oil and gas, among other things. But newly released results from a City of Moncton wetland project constructed by Ducks Unlimited Canada are showing promise as part of the solution.

Adam Campbell, manager of Ducks Unlimited Canada’s provincial operations in Atlantic Canada, spearheaded the wetland’s construction in his former role in environmental services.

“In 2014, we constructed a shallow wetland below the snow disposal facility to filter snowmelt runoff, which is one of the many important things wetlands do,” said Campbell. “Created to mimic a natural wetland, it cleans the water by slowing and capturing sediment, filtering particulate and absorbing excess nutrients.”

The 1.6-hectare wetland is between Moncton’s snow disposal facility just outside the city in Berry Mills and a local watercourse, Jonathan Creek. The small watercourse was exposed to annual meltwater runoff and the wetland was intended to protect it from potential contamination.

Each year, snow is placed by the city on a specially built pad and the meltwater flows from there into the wetland, where it is held and filtered, aided by salt-resistant vegetation. For nearly a decade, city staff have been monitoring the snowmelt surface water collected by the wetland.

In its 2024 report, Historical analysis of water quality monitoring at the Berry Mills snow dump facility, the City of Moncton indicated that initially in 2014 and 2015, water quality was monitored only for the outlet point of the wetland (SW0). However, since 2016, water quality for both inlet (SW1) and outlet (SW0) of the wetland was monitored every year, except for 2019, 2020 and 2022.

Water sampling is usually carried out

each year in the spring (April – May) when snow melting starts from the disposal site. A special sampling program began in September 2018 to monitor water quality in the wetland in snowfree season.

The purpose of the monitoring is to document water quality, including general chemistry, trace metals and total suspended solids in the inlet and outlet of the wetland which receives melt water from the snow disposal site and discharges to downstream spillway.

All parameters were compared with the Atlantic Risk-Based Corrective Action Tier 1 EQS Surface Water Guideline and the Canadian Council of Ministers of the Environment Water Quality Guidelines for the Protection of Aquatic Life. It is understood there are no specific discharge criteria for the meltwater runoff. The city used these guidelines as a reference only.

The city’s report presents historical analysis of some of the water quality parameters such as chloride, pH, total suspended solids, iron, copper, alumi-

num, barium, cadmium, and lead, which have exceeded guideline values in more than one year. Other parameters such as fluoride, manganese, nickel, vanadium, and zinc exceeded guidelines in only one year, mainly at the inlet point. No detailed analysis is presented for these parameters.

Overall, results show a reduction in chloride levels between 66% to 93% when comparing water samples from the inlet and outlet of the wetland. These results suggest that the wetland is functioning well in reducing chloride levels before the meltwater enters the watercourse.

“We’re pleased with the results we’ve seen so far,” said Tim Moerman, director of environmental planning and management at the City of Moncton. “Clearly wetlands and green infrastructure can go a long way towards filtering a lot of the pollutants that get scooped up during snow-removal operations.”

Campbell is also very positive about the results of the project, what they have learned, and the prospects for expanding this practice across the region and country.

Aerial photo of the newly constructed wetland and the snow dump pad above it.

“We are fortunate to have a wetland policy in the province of New Brunswick that protects wetlands from loss,” noted Campbell. “Naturally occurring wetlands provide us with so many services. They are true natural assets and it is important to appreciate these functions and protect them.”

This isn’t the first time Ducks Unlimited Canada and the City of Moncton have worked together on innovative natural solutions to address urban water quality challenges. In 2015, the city drafted naturalized stormwater management guidelines which set parameters for constructing retention ponds, recognizing that managing stormwater can be done in a way that adds to the quality of

A photo of a Moncton naturalized stormwater pond (Fairview Knoll) designed to receive stormwater runoff. Photos courtesy of Ducks Unlimited Canada

Toronto’s new wastewater energy project could be first of many as partners share experience

By David Nesseth

One Toronto project is showing the untapped resource power of the some 175 billion litres of wastewater flowing through North American sewers every day.

By changing the temperature of that wastewater by just 1°C, and temporarily diverting it, cities could generate some 60 billion kilowatt-hours of clean energy annually, replacing traditional cooling towers and natural gas boilers with building climate systems that harness the carbon-free thermal energy of wastewater.

“This is wastewater that flows predictably with predictable flow rates as well as a consistent temperature that is between 10°C and 25°C year-round, and that’s regardless of climate for the most part,” explained Cam Quinn, vice-president, engineering – North America, at Noventa Energy Partners, who presented on the benefits of wastewater energy transfer for a March webinar hosted by ES&E Magazine

The webinar attracted participants from municipalities, institutions and consulting firms across Canada. The session featured speakers from the City of Toronto, Noventa, R.V. Anderson Associates, and IPEX, who sponsored the webinar and is a supplier of the Toronto Western Hospital project, which is nearing completion as one of the largest raw wastewater energy transfer (WET™) projects in the world.

The Toronto Western Hospital project soon hopes to be saving nearly $685,000 per year and reducing 8,400 tonnes of CO2 equivalent annually as it finalizes a switch from fossil fuels to a cutting-edge wastewater energy building climate system.

Toronto’s buildings currently account for nearly 60% of its greenhouse gas (GHG) emissions. Under the city’s TransFormTO plan to displace fossil fuel use in municipal buildings and transition to a low-carbon strategy, Toronto aims to get to net-zero by 2040 or sooner.

“It’s kind of an incredible project actually to decarbonize an entire hospital campus,” said webinar speaker Fernando Carou, who is the director of smart buildings and energy management with Toronto Community Housing.

While getting this first major wastewater energy exchange project off the ground as a proof of concept requires

lots of heavy lifting, Carou explained during the webinar that it also means a much easier way forward for other projects yet to come.

Property owners and energy developers in Toronto can use an existing online map to determine whether there is a sewer in the vicinity of their site that can potentially be used for a wastewater energy project.

There are opportunities for wastewater energy projects all over the city, and Carou estimates that at least 300 MW can be harvested throughout Toronto to displace fossil fuels on a massive scale.

“This could support many more sys-

The Toronto Western Hospital project broke ground in spring 2022 and is set to be fully operational by the second quarter of 2024. Credit: Bird Construction

tems the size of the hospital and more,” Carou said.

Just as Toronto has climate goals, so does the University Health Network. The Toronto Western Hospital project is estimated to reduce the hospital’s GHG emissions by more than 250,000 tonnes over the next 30 years. But it will not only reduce the massive facility’s carbon footprint, it will also save some 12 million gallons of water per year as it replaces cooling towers with a system of heat pumps and heat exchangers.

The wastewater heating and cooling system is a closed loop that is not as affected by outdoor weather conditions like cooling towers, which can lose thermal efficiency on hot, humid days.

“Essentially, instead of rejecting heat to the atmosphere, we’re rejecting heat to the sewer,” Quinn said of the system’s cooling operation.

The wastewater energy exchange project will supply more than 90% of the annual space heating and cooling

demands for the hospital. The estimates include 10 MW available for heating and 9 MW for cooling.

In heating operation, the system extracts heat from the sewer instead of rejecting heat to the sewer, Quinn said. Heat pumps can then be used to increase or decrease temperatures to desired set points.

“The beauty of it is that we can use the same setup that we use for heating to do cooling,” Quinn added.

While natural gas-fired boilers can produce hot water or steam at around 80% thermal efficiency, Noventa’s WET system has an efficiency several times higher, Quinn said.

The WET system can also balance the building’s thermal energy loads.

During summer operations, for example, when the load is cooling-dominant and rejecting heat to the sewer, some heat can be diverted for domestic water preheating or other heating demands.

Noventa Energy Partners is the waste-

water energy project developer and owner of the Toronto Western Hospital WET project. They are also the exclusive North American provider of the HUBER ThermWin® technology that is used in the system.

The Toronto Western Hospital project broke ground in spring 2022 and is set to be fully operational by the second quarter of 2024.

R.V. Anderson Associates Limited (RVA) is providing consulting engineering services to Bird Construction as part of the wider design-build team and is a major subconsultant on the Toronto Western Hospital project.

Mark Bruder, a project manager and senior associate at RVA, shared the engineering challenges around constructing the project’s wetwell, connecting with the trunk sewers, and building the energy transfer station.

The wetwell is the large, vertical, underground structure that facilitates

(Left) The wetwell shaft appears to have a green glow due to a specialized spray to coat the walls. (Right) The complicated wetwell is approximately 39 m below the surface and Noventa needed a design that had the ability to convey upwards of 1,200 litres per second from the MTI sewer. Credit: Bird Construction

access to the sanitary sewers. It houses a new wastewater screening and pumping system for the hospital that is connected to the 120" diameter concrete sewer main.

Bruder showed webinar participants pictures of the base of the wetwell shaft during construction, where it appears to have a green glow. He said this is because the team had to use a specialized spray to coat the shaft’s walls, as the Georgian Bay Formation shale bedrock around the shaft is known to expand.

“It swells, it expands and it actually moves in the space that you’ve excavated,” said Bruder, noting that the coating has stress relief properties, and the team had to make sure there was a compressible layer in between the concrete and bedrock

Inside the wetwell is the technology responsible for diverting and screening wastewater from the mid-Toronto interceptor (MTI) sewer, as well as the conveyance of screened wastewater to and from the energy transfer station and finally, returning the wastewater to the MTI sewer.

This complex wetwell is approximately 39 m below the surface and Noventa needed a design that had the ability to convey upwards of 1,200 litres per second from the MTI sewer.

“In this case, tapping into the sewer super deep in a congested urban environment was pretty tricky,” Bruder said at the ES&E webinar.

The system utilizes four submersible pumps at the base of the wetwell shaft. They each have a target flow rate of 300 litres per second. Each pump has a dedicated forcemain to convey wastewater to the energy transfer station, where the heat exchangers interact with the wastewater.

The system then utilizes a gravity return line to convey wastewater back to the wetwell shaft.

Finally, the system then mixes the screened wastewater solids with the return wastewater for it to be sent back to the MTI.

During the webinar’s Q&A session, enthusiastic questions from participants explored details of the project, such as heat exchanger maintenance and cleaning, service agreements, sewer prox-

imity to projects, and potential downstream impacts to treatment plants.

Some participants also wondered about the ability to scale down wastewater energy exchange technologies to the residential level.

“It could be set up as a district energy system that’s just in the right spot with multiple customers,” Quinn said. “If it’s a shallow sewer that has a good flow rate, you can probably get down to a much smaller installation and get a business case that makes sense.”

Carou noted that scaling down the technology often means balancing the capital costs of the endeavour with the potential energy savings.

However, as the technology becomes more integrated into Canadian cities, Carou said there’s no telling what type of innovation could be around the corner.

“I wouldn’t be surprised actually that as wastewater becomes more mainstream, there will be more new technologies to take advantage of the resource.”

For more information, email: editor@esemag.com

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Spring marks crucial test for NB biosolids composting facility

By David Nesseth

Come spring 2024, the TransAqua biosolids composting team in Moncton, New Brunswick, will have a stronger sense of whether the latest retrofits to their GORE Cover system are working to more effectively reduce odours that have created tension in the city’s north end for several years.

A third-party audit of the facility’s system in summer 2023 revealed that ongoing modifications may have eventually compromised aspects of the GORE system.

“We’re trying to squash all those bugs,” Nicolas Cormier, TransAqua’s new interim board chair, told ES&E Magazine. “Small modifications eventually stack up to make a big change, and we were losing some of the benefits of the GORE system because of some of these modifications made. It could have been a value-engineering effort.”

At the top of the list was addressing an issue that arose as part of the initial installation of the system, potentially as a cost-saving measure, when composting operations began in 2008. That setup did not include concrete berms next to the compost piles, says Cormier, who notes that the berms aid the function of creating what amounts to closed-bag seals that keep the covers in place when they balloon up and down during aeration. “As a result, leachate just has a very easy time just sneaking out underneath the cover on the sides and on the end.”

Several new pads have already been built to the proper standard and more work continues to be done for the concrete berm retrofit. “Spring I think is going to really be the big test for us,” adds Cormier.

The facility’s composting process is carried out on three outdoor concrete pads of 56 x 50 metres. This large pad is laid out to have eight compost windrows 50 metres in length.

The GORE system is essentially intended to simulate “being inside a building without requiring a building,”

explains Cormier. An actual building, however, is exactly what Moncton City Council recently voted for as a potential solution to ending odour complaints from residents, with the hope that a structure would contain more of the odour. The other alternative council voted for in an early 2024 resolution was for TransAqua to relocate its operations entirely, far away from residential areas.

As the number of residences near TransAqua’s composting facility have grown over the past two decades from a handful of homes into the hundreds, so grew the opportunities for complaints to be called into the municipality.

Complaints actually began in 2021, following the completion of a major upgrades project at the wastewater treatment plant. Secondary treatment was added, as well as UV disinfection. But it remains unknown why there is a connection between the timing of the upgrades and the beginning of the odour complaints, particularly after composting operations had already been in place for more than a decade.

At a city council meeting in December 2023, Moncton Councillor Bryan Butler shared his experience of sitting

on a constituent’s deck one evening in the north end to illustrate the struggle and frustration felt within parts of the community.

“If somebody told you tomorrow to be prepared, and you had to sit in an outhouse at a construction site all night, that’s kind of like what they’re smelling every day. Every time the wind blows, they get this smell,” he said.

As one of the movers of the January motion that intended to put more pressure on TransAqua, Butler said it was simply time to do something more, even if it meant a largely symbolic motion, as TransAqua is a corporate entity created by the province, and not under municipal direction. “We want people in the north end to have the quality of life that they deserve,” Butler told council.

Following Moncton council’s recent push to resolve the north-end odour issues once and for all, Cormier says TransAqua officials recently met with the New Brunswick Department of Environment and Local Government to understand the extent of council’s authority, and affirm whether the composting site, which is a taxpayer-funded operation, is still operating within its legal parameters.

The facility’s composting process is carried out on three outdoor concrete pads.

The province has been involved with the north-end odour issues challenge previously and will likely conduct a new assessment in spring 2024. Part of previous department efforts was to pinpoint the source of the odour complaints. The culprits were narrowed down to the Eco 360 landfill, the Rayan Environmental Solutions scrapyard, and of course, the TransAqua facility.

“There are some recycling plants nearby. There are farms nearby. So, even if we put into effect the perfect solution, it’s not going to eliminate all of the odour complaints in that area from our perspective,’’ says Cormier, who is also the Director of Project Engineering for H2O Innovation in Quebec.

As long as proximity remains a factor, Cormier says it won’t be a surprise to see complex relationships continue between biosolids composting facilities and the neighbouring public. More than a decade ago, a biosolids composting facility co-owned by the British Columbia municipalities of Vernon and Kelowna, faced odour complaints as it fine-tuned its processes to produce fertilizer. More recently, the Alberta Town of Strathmore faced residents frustrated by biosolids composting odours from the Huxted Waste and Recycle facility.

“Operators at the facility have fixed the aeration pipes,” the municipality’s communications team wrote in 2018. “They are currently breaking down the turned pile, allowing for easier management of the compost. They are also integrating biofilters, commonly used to treat foul airstreams, and a neutralizer spray to significantly reduce the odour.”

Back in Moncton, a working group involving the municipality, the province, and most of the facilities suspected of creating odours, have already tried to get to the bottom of the public’s complaints. A provincial online form was created for residents to document odour complaints, even allowing for them to speculate specifics such as wind speed and direction.

Following that venture, Hive Engineering established an odour complaints phone line while it conducted air quality testing throughout the summer and fall of 2023 with fixed monitoring stations. The Hive team received nearly 100 “sewage/compost” odour phone calls in September alone, greatly exceeding other categories such as chemical or burning odour complaints.

Of the 74 volatile organic compounds able to be detected in the air near the facility, Hive only found 16, and all were below guidelines, a representative told Moncton council in December 2023.

When TransAqua started to get odour complaints in 2021, its team immediately took several actions, including their own odour investigation. They covered the compost piles; increased air blower times to decrease moisture and humidity; replaced mechanical mixers with hydraulic mixers at the wastewater facility to create more uniform sludge; and increased flushing of wet wells to eliminate wastewater, to name a few.

Other key odour mitigation actions taken include the installation of a fogging system to help neutralize fugitive odours at the compost facility; transport and disposal of biosolids at another approved facility; increasing the biosolids to bark ratio; and monitoring wind direction prior to turning compost piles.

Before any new significant odour mitigation efforts are

undertaken, though, Cormier says he wants to be sure they’re on the right track. “I sometimes worry that inaction is taken as not taking the issue seriously. As an engineer, I’m a datadriven person,” he says. “I just want to make sure whatever money is spent isn’t done so foolishly.”

While odour complaints have grown, so too has the quantity of high-quality compost, rich in nitrogen, phosphorus and other micronutrients, which is collected each year from self-loading bins without charge by the residents of the Moncton area. By 2020, public pickup data for compost at the facility reached nearly 6,600 tonnes, out of an annual output total of about 9,300 tonnes.

TransAqua’s team says that the key to its composting process is the mix ratio of biosolids, wood wastes, and other green wastes. The result is a biosolids compost product referred to as Gardener’s Gold Compost, a compost soil conditioner and compost mulch that often exceeds Category A quality standards from the Canadian Council of Ministers of the Environment.

Treatment of sludge at the WWTP involves conditioning with liquid lime, and use of high-speed centrifuges for dewatering, followed by the addition of dry lime.

David Nesseth is with ES&E Magazine. Email: david@esemag.com

Perfecting wastewater pretreatment for direct potable reuse

By Patrick Murphy

Water scarcity and source water contamination concerns are fueling ever-increasing interest in the practice of direct potable reuse (DPR) systems. DPR uses many of the same wastewater and drinking water treatment systems currently in place, but instead of putting the treated wastewater back into the ground, the water is stored to be withdrawn as needed by the water treatment plant (WTP).

In order to ensure the highest quality water, DPR systems often use ultrafiltration membranes in place of a tertiary wastewater treatment, or as a pretreatment before storage. This pretreatment process, which also includes disinfection and other remediation processes, must be properly designed to ensure the water will be effectively treated by the WTP.

ADVANTAGES OF DIRECT POTABLE REUSE

The main appeal of DPR is that it allows communities to conserve water and build resistance to drought. Additionally, there are these advantages:

• It offers superior water quality to most drawn and treated source water, often exceeding regulatory standards for drinking water.

• It produces more consistent water quality than surface or groundwater, which can vary in composition, challenging WTP operators.

• Contaminants such as PFAS, industrial solvents, and even microplastics are successfully removed from DPR water during the wastewater treatment phase, ensuring they do not re-enter the drinking water system.

• As a largely closed loop, DPR waste-

Instrumentation such as turbidity analyzers (left) and chlorine analyzers (right) are key to ensuring pre-treatment processes in direct potable reuse are working as required. Such instruments can communicate directly with chemical metering pumps in order to correct water quality when parameters are too far out of tolerance for the quality level desired.

water isn’t returned to a water source and little to no source water is withdrawn from water sources, minimizing any potential impact.

IMPORTANCE OF PRETREATMENT

DPR water treatment consists of many stages, including primary, secondary, and sometimes tertiary wastewater treatment. The treated wastewater is then prepared for storage in anticipation of being withdrawn by the WTP and treated to drinking water standards. Pretreatment occurs between these key stages and consists of turbidity reduction and disinfection.

Effective pretreatment is critical for several reasons, including:

Health and safety – Pretreatment minimizes pathogens that can proliferate during storage and cause potential problems for the drinking water treatment process and ultimately customers.

Taste and odour – Even after running through the drinking water treatment processes, insufficient pretreatment can result in issues with odour and taste.

Treatment efficiency – Excess turbidity can disrupt the treatment process. In the worst-case scenario, this can cause clogs in filters, pumps, or other equipment. In addition, turbidity can shelter

pathogens from disinfecting agents.

Cost – Any or all of the above could result in added costs associated with downtime, equipment failure, increased operator hours, and more.

Compliance issues – The most concerning result of insufficient pretreatment is failure to meet regulatory requirements, causing issues for the water utility and/or treatment plant managers.

PRETREATMENT DESIGN CONSIDERATIONS

With pore sizes of 100 nanometres, or smaller, ultrafiltration membranes excel at removing a wide range of viruses, bacteria, cists, and other pathogens that wastewater treatment does not eliminate, and which could proliferate to harmful levels in storage. Thus, an effective pretreatment process for DPR must include both ultrafiltration and disinfection. However, there are several considerations that must be taken into account for the system to work as intended.

MEMBRANE DESIGN

In DPR using ultrafiltration, the membranes do most of the heavy lifting for turbidity and contaminant removal. For the most effective pretreatment, it is critical that the system is carefully maintained

and properly backwashed. For example, the system should be set up with multiple membranes, with each entering a backwash cycle every 30 minutes or so.

INSTRUMENTATION

In order to ensure proper pretreatment, the system should monitor water quality before and after storage. This can include the use of level sensors, turbidity analyzers, chlorine analyzers, and more. Ideally, for disinfectant and other chemicals, sensors/analyzers should have the ability to communicate directly with metering pumps to maintain required dosing levels.

DISINFECTANT

While ultrafiltration significantly reduces the amount of disinfection needed, it is still critical to have effective disinfection as part of the pretreatment process to ensure that what few pathogens may remain are kept below harmful levels. There are many types of disinfectants that a DPR system can employ. For example, ozone and peracetic acid (PAA) both break down into safe substances, such as oxygen and water.

The longest-standing and most costeffective disinfectant, sodium hypochlorite, is ideal for a wide range of applications, and using chlorine for pretreatment in DPR is no exception. The chemical’s strong oxidation power and the fact that it remains in solution in water for a long time, continuing to work, makes it ideal for water storage.

A peristaltic pump like the one pictured above is a key component in a direct potable reuse pre-treatment system. Such pumps can precisely administer chlorine and other chemicals as required.

EQUIPMENT COMPATIBILITY

Regardless of what chemicals are used in pretreatment, it is important that the system be designed with the proper equipment. This includes choosing which metering pump is the best choice to dose the chemical in use, as well as ensure material compatibility.

Perfecting pretreatment in DPR ensures high-quality water that meets

regulatory standards. Taking into account the above factors, a well-designed pretreatment system can contribute to the sustainability and reliability of a DPR system and the community it serves.

Patrick Murphy is with Blue‑White. For more information, visit www.blue‑white.com

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Confined space is just one material handling challenge facing wastewater plant operators

By Steve Napieralski

The need to handle materials safely and efficiently is omnipresent in the wastewater sector, as it is in the myriad of end user marketplaces that use cranes and other hardware.

OZ Lifting makes cranes, manual and electric hoists, beam trolleys, winches and components, and davit cranes.

A davit crane is different to a jib crane. The two products might be similar in appearance, but portable davit cranes are more cost-effective and versatile and are more popular with those sourcing lifting equipment for wastewater applications. OZ Lifting first introduced its CompOZite (composite) davit to the Canadian market two decades ago.

The popularity of such systems derives from ultra-portability and construction from advanced lightweight composite material. This material reduces the weight of the crane by 40% compared to traditional steel models, making it easier to transport and manoeuver. In one recent application, a distributor provided four CompOZite davit cranes and 80 pedestal bases, with the intention of mounting bases around the facility and moving the davits.

Despite this lighter weight, such davit cranes can boast a lifting capacity of 1,200 lbs. and require no tools for assembly. Additionally, they feature a 360-degree rotating arm and an adjustable boom with four positions for increased versatility in various work environments.

The composite material construction also offers corrosion-resistance for enhanced durability; for the same reasons, stainless steel hoists, winches, and wire rope assemblies are also widely used by the sector.

Wastewater professionals typically source davit cranes, and other material handling technologies, from manufacturers’ distribution networks. OZ Lifting, for example, has coverage in every province, from industrial distributors to lifting and rigging specialty dealers. Many are broad material handling houses, but there are Canadian distributors that specialize in wastewater solutions.

CHALLENGING INDUSTRY

As the entire supply chain reports, the water industry presents a number of challenges to material handling applications, including confined space, corrosive environments, heavy components, and extreme outdoor weather conditions, especially in Canada.

Perhaps the most obvious is confined space. As is the case in multiple industries, it is necessary to lift, lower, turn, and move loads where it is seemingly inconvenient to do so. In fact,

where there is ample space, lots of headroom, and plenty of ground to install equipment, there is little or no need to handle materials there.

Many treatment plants have narrow spaces everywhere, such as those commonly found at pump stations or around digester tanks. Lifting gear needs to be manoeuverable and compact to navigate these areas to complete maintenance or repairs. These workstations are often operated by only one or two people, so davit cranes, hoists and winches need to be continued

Dropping a pump can be costly and dangerous and will present an even bigger problem trying to retrieve it safely in an unplanned lift. As such, robust handling systems are essential.

THE EVOLUTION OF THE CHEMICAL METERING SYSTEM

Up to 50% reduction in mechanical room space required 90% fewer joints = 90% less risk of leakage Simple, consolidated operation AFTER simple. intuitive.

lightweight and portable.

Fast and efficient setup and ease of use are prerequisites. With the composite davit crane referenced above, a ratchet screw jack adjusts the boom under load, giving the user a complete range of lift.

The environment around such facilities is inherently corrosive. Further, wastewater can be abrasive and contain harmful chemicals and biohazards. Material handling equipment must be resistant to these elements to ensure durability and safety,

not just at the first time of use, but in repeated application. Consider the difference in environment between a sewage works and an indoor warehouse, and the different demands each one places on material handling equipment.

Another challenge is the heavy components found at wastewater sites. Purchasers working in water treatment often approach their local material handling dealers with a need to lift, remove, or install heavy pumps, pipes, valves, and other hardware.

Lifting and transporting such loads requires robust handling systems. Dropping a pump can be costly and dangerous and will present an even bigger problem trying to retrieve it safely in an unplanned lift.

In all parts of the world, wastewater facilities are often exposed to the elements, which means that particular attention has to be paid to geographical location and the extremes it

It is necessary to choose an appropriate base for davit cranes. Wheel bases allow users to move the crane within a facility.

might present from high summer to the middle of winter. Wastewater treatment facilities are often located near bodies of water like lakes, rivers, or even coasts, so moisture, humidity, and saltwater corrosion are of concern. Durable, corrosive-resistant coatings and materials are used to protect the apparatus, including cranes, that needs to work there.

This is where stainless steel and composite materials come into play. Unlike an indoor, temperature-controlled environment, Canada experiences a wide range of extremes, from scorching summers to frigid, snowy winters, but the equipment needs to be able to operate, regardless.

Only once the load, environment, and all other challenges have been considered, can a wastewater professional, a lifting equipment manufacturer, and its representatives, set about choosing the right crane, hoist, beam trolley, winch, and supporting components.

Using the appropriate equipment reduces wear and tear, minimizes unnecessary stress on the products, extends their lifespan, and reduces replacement costs. On the other hand, using the wrong lifting equipment can lead to accidents and injuries. Lifting a heavy object with an under-capacity hoist could result in equipment failure, dropping the load, and serious incident. Having the right tools for the job streamlines the process and contributes to overall operational efficiency, lowering total operational expense.

CHOOSING THE RIGHT BASE

Throughout a wastewater facility, there might be a need for permanent, static, or frequently moved davit cranes. Regardless, it is necessary to choose an appropriate base for them.

A pedestal base is commonly bolted to the floor in a facility. Users just mount the base where they need to make a lift and move the crane from base to base.

Socket bases are used in an area where the installer will pour cement around the base to keep the surface area flat and create high mounting strength.

A wall mount base allows a davit crane to be attached to the wall of a facility to save floorspace, perhaps on a production line or at a workstation.

Finally, wheel bases allow users to

move the crane to various points within a facility; the applications are limitless. The main benefit is that users do not have to permanently mount a base. The wheel base is adjustable with four different length positions. It weighs 64 kg. when fully assembled, without a crane’s pedestal base, so total weight will depend on the davit being used.

The wheel base features a patented

floor anchoring system, which allows the davit to rotate 360 degrees, even when under load. Without the correct base, users will not be able to use a davit crane.

Steve Napieralski is with OZ Lifting Products LLC. Email: steve@ozliftingproducts.com

Consulting engineers need to learn how to help clients navigate the current climate crisis

By Kadra Branker and Kenzie Lewis

Amidst the changing climate policy landscape, consulting engineers are being urged to adopt circular principles and similar methods to help their clients successfully navigate the current climate crisis. Engineers hold the potential to shape a sustainable future through their decisions and influence.

Climate action involves both adapting to the impacts of past greenhouse gas emissions (GHG) and mitigating future ones by swiftly reducing emissions. It is crucial to address both aspects to navigate the climate crisis effectively. The discussions and actions coming out of the recent COP28 meetings are a good reminder to revisit how to achieve mitigation targets, with 2023 being the hottest year on record.

Terminologies that continue to be confused in the climate change space are ‘climate mitigation’ and ‘climate adaptation’. It is helpful to understand that they are different responses to the climate crisis. Climate mitigation is our response to increasing manmade GHG emissions by taking actions to reduce or eliminate emissions. Climate adaptation is our response to the impacts of a changing climate today and in the future because of GHG emissions that have already been released or that will continue to be released.

These are often thought of separately, and mitigation often dominates the discussions as we try to prevent the worst from happening. While there is a significant need for action in the climate mitigation realm, the longer we take to act on significantly reducing our global emissions, coupled with the ‘sunk’ emissions of the past, the more important it is to consider adaptation today and into the near future.

POLICIES AND REGULATIONS

A review of some recent climate change discussions points to a shifting policy landscape requiring more action on climate mitigation and adaptation. The credibility and implementation of programs and policies will depend on having licensed engineering practitioners contribute to the climate mitigation and adaptation work ahead of us.

Engineers have a role as problem solvers, helping their clients navigate this changing climate and economic policy landscape without causing further harm. While fossil fuels have enabled the innovation and quality of life many of us enjoy today, it has come at a price; and it is unlikely that the same types of isolated and linear problem solving will lead to better outcomes.

As a result, consulting engineering firms should consider expanding in-house skillsets or partnerships in areas such as climate science, climate change resilience and adaptation, circu-

lar economy design applied to economy wide decarbonization and adaptation and decision making under uncertainty, and adaptive decision making.

APPLYING CIRCULAR PRINCIPLES TO CLIMATE MITIGATION

The theory of the circular economy is not new. Systems thinking, which engineers are well-equipped to do, can be a fundamental tool to implement it. The economy and society cannot exist without the environment and nature. A simple recap of circular economy principles to be applied to design is to eliminate, circulate and regenerate.

Reflecting on the way we make and consume materials and energy, it is easy to see how current methods create waste and pollution, are inefficient, and deplete natural systems. For example, as we race to decarbonize our energy systems with renewable energy technologies like wind and solar, supported by batteries, we risk making the problem

Global critical mineral demand for clean technology, 2022 compared to scenarios in 2030.

worse through using fossil fuels to produce and transport the products from limited resources, only to dispose of the limited resources at the end of their life.

Recent commitments at COP28 to further increase energy efficiency and moves to improve tracking and reporting of Scope 3 GHG emissions are good initial steps. However, we will continuously need to evaluate how targets are met, with solutions being assessed for circularity.

This could lead to designing products beyond single use or single life and retaining the usefulness of the product or its components for as long as possible, such as feedstock for other processes. Recapturing the value of potential waste streams is not only helpful from a climate change perspective, but also from an economic perspective, which can lead to societal benefits.

APPLYING CIRCULAR PRINCIPLES TO CLIMATE ADAPTATION

When thinking about climate adaptation and resilience, a systems thinking approach would urge assessing these measures alongside climate mitigation actions, and vice versa. Some adaptation and resilience measures, or lack thereof, may lead to increased energy use and material waste.

Some examples are, the increased need for fossil-fueled backup systems due to the increasing frequency of extreme events; the increase in energy use for cooling systems as the planet warms; and the continuous repair and replacement of damaged infrastructure on a more frequent basis.

Similarly, some mitigation solutions could lead to maladaptation, such as not accounting for the changing availability of weather-based energy for renewable technologies, which could leave a particular area vulnerable in the future due to a lack of power. Improved solutions would consider both mitigation and adaptation, with circular economy principles aiding this process.

BLUE BOX REGULATION CHANGE IN ONTARIO

One example of how the regulatory landscape is already changing in Canada is the adoption of an Extended Producer Responsibility (EPR) recycling model

by several provinces, including British Columbia, Saskatchewan, Quebec, Manitoba, Alberta, and Ontario (Circular Materials, 2023).

In Ontario, an EPR model will result in major changes for businesses that produce recyclable materials. The change in regulation will transition municipalities across the province from a system in which the government is responsible for

50% of the cost of recycling to a system where all costs and responsibilities are placed on companies that produce recyclable materials, known as producers.

Producers will be required to facilitate curbside collection of materials, manage the recycling procedures for the materials, and submit reports on their actions and how much material was col-

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lected (Resource Productivity & Recovery Authority, 2023). This change will also facilitate a transition from a system with over 240 different lists of accepted recyclable materials to a system where all municipalities will accept the same Blue Box materials (Government of Ontario, 2019).

Engineering consultants will be integral to ensuring that businesses manage the new Blue Box regulation. Engineering will lead to innovative strategies for redesigning products to minimize, eliminate and manage waste, maximize recycling profits, and ensure compliance. The expertise of engineering consultants on sustainable materials, production techniques, and disposal practices will be of value to companies that are looking to thrive under the new regulatory framework.

THE NEED FOR MORE RENEWABLE ENERGY WILL DRIVE DEMAND FOR CRITICAL MINERALS

Achieving net-zero by increasing renewable energy will result in a significant increase in the consumption of limited critical minerals and waste generated. Global demand for critical minerals for clean technology is expected to grow by almost 2.5 times by 2030.

Canada’s installed wind power is expected to grow by a factor of 1.5 in this time, whereas the global installed capacity is expected to double, leading to an estimate of Canada’s need for critical minerals for wind energy to grow by about three times. Similarly, Canada’s installed solar power is expected to grow by almost three times by 2030, whereas the global

installed capacity should grow by a factor of six, leading to Canada’s need for critical minerals for solar PV to potentially grow by about 1.5 times by 2030.

Additionally, the increase in clean technology production may increase electronic waste in Canada, which has tripled in the past two decades and is expected to keep rising in the future.

Engineers have a role in addressing both the rise in demand for critical materials and increase in electronic waste in Canada. One approach is to utilize circular economy principles by ensuring that materials are reused or recycled in a continuous fashion, or, by considering more abundant and available materials and material sources in designs.

Engineers should consider designing electronic equipment that facilitates the reuse, dismantling, and recovery of waste materials (European Union, 2012). Research has shown that up to 90% of materials used in solar cells can be recycled, which could provide an estimated 78 million tonnes of raw materials and valuable components globally within the next 30 years.

Given limited availability of critical minerals and the pace of the energy transition, engineers should strive to select materials that are already available. To meet the growing demand for critical minerals as the world transitions to net-zero energy, it is thus imperative for engineers and consultants to design with circularity in mind.

CLIMATE RESILIENCY AND ADAPTATION IN TUKTOYAKTUK

Climate change is already causing irreparable harm to communities across Canada. For example, the community of Tuktoyaktuk, Northwest Territories, is undergoing rapid changes to the landscape. Due to climate-exacerbated coastal erosion, Tuktoyaktuk is losing approximately two metres of land per year. Climate change is causing the permafrost layer underneath the community to thaw, which is causing residential lots to slip into the Beaufort Sea.

Engineering measures have been somewhat successful at slowing this erosion. Protective concrete slabs, as well as breakwaters made of boulders or other materials, are installed along sections of the shoreline to reduce the force of the incoming waves. New construction is built on top of gravel pads to keep the permafrost intact. Styrofoam and geotextile layers are added in vulnerable areas to protect permafrost.

As other coastal communities begin to erode, and other Arctic communities begin to suffer the effects of permafrost loss, the demand for designs that utilize sustainable, recycled/ recovered materials will only increase.

Kadra Branker, P.Eng. and Kenzie Lewis, are members of the Ontario Society of Professional Engineers’ (OSPE) Climate Crisis Task Force. For more information, email: pcetares@ospe.on.ca. (References are available upon request.)

Circuit Riders support water systems and water supply for communities in Northern Manitoba

By Mark Keller

ATAP Infrastructure Management Ltd. (ATAP) assists in operating and maintaining water, wastewater, and municipal infrastructure. A member of the Associated Engineering group of companies, ATAP offers technical support, operations, troubleshooting expertise, and infield and classroom training by highly-experienced operators.

The Government of Manitoba Indigenous Reconciliation and Northern Relations engaged ATAP’s Water System Circuit Riders (WSCR) to provide water systems support to northern communities. It provides operators with tailored water treatment education and hands-on support to improve the efficacy and efficiency of their water system operation and maintenance. The intent is for communities to achieve compliance with facility licensing and meet applicable regulations and environmental acts.

Launched in 2021, the initial phase of the program involved six communities (Duck Bay, Camperville, Berens River, Barrows, Comorant, and Sherridon) and focused on addressing the prolonged boil water advisories ordered in these communities. The WSCR currently supplies water system operational support and water system operator training services to the communities of Berens River, Pikwitonei, Thicket Portage, Wabowden, Cross Lake and Nelson House.

These six communities are all governed by elected mayors and council under the Northern Affairs Act. A collaborative effort, facilitated by the collective expertise of the WSCR team and its extensive network, yielded positive results, enabling five of the communities to independently manage their water systems.

The aim of the WSCR initiative is to enable operators to effectively manage their community water systems and

ensure the availability of clean, fresh drinking water. A strong collaboration between operators, ATAP trainers, and government staff results in the creation of a tailored plan which aids operators in acquiring their certification registration

and prepares them for in-person training specific to their community water systems.

For operators who have already obtained their certifications, the WSCR assist them in developing standard operating procedures to maintain their sys-

Kevin Sutter provides hands-on support during a community visit.

tems and ensure they meet their regulatory and operational requirements. The WSCR travel to these remote communities, providing hands-on mentoring and training for essential operational tasks, such as daily water quality monitoring, sample collection and delivery to laboratories for analysis, equipment maintenance, record-keeping, and reporting.

In 2022, the project entered its second phase, encompassing six communities, including two distant northern communities with challenges, particularly in terms of limited access and resources to address issues concerning their water treatment systems. ATAP successfully secured the contract through a tender process. The communities have struggled to maintain compliance with provincial drinking water requirements and regulations and their water systems have been subject to frequent/long-term water advisories.

Training videos, designed for the transfer of knowledge, were also produced as an integral component of the services offered.

WSCR water and wastewater systems specialists, Phil Beaulac and Kevin

Effective communication with all stakeholders and the participation of northern communities in the program are key components of our ongoing work and successful service delivery.

Sutter, serve as the on-site trainers and are both highly-experienced operators. Beaulac also has numerous years of experience and knowledge gained from working in northern communities.

Sutter says, “two communities are fly-in only, as no other access is available. Due to the remote locations, we stayed with locals.” Beaulac adds, “with the limited access to available materials, we worked with the operators to overcome issues related to the remote-working environments.”

ATAP’s Water Circuit Riders have completed six of nine visits to each community during the 18-month contract. The team members have fostered a mentorship with

the operators and have made themselves available around the clock to offer troubleshooting assistance and leverage their extensive experience in the field of water and wastewater management.

Effective communication with all stakeholders, collaborative efforts with the Government of Manitoba, and the participation of northern communities in the program are key components of their ongoing work and successful service delivery.

Mark Keller is with ATAP Infrastructure Management. Email: kellerm@ae.ca

Centrifuge decanter helps WWTP achieve 30% solids sludge cake

By Robert Rhea

Experiencing a consistently solid cake is just one of the benefits of switching separation technologies for a wastewater treatment plant that serves nearly 50,000 people in Northwest Ohio. The added bonus is a significant cost savings when fewer chemicals are required during the process that included an upgrade from a belt press to a centrifuge decanter.

In just the first two years of operation, the City of Middletown, Ohio Water Reclamation Facility installed a highly efficient decanter that reduced production time by two days a week, increased efficiency, and saves thousands of litres of chemicals per year, translating to substantial cost savings.

The Wastewater Treatment Division of the City of Middletown, Ohio operates and maintains the city’s 100 million litre per day treatment plant. The division protects the health of the community and environment by reclaiming an average of 55 million litres of wastewater each day from all residential, commercial, and industrial sources.

From this process, clean water is discharged into the Great Miami River and approximately 1,200 dry tonnes per year of processed biosolids are applied to farmland for its nutrient and soil conditioning value.

THE CHALLENGE AND SOLUTION

The Water Reclamation Facility previously used a belt press and a centrifuge that wasn’t performing well. In 2018, they removed the belt press because it was difficult for technicians to operate and was only producing 15% to 18% solids. Just two years later, the centrifuge was producing approximately 30% solids, and the efficiency continues.

“We wanted more consistency in our cake solids, resulting in less cost to haul,” said Plant Manager Gerry Burris. “We wanted something to be comparable with the machine we already had, but some-

thing with less mechanical issues, and better service from the manufacturer.”

In 2018, the facility installed a Flottweg Xelletor centrifuge and was able to reduce production time from five days a week to three days a week (8 to 10 hours per day). The older centrifuge was kept as a backup, and the belt press was eliminated.

“With the reduced schedule, we could still move product without the operating cost and the chemical costs of running five days a week,” Burris explained.

“We now operate with better consumption and efficiency than running five days a week, as in the past.”

Burris said they saved a considerable sum of money by installing the machine themselves, which went smoothly. “We had a few startup problems as the operators were trying to mimic the other machine,” he said. “They were accustomed to the controls of the other machine, but integrated the screens and made them similar to what the opera-

tors were familiar with. This made it an easy transition.”

In addition, the more efficient decanter offered the facility an opportunity to make multiple adjustments in the overall operation and reduce its usage of chemicals. In 2016 and 2017, the facility used 270,000 litres of ferric chloride per year. In 2019, it used only 186,000 litres of ferric chloride. In 2020, 163,000 litres were used.

“From the initial startup in 2018 until now in 2024, our cost of chemical usage has decreased from the previous years,” Burris said. “Looking at the data from before the installation of the Flottweg compared to 2023, the average usage of ferric chloride has been consistent with the 2019-2020 usage. Although the cost of ferric has increased by 30%, our budget for chemicals isn’t what it would be without the Flottweg equipment.”

Burris explained that through his experience, the lower the pH the fewer chemicals required. If the pH is in the

The fully automatic adjustment of the bowl speed and differential speeds produces optimum dry matter levels in the dewatered solids at any time, even in case of varying conditions in the feed.

range of 6.0-6.5, they will use roughly 15 litres of ferric chloride for every 3,800 litres of sludge processed.

“We use an autothermal thermophilic aerobic digestion process or ATAD using mixing and high temperature of up to 140°F to eliminate pathogens in the waste stream,” Burris explained. “The waste is then sent through a heat exchanger to cool it down to about 100°F and send it over to the centrifuge. With polymer, it doesn’t dewater as well (due to the high temperatures) so ferric chloride is added at this point of the process. This provides the dewatering enhancement that we need.”

The facility cut the use of ferric chloride in half and the polymer has also been cut significantly.

HOW THE TECHNOLOGY WORKS

Sewage sludge dewatering offers enormous potential savings for the operators of sewage treatment plants. The costs of transport and disposal of the dewatered sewage sludge frequently make up 80% of operating costs. Depending on the capacity of the plant, 1% drier substance in the dewatered sewage sludge can represent cost savings in the five- to six-digit range.

In a traditional centrifuge design, the liquid mixture to be separated is fed through a stationary pipe into the machine. The mixture enters the cylindrical part of the bowl through holes in the scroll body and is then accelerated. Due to centrifugal force, a liquid ring is built inside the machine. The thickness of the ring is called the pond depth. The solids, or heavy phase, form a concentric layer at the bowl wall. The solids are discharged from the machine by the scroll via the conical part. The separated liquids are discharged through a weir at the opposite end.

The cone angle, weir, and scroll body limit the depth of the “liquid pond.” A shallow pond is optimal for dewatering mixtures containing granular solids, whereas as a steeper cone is better for neutrally buoyant materials that need more residence time to separate. The majority of wastewater applications are well suited to deep ponds.

The holes in the body of the scroll, where the liquid mixture is discharged into the centrifuge, have hard facings to increase wear resistance. The geometry of the holes is adapted to ensure a soft entry for the liquid, but shear force is still exerted on the mixture which diminishes the effectiveness of the polymer, and therefore also on separation efficiency.

In case of conventional decanter centrifuges, the body of the scroll limits the pond depth. Thanks to the Xelletor construction, these limits no longer exist. For the first time, the super-deep pond is possible, which has a positive impact on compression, the clarification zone ,and therefore separation efficiency.

A unique centrifuge concept has been developed specifically for high-degree dewatering of sewage sludge. The heart of the new design, the rotor and decanter scroll, were redesigned from the ground up. The result is a scroll with no scroll body.

In this system, the liquid is discharged directly onto the pond in the centrifuge bowl. The liquid is accelerated with far less shear, which results in a reduced consumption of flocculants. The fully automatic adjustment of the bowl speed and differential speeds produces optimum dry matter levels in the dewatered solids at any time, even in case of varying conditions in the feed.

RESULTS

The City of Middletown has been using the Flottweg Xelletor centrifuge since 2018 and has experienced significant cost savings, as well as a favorable 28% to 30% solid cake. With regard to maintenance, it doesn’t require much. After every run, the operators give the bearing end two squirts of grease.

Robert Rhea is with Flottweg Separation Technology Inc. Email: rrhea@flottweg.net

Rotary Lobe Pumps & Macerating Technology for Sludge (Primary, WAS, RAS, Digested, Thickened, etc.), Biosolids, Grease, Sewage, Scum, Lime Slurry, Alum Sludge, Permeate, Polymers, etc.

Lethbridge develops water conservation plan to address declining reservoirs

By ES&E Staff

Alberta relies on melting snow and rain for most of its water. As drought conditions push reservoir levels across southern Alberta to their lowest levels in decades, Lethbridge city council has announced “proactive steps” to address water supply concerns. A resolution passed in a January council meeting suggested that Lethbridge officials explore programs to incentivize water conservation and start monthly updates on the status of drought and water supply conditions.

The city’s Oldman Reservoir dropped to 26% in November 2023 from summer levels of nearly 60%, its lowest levels since it was built in the early 1990s. Meanwhile, the levels in the Saint Mary Reservoir have reached single digits, when they should be over 50%. Waterton Reservoir levels are also significantly

A recent online Water Conservation Plan Survey received some 4,000 responses. Credit: Dmitry Naumov, stock.adobe.com

lower than normal, city officials said.

“While the winter snowfall has been positive in terms of much-needed moisture, we are hoping for significant rainfall in the spring,” said Lethbridge’s General Manager of Water and Wastewater, Doug Kaupp, in a statement.

In November of last year, city staff dredged the water treatment plant intake canal to remove sediment that could limit the intake’s hydraulic capacity, reducing risk of deep freezing under winter’s low flow conditions. Kaupp told reporters at a recent media tour event that expan-

sion plans are in the works to add some 30 million litres of capacity to the water treatment plant, boosting it from 150 million litres to 180 million litres.

Lethbridge is also proactively developing a Water Conservation Plan to help reshape behaviour around water usage. A recent online Water Conservation Plan Survey received some 4,000 responses from local residents and businesses, an all-time high for the Get Involved Lethbridge website. The feedback will be analyzed and help to inform the Water Conservation Plan.

“It is encouraging that an overwhelming majority of respondents indicated they are already aware of potential water shortages, while offering several good conservation ideas,” said Mark Svenson, Lethbridge manager of engineering and environment.

The recent council resolution will see Lethbridge officials continue their collaboration with the province and regional stakeholders to tackle the water shortage. “Our working groups are exploring all options and residents can trust we will keep them informed about our proactive initiatives to manage low water reserves effectively,” announced Lethbridge Director of Infrastructure Services, Joel Sanchez, in a statement.

For more information, email: editor@esemag.com

Mandatory downspout disconnection programs could be a

simple and cost-

effective solution to I/I problems

By Barbara Robinson

Across Canada, there are still millions of residential home roofs connected via downspouts directly into the sanitary sewer system. Starting with Ontario, and working concurrently with the federal government, Norton Engineering has developed an efficient and cost-effective solution to finally get these illegal, outdated connections eliminated.

It became illegal across Ontario to have downspouts connected to the sanitary sewer, following the publication by Ontario’s Ministry of the Environment (MOE – now Ministry of the Environment, Conservation and Parks – MECP) of its first model sewer use bylaw in 1988.

As municipalities adopted the model bylaw (as-is or modified) into individual sewer use bylaws, it became illegal in realcontinued overleaf…

Residential roof downspouts should discharge on the property owner's land, like this one does, and not be connected to a sewer.

time to discharge rain water to the sanitary sewer. Bylaws are in force as soon as they are adopted by a municipality, and these bylaws do not have clauses exempting previous connections (meaning even older connections are now illegal).

Indeed, the first national guideline for existing sewer systems (Developing an Efficient and Cost-Effective I/I Program”, Robinson and Sandink for Standards Council of Canada, 2021) states categorically that a modern inflow/infiltration (I/I) program must address the private side of the sewer system.

Although it is currently illegal, municipalities have been unwilling or unable to enforce their own sewer use bylaws (and many other private side sewer best practices). There is a good reason for this. Sewers, although seemingly simple, are in fact very complex for municipalities to manage.

As shown in Figure 1, different departments at municipalities have jurisdiction over sewers during their lifetime. The bottom two squares represent who has responsibility for sewers, as soon as they receive Final Acceptance from the municipality (subdivision sewers).

Engineering departments have taken the lead on reducing clean water leaking into sewers, but connected downspouts exist on the private side of the property line.

The only staff at a municipality who deal with the private side are operations staff (every time a lateral is blocked, they go out to investigate), and bylaw officers, who enforce (selective) existing bylaws, with very few exceptions.

It is well known that silos existing in municipalities are often virtually unassailable. It can be very difficult to implement change at the municipal level as often times politicians are loathe to introduce policies that voters might resent. These are some of the reasons that the downspout connection issue persists.

But, most importantly, there is no overall guidance or program plan for municipalities – each municipality in Ontario has been attempting to address this individually. We find uptake of existing roof leader disconnection programs to be appallingly low.

ADDRESSING FLOODING IS COMPLEX AT THE PROVINCIAL LEVEL, TOO!

According to the 2022 Ontario Auditor General’s Report, “Value-for-Money Audit: Climate Change Adaptation: Reducing Urban Flood Risk – Office of the Auditor General of Ontario, November 2022”, four primary ministries have responsibility for flood protection in Ontario, which makes it difficult to achieve flood reduction strategies.

It states that, “there is no one government ministry assigned responsibility for co-ordinating measures to address urban flooding in Ontario. Rather, our audit identified four key provincial ministries—the Ministry of the Environment, Conservation and Parks (MECP), the Ministry of Natural Resources and Forestry (MNR), the Ministry of Municipal Affairs and Housing (MMAH), and the Ministry of Infrastructure (IO)—

as having significant responsibilities relating to urban flood management in Ontario.”

The 2022 audit concluded that, “the province does not have effective systems and processes to reduce the risk of urban flooding, nor to provide homeowners, municipalities and other decision-makers the guidance and information they need to reduce their risks of urban floods.”

The Priority 1 Action recommended in this audit is to Increase Public Awareness and Education. It is more specifically recommended that the government work with external parties to share best practices and increase awareness about the increasing risk of flooding.

THE REAL COSTS OF ALLOWING RAINWATER CONNECTED TO THE SANITARY SEWERS

As a professional working on sewers for my entire career, I can tell you that sewers in Ontario respond immediately to rainfall. This is because all of them are still semi-combined, since houses constructed before 1988 legally had foundation drains and downspouts connected to them

The real costs of clean water leaking into our sewers has long been incorrectly calculated by engineers. It has been traditional in engineering to consider only the “chemical and power” costs at the WWTP when calculating the costs of I/I, but this is an inadequate measure of the true cost of I/I and needs to be reconsidered.

Norton Engineering has been advocating for the use of the actual sewer use charges (e.g., $3.15/m3 in Kitchener, 2020) since these represent a direct application of what it costs the municipality to own, operate, maintain, repair and replace the sewer collection and treatment system in its entirety, including fixed and hidden costs.” (Standards Council of Canada 2021, p. 40.)

Firstly, once rainwater enters a sewer system, it becomes, by definition, sewage. We don’t have a “clean water separator” at the headworks of our wastewater treatment plants! When our sewers, trunk sewers and WWTPs are approaching capacity, we plan and finance the necessary upgrades. These upgrades, often a direct result of I/I, are funded directly by municipalities, and/or with financial support from the Ontario and/ or federal governments. This is all taxpayers’ money, even if “municipal accounting” does not account for this.

Next, clean water in sewers (I/I) is the proximate cause of sewage backup and flooding, bypasses, and combined sewer overflows to the receivers. When a municipality experiences a

substantial flooding event, staff and senior management may be occupied with the fallout for many years, at great cost to taxpayers, since staff are not available to continue with normal duties.

Insurers and residents incur enormous costs associated with flooding. Insurance rates are climbing across Canada, and many residents find, to their dismay, that their coverage is either inadequate or non-existent (becoming ‘uninsured losses’).

While the above costs are impossible to estimate (many are long-term), an excellent proxy for the entirety of (just the municipal) costs is what municipalities are charging residents for sewer services (typically about $3.25/m3, and constantly climbing). This number is actually insufficient to capture the real costs to taxpayers, but it’s a start.

ESTIMATED YEARLY COST IN ONTARIO OF CONNECTED DOWNSPOUTS

Norton Engineering estimates that there are at least a million downspouts connected to sanitary sewers in Ontario (assuming 3.75 million existing homes, of which, 90.5% are serviced by sewer systems, or about 3.4 million homes). About two-thirds of homes were built before the Model Sewer Use By-law was published in 1988.

That’s 2.3 million homes. And if we assume that half of these homes still have downspouts connected to the sanitary sewer, that’s over one million homes connected to sanitary sewer systems. Table 1 summarizes the cost of treatment and bypass alone of allowing these illegal connections to persist. These costs do not include any of the other costs associated with clean water discharging into sewers, as detailed above. continued overleaf…

Table 1: Estimated Cost of Treatment and Overflows Only, Ontario, per Year

Figure 1

MUNICIPALITIES CAN BE, AND ARE, PROACTIVE IN PROTECTING THE PUBLIC IN OTHER WAYS

Municipalities already take proactive action on the private side to protect the health and safety of their residents. Where I live in Kitchener, I got a letter saying my gas meter was due for replacement and that I should make an appointment.

While the gas fitter was on site, he also inspected the rest of the gas infrastructure (completely unrelated to the meter), and determined that my exterior piping was unpainted, in contravention of the current Code (CAN/CSA-B149.1-10, section 6.16.1.) I was then sent a formal letter advising me that I would be issued a non-compliance infraction notice for corrective action if a follow-up inspection found it to be uncorrected.

Of course, gas infrastructure in poor condition puts residents, and perhaps their neighbours at risk. So do connected downspouts – a substantial cause of routine basement flooding, which is a health hazard. They cause personal and financial stress for residents directly involved.

PUBLIC EDUCATION IS THE KEY

There is a simple solution to this dilemma. As stated above, homeowners, municipalities and other decision-makers need help. Ontario has been encouraged by the Auditor General to take leadership on reducing the risks of urban flooding.

Norton Engineering has been educating the general public (through public lectures, radio, television, and print articles) for nearly a decade, and taking and answering hundreds of questions. Although residents are generally aware that downspouts should be disconnected, they don’t understand why. This lack of understanding why this is essential has resulted in very poor uptake of existing efforts by municipalities.

Norton’s messaging to residents, developed over many years in response to questions from residents, includes the following:

• Having your own downspout connected to the sanitary sewer increases your own risk of flooding.

• Having your downspout connected increases the risk of

flood for your neighbours and perhaps neighbourhood. If the hydraulic grade line in the sewer is just at flood level, and you introduce a lot of water in a hurry, flooding will occur.

• Every connected roof (assuming all downspouts) costs about $2,000 per year (depending on rainfall) to treat, and all residents pay for this!

• Climate change is here, and we all have a responsibility to do what we can to mitigate the risks. This solution is simple, and we can all do it easily. Let’s make it socially unacceptable to have connected downspouts.

• Overflows to receivers, expansion of wastewater plants, and development freezes (impediments to new housing) are all vastly improved by this simple practice.

Once residents understand this, they become more than willing to comply. Norton receives many, many comments from listeners about the wisdom and necessity of implementing this best practice. Public education (on TV, radio, newspapers, etc., not just bill inserts or website information) relieves municipalities from having to “force” residents to disconnect.

Norton Engineering is calling on the provinces (starting with Ontario) to develop the appropriate program, messaging, media coverage, and incentives for municipalities to implement at the same time, with appropriate consequences if municipalities do not comply (e.g., stop issuing environmental certificates of approval and disallowing WWTP expansions to non-compliant municipalities).

This can be achieved in short order, particularly if the government follows the Auditor General’s recommendation to work with external parties to share best practices and increase awareness of flooding. The residents of Ontario are ready and willing to disconnect their downspouts to protect their own property and for the good of society. What are we waiting for?

Barbara Robinson is with Norton Engineering Inc. For more information, email: nortonengineeringinc@gmail.com

SEWER FLOW MONITORING

ACG-Envirocan Inc. offers innovative solutions for sanitary, storm and combined sewer flow monitoring. Our RadarSens technology enables cost-effective level measurement to measure flow to reduce the frequency and impact of pollution overflow events. With permanent installations of remote monitoring equipment, our system ensures timely alerts for operations, pinpointing immediate problem sites.

ACG-Envirocan Inc.

T: 905-856-1414

E: sales@acg-envirocan.ca

W: www.acg-envirocan.ca

AFTER-SALES SERVICE

Discover AERZEN’s comprehensive after-sales services. From technical support to repairs, original AERZEN parts, and planned maintenance, we ensure your equipment’s longevity. Connect with our after-sales service team for expert advice and on-site visits. With over 160 years of expertise for lasting efficiency, contact us today to maximize your AERZEN packages.

AERZEN Canada Inc.

T East: 450-424-3966

T Central: 437-703-7630

T West: 587-316-0155

E: service-ca@aerzen.com

W: www.aerzen.com/canada

BLOWER AND COMPRESSOR TECHNOLOGY IN ONE SYSTEM

Combining experience with innovation, AERZEN's Delta Hybrid ingeniously merges 160 years of blower design expertise and 80 years of screw compressor technology. Operating at up to 1,500 mbar, it efficiently caters to diverse needs, ensuring cost efficiency, reduced maintenance, and expanded versatility— all while prioritizing energy efficiency. This revolutionary assembly seamlessly blends expertise and cutting-edge technology for optimal performance.

AERZEN Canada Inc.

T East: 450-424-3966

T Central: 437-703-7630

T West: 587-316-0155

E: sales-ca@aerzen.com

W: www.aerzen.com/canada

CHEMICAL AND CORROSION RESISTANT DUCT SYSTEM

Asahi/America’s Pro-Vent® piping is specifically designed and manufactured for ventilation and exhaust systems that transport corrosive fumes. It is superior in performance to PVC, fiberglass and sheet metal systems due to its chemical resistance, mechanical properties, solid construction, and ease of installation. It is perfect for applications such as water treatment facilities, electroplating shops, semiconductor wet stations, and pharmaceutical processing.

Asahi/America

T: 800-343-3618

F: 800-787-6861

E: asahi@asahi-america.com

W: www.asahi-america.com

ALL INCLUSIVE, HIGH VOLUME CHEMICAL FEED

The FLEXFLO M5 is a fully enclosed and easily configurable, high volume dosing pump that does not require external control devices to operate. M5 features a large 5” display for easy viewing with intuitive touchscreen controls. The remote signal options include Pulse, 4-20mA, Modbus TCP, EtherNet/IP™, and PROFIBUS for enhanced supervision and automation for critical metering applications.

Blue-White Industries

T: 714-893-8529

F: 714-894-9492

E: info@blue-white.com

W: www.blue-white.com

ENGINEERED SKID SYSTEMS

CHEM-FEED engineered skid systems are simple to operate, easy to order, and include everything needed for precise chemical feed. Say good-bye to leaky plumbing causing hazardous work environments with leak free threadless connections. Blue-White’s® lightweight, chemical and UV resistant, polyethylene triple skids ship fully assembled to save installation time, include a built-in drip container, wall/floor mounting brackets, and a visual flow indicator.

Blue-White Industries

T: 714-893-8529

F: 714-894-9492

E: info@blue-white.com

W: www.blue-white.com

LIFT STATION GRINDER

Boerger’s M2 Multicrusher twin shaft grinder, is suitable for lift stations and can be customized with channel frames for varying heights. It offers capacities ranging from 50 – 2,000 gallons per minute and can effectively process materials such as rags, rocks, wood, wipes, and more.

Boerger, LLC

T: 612-435-7300

E: america@boerger.com

ELECTRIC ACTUATORS

Chemline’s V Series actuators are CSA approved and have all the important features for municipal applications: hand wheel manual override, mechanical travel stops, position feedback and available control station and bluetooth module for remote operation, programming and reporting of actuator diagnostics. They are lightweight, compact and corrosion resistant, ideal for Chemline plastic valves, ball to 6" and butterfly up to 20".

Chemline Plastics Ltd.

T: 800-930-CHEM (2436)

E: request@chemline.com

W: www.chemline.com

CARBON BLOCK CARTRIDGES

Harmsco offers the industry’s largest Carbon Block Cartridges – with the greatest throughput per cartridge. The dual-stage cartridge features a solid activated carbon block, followed by 5-micron nominal pre-filtration to reduce taste, odour and chlorine, as well as PFOS/PFOA. Harmsco’s activated carbon technology was selected as a finalist in The Water Council’s Fall 2023 Tech Challenge for PFAS remediation. Harmsco Filtration Products

T: 800-327-3248

F: 561-845-2474

E: sales@harmsco.com

W: www.harmsco.com

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

STORMWATER QUALITY TREATMENT

Inspection and maintenance are fundamental to the long-term performance of any stormwater quality treatment device. The Stormceptor EF/EFO design makes inspections and maintenance an easy and inexpensive process conducted at grade. Once serviced, the Stormceptor EF/EFO is functionally restored as designed, with full pollutant capture capacity. Learn more at: www.imbriumsystems.com

Imbrium Systems

T: 800-565-4801

E: info@imbriumsystems.com

W: www.imbriumsystems.com

SOLUTION FOR ODOUR AND CORROSION CONTROL

The IPEX Vortex Flow™ Insert (VFI) is a revolutionary technology for eliminating odorous emissions and minimizing corrosion in vertical sewer drops. With no moving parts and requiring no maintenance, VFIs have delivered significant cost savings in installations for municipalities across North America.

IPEX

T: 866-473-9462

W: www.ipexna.com

PVC PRESSURE PIPE SYSTEM

IPEX TerraBrute® CR is now available in an industry leading range of 4” to 24” sizes. Engineered for horizontal directional drilling (HDD) and other trenchless applications, it is a 100% non-metallic, AWWA C900 PVC pressure pipe system. Non-corroding and installation friendly, TerraBrute CR allows you to standardize on PVC throughout your potable water and sewer infrastructure.

IPEX

T: 866-473-9462

W: www.ipexna.com

DAVIT CRANE WHEEL BASE

Revolutionize your lifting operations with the OZ Wheel Base. This versatile base effortlessly transports and positions your OZ davit crane (up to 1,200 lbs) across diverse environments. Its steel construction and powder-coat finish ensure lasting durability, while oversized rear swivel casters and a patent-pending floor-anchoring system guarantee smooth mobility and secure 360° rotation, even under load.

OZ Lifting Products

T: 507-474-6250/800-749-1064

E: sales@ozliftingproducts.com

W: www.ozliftingproducts.com

WATERTIGHT DOORS

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, Inc.

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, Inc.

T: 647-923-8244

E: aron@proaquasales.com

W: www.proaquasales.com

VERTICAL THERMOPLASTIC SUMP PUMPS

Vanton’s vertical thermoplastic sump pumps are engineered for the dependable handling of corrosive, abrasive, and ultra-pure process fluids, plant effluents and wastewater, over broad temperature and pH ranges. Available in polypropylene, PVC, CPVC, or PVDF, these rugged pumps are widely used across various manufacturing industries and water treatment facilities. Every Vanton pump is performance tested to the specified service condition intended.

Vanton Pump & Equipment Corporation

T: 908-688-4216

F: 908-686-9314

E: mkt@vanton.com

W: www.vanton.com

VERTICAL SUMP PUMP WITH RUN-DRY CAPABILITY

Vanton cantilevered vertical thermoplastic SGK pumps are engineered for the dependable handling of corrosive process fluids, plant effluents and wastewater, over broad pH ranges. Available in polypropylene, PVC, CPVC or PVDF, these rugged pumps are widely used across various manufacturing industries and water treatment facilities. Every Vanton pump is performance tested to the specified service condition intended.

Vanton Pump & Equipment Corporation

T: 908-688-4216

F: 908-686-9314

E: mkt@vanton.com

W: www.vanton.com

How to identify excessive sludge accumulation in wastewater lagoons

By Patrick Taylor

Many wastewater lagoons eventually face excessive sludge accumulation. This buildup can significantly impact the treatment process, causing several operational issues such as odours and elevated levels of BOD, TSS, and ammonia in the effluent. Here are the most common signs of excessive sludge accumulation and a simple approach to maintain optimal system efficiency and effluent quality.

VISIBLE SIGNS AND ODOUR

In some cases, sludge is visually apparent, with sludge islands floating on the lagoon’s surface or mounds rising above the water level. This exposed sludge can release methane or hydrogen sulfide gas, resulting in foul odours and complaints from nearby residents. Observing such phenomena means sludge should be addressed promptly.

TURBIDITY AND EFFLUENT QUALITY

Monitoring the lagoon through regular influent and effluent sampling is crucial for detecting sludge-related problems. High turbidity, poor nutrient removal, and changes in colour often indicate sludge accumulation. Sludge particles may also contaminate the effluent, reducing its clarity and leading to abnormally high or non-compliant total suspended solids (TSS) measurements.

STORAGE CAPACITY, NUTRIENT REMOVAL, AND ALGAE BLOOMS

As sludge accumulation increases, a lagoon’s storage capacity and retention time decreases. This can impede the lagoon’s ability to effectively remove nutrients, which can cause problems such as algae blooms or exceedances in regulated discharge limits.

SHORT-CIRCUITING AND WASHOUT

Excessive sludge accumulation can create channels within the lagoon, causing wastewater to bypass the intended

Sludge removal and dewatering with the Bishop Solids Management Solution offers a costeffective, fast, and energy efficient alternative.

The consequences of overlooking wastewater lagoon maintenance are unmistakable, manifesting in reduced sludge storage, compromised effluent quality, persistent odours, and other issues.

treatment process. This flow short-circuiting results in reduced retention time and compromises treatment performance. If a lagoon also experiences high hydraulic loading, such as a storm event, the high flow and short retention time can cause washout of a significant portion of the microbial population. It can take days, weeks or longer for the biological process to recover, significantly impacting lagoon performance.

BENTHAL FEEDBACK IN NON-AERATED LAGOONS

Non-aerated lagoons can experience a phenomenon known as benthal feedback, particularly during the spring season. As the water warms, turbulence stirs up the sludge blanket, releasing accumulated hydrogen sulfide and nutrients. In severe cases, the concentrations of certain wastewater constituents can become higher in the effluent than in the influent, indicating a significant sludge-related issue.

OPERATOR ACCESS AND MAINTENANCE CHALLENGES

Excessive sludge can hinder operator access to critical components that require regular maintenance. Aeration systems, inlet structures, force mains, and other essential equipment may become blocked or inaccessible due to sludge accumulation. This obstruction can compromise routine maintenance and hinder the efficient operation of the lagoon.

FAST AND AFFORDABLE REMEDIATION OPTIONS

Regular maintenance, including timely sludge removal, is key to ensuring the long-term effectiveness of lagoon systems. Bishop Water provides comprehensive services to remove and dewater sludge from wastewater treatment lagoons of all sizes. Depending on the situation, urgency and budget availability, a total cleanout might be the right approach, or a partial cleanout to remove sludge only from areas of concern and defer the full cost to a future fiscal year.

Once a plan is ready, sludge removal equipment is brought in. Bishop’s process provides a simple and cost-effective way to collect, dewater and contain

sludge and achieves a high level of dry solids using only polymer conditioning, Geotube™ containers and gravity.

Compared to alternative methods, the Bishop Solids Management Solution is less complex, more energy efficient and can collect and dewater sludge at a

significantly higher rate, which means projects can be completed faster and more affordably.

Patrick Taylor is with Bishop Water Technologies. Email: patrick@bishopwater.ca

Microalgae strains capture phosphorus from wastewater for reuse

By ES&E Staff

Colorado-based National Renewable Energy Laboratory (NREL) researchers have identified and isolated phosphorus-hyperaccumulating algae that have the potential to capture and reuse phosphorus from wastewater before it can be discharged and cause imbalances such as harmful algal blooms in aquatic ecosystems.

The revolving algal biofilm (RAB) system by Gross-Wen Technologies is an emerging technology for phosphorus removal from wastewater, that maximizes the ability of algae to harness solar energy, and efficiently accumulate and remove the vital nutrient, storing it inside the cell as polyphosphate, a new study says.

“In the RAB system, phosphorus-laden algae are cultivated in wastewater attached to a revolving belt,” a NREL announcement explained about the project. “The grown algal biomass can then be harvested from the belt and dried for use as agricultural fertilizer or as feedstock for the manufacture of biofuels and bioproducts. This process can help close the phosphorus-cycle loop by recycling and reusing the phosphorus in wastewater, decreasing demand on limited minable phosphorus resources.”

Among 101 microalgae strains identified by NREL researchers, seven possessed high levels of polyphosphate. These seven isolated algal strains possessed at least 50% more polyphosphate by cell dry weight compared to a baseline RAB system algal community, which came in at 5.1% polyphosphate by cell dry weight, the study found. The strains included 82 green algae, 9 diatoms, and 10 cyanobacteria.

The RAB process can not only help prevent harmful algal blooms in aquatic ecosystems but can also create a closedlooped cycle for phosphorus. In addition to phosphorus recovery, the results

A close-up of algal biofilm on a RAB system. Photo courtesy of Gross-Wen Technologies

from this research may have additional benefits for the recovery and reuse of other valuable resources lost in wastewater, announced NREL researchers.

“The beauty of this research into phosphorus-hyperaccumulating algae is its implication beyond just phosphorus recovery,” announced Jianping Yu, principal investigator at NREL and senior author of the study, in a statement. “Polyphosphate is known to bind to and accumulate metals in algae. So, the strains isolated in this study may be promising for other algal waste-remediation applications, like removing or recovering harmful or valuable metals from industrial processes and wastewater.”

Eric Schaedig, NREL researcher and lead author of the study, said he was curious to know which of the algae species living in the RAB systems were doing the “heaviest lifting” for removing the phosphorus from wastewater.

“From a biological perspective,” he said, “if we can isolate and enrich RAB systems with these hardworking algal species, it would boost the efficiency of the overall system and help us close the loop on the phosphorus cycle.”

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