WCW26

Wastewater siphons represent some of the most difficult municipal assets to assess due to complex hydraulics, limited access, and operational constraints that restrict traditional inspection methods. This presentation examines the application of free-swimming multi-sensor inspection technology (INGU Pipers®) as a rapid screening tool for evaluating the condition and performance of large, multi-barrel wastewater siphons, using the City of Lethbridge triple barrel siphon as a detailed case study.
The Lethbridge system consists of multiple asbestos cement barrels operating under gravity-driven and pressurized conditions. Screening was conducted to establish a baseline understanding of system integrity, identify hydraulic inefficiencies, and inform future maintenance and high-resolution condition assessment planning. The inspection collected hydraulic grade line data, acoustic leak detection, air pocket identification, and indicators of internal restrictions while the system remained fully operational.
Results confirmed no active leaks within tool sensitivity, while identifying localized air accumulation and segments exhibiting elevated hydraulic losses consistent with internal deposition and reduced conveyance efficiency. Screening data supported targeted recommendations including progressive pigging to restore hydraulic performance and follow-up structural assessment to better understand long-term asset integrity.
This case study demonstrates how minimally invasive screening enables utilities to evaluate complex siphon infrastructure quickly, reduce uncertainty, and make defensible decisions regarding maintenance and capital planning. Attendees will gain practical insight into deployment strategies, data interpretation, and how screening technologies can support phased, risk-based condition assessment programs for critical wastewater siphons.

In Winnipeg, Manitoba, industries discharging industrial wastewater to the municipal collection system are required to meet wastewater quality limits set forth by the City’s Sewer By-law No. 106/2018. Given the strict discharge limits for biological oxygen demand (BOD), total suspended solids (TSS), pH, and fats, oils and grease (FOGs), many industries utilize onsite wastewater treatment systems to reduce these parameters prior to discharging their wastewater to avoid costly surcharges. However, for industries that produce a variety of different products, such as large-scale food processing facilities, the resulting wastewater quality can be highly variable making it difficult for onsite wastewater treatment systems to maintain optimal treatment conditions, such as coagulant dose. Therefore, industries are burdened with needing to continually monitor and manually adjust their onsite wastewater treatment system in order to minimize the discharge of overstrength wastewater and avoid surcharges. Given that most industries do not have dedicated wastewater treatment system operators, the onsite wastewater system often goes unattended and operates outside of the optimal treatment conditions, particularly when the industry produces highly variable wastewater quality.
To better control their onsite wastewater treatment system, a large-scale food processing facility installed a real-time monitoring system (i.e., an S::CAN Monitoring Station) to continually measure water quality prior to and following the onsite dissolved air flotation (DAF) system and automatically adjust coagulant and polymer dosing to meet treated water targets. The S::CAN system consisted of two (2) online UV-Vis spectrophotometers that would measure BOD, TSS, and FOGs as well as ORP and pH meters to monitor pre and post-treated water quality. Initially, the pre and post-treated water quality was monitored for approximately 3 months to evaluate the variability in the incoming wastewater quality and to identify periods where the production of a particular food product resulted in wastewater that was difficult to treat using DAF at the set coagulant and polymer dose. For production periods identified as producing wastewater that was particularly challenging for the DAF to treat, jar-testing was used to determine the optimal coagulant and polymer dose. Following the initial evaluation and optimization period, the wastewater quality data and optimal chemical dose ranges were used to develop and refine feedback logic used to control the chemical delivery system.
Overall, the implementation of the real-time S::CAN monitoring and automated dosing control system enabled the facility to transition from reactive, manual process adjustments to a proactive, data-driven treatment approach. By continuously characterizing influent variability and linking water quality measurements to optimized coagulant and polymer dosing strategies, the facility improved the stability and performance of its DAF system despite highly variable production schedules. The project demonstrates that integrating real-time monitoring with adaptive control logic can significantly enhance onsite industrial wastewater treatment reliability, particularly for food processing facilities with fluctuating wastewater characteristics.

Leduc County completed a comprehensive condition assessment of the New Sarepta Forcemain and the LS‑1 Forcemain to support proactive asset management and risk‑based decision‑making for critical wastewater infrastructure. The New Sarepta Forcemain is a 200‑millimetre PVC pipeline owned and operated by Leduc County and serves as a vital component of the regional wastewater system. The LS‑1 Forcemain is a 300‑millimetre PVC pipeline owned by Edmonton International Airport and operated by Leduc County, where reliable wastewater conveyance and early leak detection are critical to airport operations and environmental protection.
The assessment incorporated acoustic leak and gas pocket detection, transient pressure monitoring, hydrogen sulfide (H₂S) monitoring, and fatigue analysis of the PVC pipelines. This integrated methodology enabled a robust evaluation of key operational risks, including leakage, entrapped air, pressure surges, corrosive environments, and long‑term material fatigue.
The findings demonstrated that comprehensive condition assessments significantly enhance confidence in pipeline condition, support lifecycle planning, and inform risk‑based maintenance and capital investment strategies. This case study underscores the value of integrated assessment approaches in improving system resilience and reliability, capturing lessons learned, identifying opportunities for future enhancement, and supporting the long‑term management of critical wastewater assets.
 

To address persistent odour concerns at the discharge of the City of Saskatoon Jasper Avenue Lift Station, an Oxygen Injection System was installed to proactively reduce hydrogen sulfide (H₂S) formation within the force main. The system uses pressure swing absorption to concentrates oxygen on site from atmospheric air and injects the oxygen into the wastewater stream, maintaining aerobic conditions and preventing the biological generation of H₂S as the wastewater is pumped through the discharge forcemain.
Since commissioning, the system has achieved over a 90% reduction in H₂S concentrations at the downstream manhole. This significant decrease has improved odour control, reduced corrosion potential within the collection system, and enhanced overall system performance without the need for chemical addition.
The installation demonstrates an effective, sustainable approach to odour management through in-line oxygenation and proactive sulfide prevention.