Wastewater disinfection is essential for protecting public health and downstream water quality, but conventional control approaches such as flow-pacing struggle to reflect real-world operating conditions. In practice, disinfectant demand varies with changes in hydraulics, water quality, and operational conditions, which are not fully captured by flow alone. This can lead to inefficient dosing, unnecessary chemical use, and inconsistent treatment performance.
OaSys iCT™, a model-based intelligent control system for disinfection, reflects a shift in municipal disinfection from fixed chemical dosing toward model-based control that improves performance while reducing chemical use and operational variability. Developed by USP Technologies, the system evolved from academic research into applied municipal deployment, with Ontario serving as the primary environment where the technology was tested, validated, and refined.
The origins of the system trace back to foundational disinfection research led by Domenico Santoro, Director, Research and Innovation at USP Technologies, during his doctoral work and subsequent industry roles. His research focused on optimizing chemical disinfection through improved understanding of process kinetics and system variability. This work evolved into an algorithmic control approach designed to adjust dosing dynamically based on real-time conditions rather than fixed assumptions.
Early development involved collaboration between academia and industry, including work at Trojan Technologies, a sister company to USP Technologies, where initial testing helped shape the direction of the technology. This work was supported through Ontario Water Consortium (OWC)’s Advancing Water Technologies Program, through which Trojan Technologies and Western University collaborated on a water reuse research project that included applied testing. Over time, this evolved into OaSys iCT™, a system designed to improve both consistency and efficiency in municipal disinfection.
Ontario played a central role in moving the technology from concept to validated system. A full-scale demonstration at the North Toronto Wastewater Treatment Plant, supported by Toronto Water and delivered in collaboration with Trojan Technologies provided one of the earliest validations of the approach at scale. This work provided critical real-world validation under full-scale operating conditions and helped establish confidence in system performance across variable wastewater environments.
Additional validation occurred at the Greenway Wastewater Research Facility in London, where pilot-scale systems supported algorithm development using continuous real wastewater conditions. As Eunkyung Jang, Research Engineer at USP Technologies, explained, “without this type of demonstration and pilot trial, we wouldn’t be able to reach this stage of technology development, especially given how important it is to work under real operating conditions.”
Supporting work from academic and applied research partners further strengthened the technical foundation. At the University of Toronto, Dr. Yuri Lawryshyn worked on process modelling and cost analysis tools to quantify performance and operational savings. The Lambton Water Centre contributed bench-scale testing to evaluate disinfectant demand and decay across different wastewater conditions. These efforts reflect OWC’s collaborative academic–industry network within Ontario’s water innovation ecosystem and its role in advancing and validating new technologies.
Building on this foundation, subsequent work helped refine system behaviour under realistic hydraulic and water quality variability. A later study with the Region of Peel used the OaSys iCT Echo™ platform to compare disinfectant strategies under controlled conditions, further supporting confidence in the system’s performance.
Across these projects, Ontario provided more than testing sites. It offered infrastructure, technical expertise, and a collaborative research environment that enabled continuous refinement. Contributions from Mitacs-supported researchers, postdoctoral fellows, municipal operators, and academic partners created a sustained feedback loop between research and practice.
Commercialization and Technical Performance
Traditional flow-pacing applies a fixed disinfectant dose proportional to flow but does not account for the underlying factors that govern disinfection performance. OaSys iCT™ addresses this by using a model-based control framework that integrates hydraulics, chlorine demand, decay, and disinfection kinetics to calculate the optimal dose required to achieve a target CT value (disinfection performance requirement).
At the core of this approach is a detailed characterization of the contact basin, supported by computational fluid dynamics modeling and site-specific measurements of chlorine demand and decay. This allows the system to continuously adjust dosing in response to real-time conditions, rather than relying on static assumptions.
In controlled studies, this approach demonstrated substantial improvements in both efficiency and stability. Compared with conventional flow-pacing methods, OaSys iCT™ reduced hypochlorite use by up to approximately 50 percent while maintaining or improving disinfection performance. At the same time, variability in microbial indicators was significantly reduced, with more consistent achievement of target effluent quality.
These improvements translate directly into operational benefits, including lower chemical consumption, more stable residuals, and reduced downstream dechlorination requirements.
As Ian Watson, Technology Development Manager at USP Technologies, explained, “when you’re trying to bring something new to the municipal wastewater market, the first question is always: where has this been proven before?”
That requirement for demonstrated performance shaped the commercialization pathway and reinforced the importance of Ontario-based pilots in establishing credibility.
The system is deployed through multiple formats, including in-channel control systems and a simulation-based platform known as OaSys iCT Echo™. Echo allows utilities to evaluate control strategies in a low-risk environment before full deployment, supporting confidence in adoption decisions.
Field experience has also informed refinement. Watson noted that implementation details such as sensor placement and hydraulic signal timing can significantly affect system performance due to transport delays within treatment processes. He also observed that many facilities operate with more variability and inefficiency than they recognize, creating significant opportunities for optimization.
The system delivers the greatest value in facilities with high variability in flow or water quality, particularly those with high chemical disinfection or dechlorination costs, or systems impacted by combined sewer overflow events.
Outlook and Ecosystem Impact
Future development is focused on combined sewer overflow (CSO)-driven applications and improving performance under highly variable, episodic conditions, which remain among the most complex challenges in municipal disinfection.
What emerges from this work is not only a technical system but also a demonstration of how Ontario enables applied research at scale through a highly collaborative water sector. The combination of municipal infrastructure, academic expertise, and industry collaboration created the conditions for sustained development over many years.
Reflecting on this environment, Watson emphasized the strength of OWC in enabling Ontario’s water innovation ecosystem and its role in supporting applied water innovation, noting the close integration between utilities, researchers, and industry partners and how that sustained interaction has been critical in moving technologies from early-stage concepts into real-world deployment, adding:
“There is just not a better place in North America to do wastewater treatment research than in Ontario, given how closely industry and research teams are able to work together.”