Signalized Sl-Rat Inspection

Waterloo, Ontario Adapts to New Regulatory Framework for Sewer Systems

SL-RAT Signalized at an intersection in Waterloo, Ontario.
An SL-RAT setup at an intersection in Waterloo, Ontario. Sound waves travel over 200 ft between manholes, with each measurement taking an average of 90 seconds.

Using innovative technologies, Waterloo, Ontario, adapts to provincial regulatory changes for wastewater collections and stormwater management systems.

Background

In 2023, the Ministry of the Environment, Conservation and Parks (MECP) in Ontario introduced the Consolidated Linear Infrastructure Environmental Compliance Approvals regulatory framework (CLI-ECA) to modernize how the province manages municipal wastewater collections and stormwater management systems.

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This change aimed to streamline processes for municipalities while maintaining high environmental standards. The CLI-ECA grants municipalities and prescribed developers preauthorization on certain infrastructure projects, provided specific conditions are met.

This flexibility simplifies processes, but comes with stricter requirements for monitoring system performance, inspecting and maintaining infrastructure, and reporting overflows or spills. This balance of flexibility and accountability fosters an environment that encourages innovation and the adoption of advanced tools and strategies.

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Responsible for more than 260 miles of small-diameter — less than 24-in. — sanitary gravity sewers, the City of Waterloo has implemented a condition-based maintenance program to optimize its sewer management. Traditionally, most municipalities use a time-based or rotational maintenance program that cleans all assets on a fixed schedule.

These time-based programs range from a one-year to a 12-year cycle depending on the utility with a five-year cycle being most common. These programs also sometimes include a “trouble spot” or hot spot cleaning program with shorter cycles overlayed on top. In contrast, condition-based programs assess the health of assets before making maintenance decisions.

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Transitioning to a condition-based maintenance program requires reallocating resources. While this can sometimes stall any change, the CLI-ECA’s requirements for documented inspections and maintenance have inspired municipalities to consider new approaches.

Waterloo Embraces Condition-Based Maintenance

Waterloo partnered with Rapid Assessment Technology Services Inc. (RATS Inc.) to deploy the Sewer Line Rapid Assessment Tool (SL-RAT).

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The SL-RAT uses transmissive acoustics to assess pipe blockage conditions between maintenance holes. Its transmitter and receiver components are placed on adjacent maintenance holes. The transmitter sends a series of tones through the pipe and the receiver listens for the known signal. The receiver then assigns a score from 0 (fully obstructed) to 10 (significant excess flow capacity).

RATS Inc. Promo
RATs Inc, based in Vaughan, Ontario, uses acoustic inspection to inspect more than 4,000 m of gravity sewer lines per day.

The simplicity and inspection speed of the SL-RAT make it an ideal tool for municipalities, like Waterloo, who are transitioning to a condition-based maintenance. The device requires no flow contact or confined space entry, enabling RATS Inc.’s two-person crew to inspect more than 2.5 miles per day.

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RATS Inc., headquartered in Vaughan, Ontario, is the provider of this service across the province. Their expertise allows municipalities like Waterloo to integrate technology effectively into their workflows.

As Anthony Abbruscato, Partner (RATS Inc.), describes, “Our goal is to help municipalities across the province transition from a time-based sewer maintenance practice over to a condition-based one by leveraging innovative technology. By facilitating this, utility owners can fully optimize the workflow for their wastewater collection systems, allowing for system resiliency through enhanced cleaning and inspection scheduling, while demonstrating to the MECP (regulators) a robust sewer operations and maintenance program under the CLI-ECA.”

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Early Success

The full program with Waterloo will span three years, aiming to benchmark their entire gravity sewer system. In the first year alone, RATS Inc. inspected approximately 110 miles of sewer lines, identifying areas for targeted maintenance. Alongside acoustic inspections, RATS Inc. also facilitated a maintenance hole inspection program. On average, an SL-RAT crew will open 30 to 50 maintenance holes per workday. By recording this additional high-level condition information, Waterloo will gain additional insights into their system health.

The results from the first year demonstrate the program’s success. Of approximately 2,800 pipes inspected, only 5 percent required further maintenance. Given that cleaning gravity sewer pipes can cost upwards of $5CAD per meter, any potential reduction in cleaning yields significant direct and indirect cost savings.

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The shift to condition-based maintenance also brings significant environmental advantages. For instance, the program is estimated to have conserved over two million litres of flushing water. Avoiding unnecessary cleaning further reduced energy consumption associated with running flushing trucks, lowering greenhouse gas emissions tied to maintenance activities.

Additionally, reduced wear and tear on equipment, like cleaning trucks, not only extends their lifespan but also decreases long-term capital expenditures and operational costs.

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Finally, proactively addressing problematic pipes across a broader swath of the network also significantly reduces the risk of sanitary sewer overflows (SSOs) and basement backups.

Histogram of Waterloo, Ontario's inspection data.
Histogram of Waterloo’s inspection data showing pipe scores: 7-10 classified as ‘Good,’ 4-6 as ‘Fair,’ 1-3 as ‘Poor,’ and 0 as ‘Blocked.

Moreover, the CLI-ECA emphasis on record-keeping and regular monitoring ensures that municipalities like Waterloo maintain consistent oversight of their systems. The data collected through this program can identify trends in system health, enabling better long-term planning, capital improvement planning, and resource allocation. This proactive approach ensures that municipalities remain resilient in the face of evolving regulatory and environmental challenges.

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Future Goals

At its core, Ontario’s CLI-ECA aims to increase flexibility while upholding high standards for system performance and environmental protection.

“The SL-RAT technology allowed Waterloo to enhance operational knowledge of the sanitary sewer network, meet new CLI-ECA regulatory obligations, inform on a risk-based CCTV inspection and repair program, and will allow us to optimize our operational budget to address risk,” says Leigh McDermott, director city utilities at the City of Waterloo.

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By leveraging innovative technology like the SL-RAT, Waterloo has not only met regulatory requirements but has also achieved measurable benefits. Waterloo’s condition-based maintenance program has reduced costs, conserved water, minimized environmental risks, and allowed for smarter resource allocation.

Waterloo’s proactive and data-driven approach stands as a model for municipalities across Ontario, proving that modern regulations can inspire practical innovations.

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By aligning regulatory compliance with advanced technology and sustainability goals, the City of Waterloo demonstrates how thoughtful adaptation to new frameworks can deliver lasting benefits for both communities and the environment.

Chase Mendell is the marketing and system operations manager at InfoSense. Anthony Abbruscato, is a partner at RATS Inc.

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