Helping citizens help the environment — that’s what the city of Victoria, British Columbia, has in mind as it looks toward a new incentivized program for private-side inflow and infiltration mitigation.

The city has a longstanding asset renewal program to address sewer issues on the public side, including I&I, and in recent years has implemented additional grant-funded projects. But increasing public awareness about I&I and assisting residents with lateral repairs will mark a new territory for officials like Nina Sutic-Bata, manager of underground utilities for Victoria’s Engineering and Public Works Department.

As is the case in many municipalities, Victoria’s aging sanitary sewer system is responsible for many of the department’s challenges. “Because it’s an old system, we have high rates of I&I,” says Sutic-Bata. “And then on top of that there are new regulatory requirements for reduction in I&I rates, so really, many challenges are simply due to the age of the system and everything else that results from it.”

The city of Victoria serves 90,000 customers and sits on three major earthquake fault lines on the southern tip of Vancouver Island off of Canada’s Pacific coast. Consequently, earthquakes, sea level rise and severe weather related to climate change are all very real challenges for public works officials. Last November, the city saw widespread flooding that put major pressure on its sanitary and storm systems.

“There is a history of big earthquakes happening every 350-500 years, and it looks like we are due for a big one in some 50 to 100 years,” says Sutic-Bata. “But we also have small quakes happening all the time, so that’s a real ongoing risk for us.”

The additional I&I flow is obviously unwanted from an expense standpoint, as Victoria is billed for the water it sends to its treatment plant, but it’s not just about cost, according to Sutic-Bata.

“We want to protect the environment, including marine life, and also avoid public health issues that can result from harmful sewage overflows. Victoria is a tourist destination as well, and we have beaches and parks adjacent to the ocean, and overflowing into the ocean is not very inviting and appealing to tourists.”

Asset renewal program

While the city’s ambitious sewer renewal program has been ongoing for decades in some form, the city has intensified its efforts in the last 10 years. “We established a flow monitoring program, completed a sewer condition assessment, created a hydraulic model, completed a master plan, et cetera, and we started studying inflow and infiltration reduction.”

The city also embarked on projects funded via Infrastructure Canada’s Disaster Mitigation and Adaptation Fund after Sutic-Bata applied for a federal grant in 2018. Victoria received the grant in 2019 and started design and construction work in 2020. “This program consists of 78 projects — water, sanitary sewer, storm drain. Within the sewer network, we have 25 projects that are funded by this grant.”

While there’s some restoration work yet to be completed on the city’s 2021 slate of projects, they’re considered finished, and there are plenty more on deck for 2022. Staying ahead of problems is the name of the game, and Victoria targets the areas of the system that are most likely to fail first or those that could have outsized risks associated with them.

“With this proactive approach we reduce the risk of massive failures that would have a substantial impact on public health and also the budget. And this approach helps us with the best use of the available resources, like time, money and labor, and also allows us to explore new technologies and improve performance. So it provides flexibility in dealing with ongoing and future issues.”

Private-side mitigation

Sutic-Bata estimates that between 40-60% of the city’s I&I comes from infrastructure on the private side. Working with property owners is a complex issue, and the city of Victoria is a pioneer among utilities trying to incentivize them to fix their sewer issues with a city-sponsored rebate program. Public Works has presented the city council with a phased approach that would focus on raising property owner awareness, conducting inspections and talking about rebates and regulations in phase one; adding rebates for pipe renewals in phase two; and revisiting what the city has learned to tweak that process in phase three.

“The main thing is that we would work with property owners to try and help them with rebates and incentives,” says Sutic-Bata. “All those elements of the program are going to be refined as we move. It’s not something that very many municipalities have done, so we have to be careful to do this in the best way for us and for property owners.”

The report and phased approach were received well by the city council, and Sutic-Bata says she’s confident its members are on board with the program.

As far as getting the work done, officials plan to encourage the use of trenchless technologies whenever it’s possible. “It’s usually lower cost than using digging, it provides us with protection of trees, and also has a smaller carbon footprint, so those are all benefits. On the public side, we have been using trenchless technologies, including CIPP, for more than 10 years.”

Planning and outreach

Sutic-Bata had sound advice for other utilities dealing with I&I issues: Develop a strategic plan.

“Some of the steps that we’ve taken, I think, have worked out well for us. First of all, start taking an inventory and complete condition assessment. Hire a consultant to study I&I based on existing data and recommend where to install flow monitors to better pinpoint areas of concern. That’s really important because not all areas of a large system have the same rate. We have some hot spots where the rate of I&I is 10 times the average.”

Once that’s completed, she says the next step is developing a hydraulic model followed by a master plan. “A master plan would actually provide the list of priorities; they would target rehabilitation and renewal based on those priorities.”

Another very important, and often overlooked step, is continuing to educate customers on the importance of sewer systems and their impact on public health and the environment, she says. “And at some point you find messaging to include more details about I&I and the importance of both public- and private-side programs. I find there is a general lack of awareness about underground infrastructure, including sewers, and many of the functions of the systems are taken for granted. So I think raising awareness with the general public and continuous education is really important.”