Canadian Township Addresses Manhole Issues

It’s a situation that towns across Canada and the United States are facing with increasing frequency: Yesterday’s infrastructure no longer supports today’s population.

Although system overcapacity was a known problem for the Township of North Glengarry, Ontario, Canada, the severity of the issue was starkly illustrated last summer when the town got hit with a “one-in-50-years” rain event.

// ** Advertisement ** //

In just one hour’s time, North Glengarry and its surrounding areas received a whopping 6 to 8 in. (150 to 200 mm) of rain, completely overwhelming the sanitary system and causing sewer backups in nine residents’ homes.

Located roughly halfway between Canada’s capital city of Ottawa, and Montreal, Quebec, the Township of North Glengarry is made up of more than 10,600 residents in rural areas and spread across numerous historic and culture-rich communities of varying sizes. Although the flooding was only partially caused by manhole-related inflow/infiltration (I/I) — as Mayor Chris McDonell noted at a Sept. 12, 2012, council meeting no storm water system in rural eastern Ontario is built to handle that kind of deluge — the surcharge crisis was indicative of problems related to the town’s 50- to 60-year-old infrastructure. 

// ** Advertisement ** //

In researching solutions for its I/I-related overcapacity problems, North Glengarry Water Works manager Dean McDonald discovered the Lifespan System at an event hosted by the Centre for Advancement of Trenchless Technologies (CATT) at the University of Waterloo. Hamilton Kent director of sustainable market development Henry Flattery was a presenter at the event, sharing the benefits of the Lifespan System for addressing I/I.

“I immediately thought, ‘This is great!’” remembers McDonald. “The manholes we were using at the time were okay but once you opened them, they weren’t watertight anymore because the design wasn’t practical.”
Lifespan is a patented rubber manhole frame and cover system, manufactured and distributed by Toronto, Ontario, Canada, and Winchester, Tenn.-based Hamilton Kent. The frame is made of 100 percent rubber, designed to better absorb impact and vehicular vibration and reduce the concussive load on the surrounding asphalt. It is also completely watertight, due to its tight-fitting cast-iron or composite lid, which locks to the frame via a patented SHURE-LOK mechanism. Lifespan is also completely non-corrosive, is unaffected by salt and sewer gas and prevents rainwater inflow up to 5 psi and sewer surcharge up to 3 psi.

// ** Advertisement ** //

When McDonald described North Glengarry’s situation to Flattery following the presentation, Flattery said he knew Lifespan was the right solution: not only was its lightweight rubber frame and locking lid ideal for the locations McDonald had in mind, most importantly, it would definitely help reduce I/I and, as such, the load on the township’s already-stressed wastewater treatment plant.

“As a highly sustainable solution, Lifespan saves you from having to convey and treat unnecessary water in your wastewater stream,” says Flattery. “It is exactly the right solution for this type of municipal remediation.”

// ** Advertisement ** //

McDonald agreed and ordered eight units for immediate installation. The results, he says, have been impressive.

“Lifespan is one of a kind. I’d never heard of frames built out of rubber,” he explains. “But they are working great — they held up really well this winter. We’ve had zero issues.”

// ** Advertisement ** //

Four of the Lifespan units were designated and installed in on-road locations and four were designated for off-road use near a very active creek. The second four are particularly critical units for controlling I/I, McDonald says, because the township neither wants the creek’s frequent overflows to contribute to the city’s overcapacity problems, nor for the overcapacity problems to cause contamination of the creek.
“The ease of installing them was a huge benefit,” McDonald adds. “It’s so much easier because they are so lightweight. And when we have to open them up, it’s much easier to close them up. They are really user-friendly and the operators are happy with them too. We have already ordered more and will be installing them this summer.”

The manholes are part of a township-wide project North Glengarry is embarking on to upgrade its aging infrastructure and improve its drinking water quality and supply. The Strategic Plan, to be implemented over the next three to five years, includes a Sewage Master Plan with a focus on addressing lagoon capacity.
As such, the North Glengarry Public Works Department has its plate full in 2013 and anything that makes the work easier is much appreciated by the crew, McDonald says.

// ** Advertisement ** //

“We’re conducting manhole inspections across town, so every manhole cover will be opened,” he explains. “The operators are cursing the old-style watertight covers that we were using before the Lifespan Systems. They are almost impossible to reinstall properly, whether you’re trying to line up the bolt holes or trying to keep the gaskets in place.”

Although North Glengarry’s situation is one that is faced by many townships, cities and municipalities across North America, the township is taking a particularly rigorous approach to remediation.

// ** Advertisement ** //

As any public works manager, council member or mayor can empathize, the township faced significant resident distress after the 2012 storm, which is starkly illustrated in the minutes from a fall council meeting following the deluge. In the meeting minutes, the township offers the purchase of a new closed-circuit television (CCTV) camera system as an example of what it is doing to help reduce the chances of similar failures happening again in the future.

“Rather than renting similar units and using them sparingly, the investment in the camera was made to increase flexibility and lower costs so that it can be used more often to locate problem areas,” according to the meeting’s minutes. “That camera will be used for video surveillance of the affected area sewer mains to see if any defects are present.”

// ** Advertisement ** //

The Township of North Glengarry also faces significant issues with its drinking water and is at the forefront of the Glengarry Regional Water Supply Project (GRWSP), a long-term initiative to upgrade the region’s water quality and supply.

The $50 million project will see treated drinking water from the St. Lawrence River via the City of Cornwall’s water system and transport it north through South Glengarry to the villages of Maxville and Alexandria. The system may also service other local communities. The project is two-thirds of the way through the design and assessment process.

// ** Advertisement ** //

Although manhole access is just a small part of North Glengarry’s long-term infrastructure vision, it does affect many other aspects of the underground infrastructure system. Watertight manhole frame and cover systems mean the elimination of inflow at the top of the new manholes, making a small but important difference in the amount of water being unnecessarily treated at the township’s treatment plant.

“It takes 1,000 kWh to treat a million liters of wastewater,” Flattery emphasizes. “If up to 50 percent of what you are treating is rainwater, the impact on our resources and environment is staggering.”

// ** Advertisement ** //

As communities across North America embark on similar journeys to improve underground infrastructure, sewers and manhole access will continue to play pivotal roles in the process. Even though they are not the center of public attention — until basement floods make headlines —they are, in fact, the centerpiece of clean, safe and energy-efficient communities.    

Katie Bailey is a writer with motum b2b, a Toronto, Ontario-based marketing agency specializing in business-to-business communications.

// ** Advertisement ** //
// ** Advertisement ** //