Canadian Underground Infrastructure Logo

A tale of two manhole fixes

Failing manholes in Edmonton and tiny Yukon community treated with Permacast and Centripipe spray liners by AP/M Permaform

AP/M Permaform rehabilitate failing manholes and sewers using the Permacast and CentriPipe systems.
AP/M Permaform rehabilitate failing manholes and sewers using the Permacast and CentriPipe systems.

Company info

PO Box 555
Johnston, IA
US, 50131


Phone number:

Read more

Canadian contractors are cost effectively rehabilitating failing manholes and sewers without excavation or barrel replacement using the Permacast and CentriPipe systems developed by AP/M Permaform (AP/M) and distributed by Martech, Inc. Edmonton-based OSCO Mudjacking & Shotcreting Ltd. applied Permacast on two manhole projects with widely varying challenges:

  • A new 9-metre manhole installed as part of Edmonton’s massive project converting the QE II Highway and 41 Avenue SW connection to a grade-separated interchange.
  • Six failing manholes in remote Carmacks, a Yukon village.

Innovation in a tricky situation

To withstand increased loads from a new overpass being constructed as part of the interchange project, a 145-metre section of existing 54-inch concrete sewer line had to be structurally rehabilitated. To facilitate this work, a new 9-metre (29.5- foot) manhole was installed to provide access at the section’s midpoint.

The sewer was in reasonably good shape, but displayed microbiologically induced corrosion (MIC) in the top half, where concrete was exposed to hydrogen sulphide produced by thiobacillus bacteria. OSCO used CentriPipe to create a new concrete pipe within the existing damaged pipe. After dewatering, the CentriPipe spincaster was inserted into the pipe through the newly installed manhole, pushed to end points within the pipe, and withdrawn while pumping an engineered fine aggregate concrete to the spincaster. The material used was AP/M Permaform’s PL-8,000, mixed with ConmicShield, a concrete additive that inhibits microbial activity. Concrete treated with ConmicShield has been used for decades, and permanently prevents MIC.

PL-8,000 is a fibre-reinforced cementitious mortar that adheres tightly to existing substrates – in this case, the original concrete sewer – so that no annular space is created for exterior water flow. In effect, a new smooth, structurally sound and waterproof concrete pipe is created within the old pipe. The fibre-reinforcement and other factors allow the use of thin layers, so sewer flow volume is only minimally affected. The compact spincaster enables cost-effective use of this solution in situations where other technologies, such as CIPP, are unworkable.

The installed manhole was a new concrete ring structure that didn’t need rehabilitation. On the other hand, it is a large sewer installation that will remain important for access to a sensitive area, so the lead contractor asked OSCO to structurally reline this deep manhole to preserve it indefinitely.

For manhole rehabilitation, OSCO employs the Permacast bi-directional spincaster, lowering it into the manhole and withdrawing it vertically. AP/M’s MS- 10,000 is used for manhole lining, also mixed with ConmicShield. “Using ConmicShield is a very good idea in any sanitary sewer, where organic material and turbulence lead to microbial damage,” says OSCO owner Don Moroz. “It’s a ‘best practice’, and we recommend it to greatly extend the lifespan of concrete sewer structures.”

Surprisingly, the depth of the manhole was not really an issue. “Nine metres is unusually deep in this network,” Moroz concedes. “But it’s well within the capacities of the Permacast system. We set up over the manhole, lowered in the spincaster, and withdrew it while spraying on MS-10,000. Sewer flow was not affected at all.” Two passes were required to build up an inch of thickness. As with the sewer rehabilitation, the process casts a new, joint-free pipe within the original manhole, and manhole diameter is not significantly reduced.

In addition to low cost and minimal disruption, another advantage of the spincasting solutions is speed; all told, OSCO spent just three days on site rebuilding 145 metres of sewer pipe and 9 metres of manhole chimney.

Remote location, difficult conditions

Carmacks, Yukon, is in some ways the opposite of Edmonton; it’s remote, has a population of just 503 and its infrastructure is relatively undeveloped. “Basically, the sewer system is the only infrastructure – even water is trucked in,” says Darrell Peters, project facilitator at Yukon Engineering Services, Inc.

As part of a review funded by the Yukon government, Peters identified six manhole barrels that were leaking badly and overwhelming the community’s small wastewater treatment plant. “The system is near a big river, and main sewer lines are actually in the water table,” Peters explains. “The manhole barrels were just part of the project, but they were a main source of infiltration. I could see water pouring in like a garden hose, and I had to dewater just to get a good look at the situation.”

At the time, Peters installed plugs to temporarily fix poorly installed seals and cracked barrels. For a permanent solution, he decided to try Permacast, as offered by OSCO. “I thought it could work here at a relatively low cost, and would be a good choice given the remoteness of the location; the nearest source of supplies is White Horse, about 200 kilometres away.”

For OSCO, the main challenge was weather; at time of rehabilitation, nighttime temperatures were -15 degrees C, with daytime temperatures climbing all the way up to 5 degrees C. Herman Nelson heaters were brought on site and connected to 12-inch hoses that brought manhole barrels up to workable temperatures. OSCO also had to contend with insulated frost lids, a unique feature of Yukon manholes used to prevent sewer freezing in winter.

Aside from those challenges, rehabilitation was routine. MS-10,000 mixed with ConmicShield was again used, and all six barrels, about 3 metres deep, were repaired in just two days.

Peters considers the project a success, and says he is likely to use Permacast again. Given the extreme range of challenges successfully met by these two early projects, it’s likely that the complimentary systems will be used routinely throughout Canada.

More from Projects

Sanexen successfully finishes NYC tunnel repairs in record time

During the weekend of October 20th, Sanexen Water, Inc., a member of the LOGISTEC family, successfully completed major repairs in the Lincoln Tunnel in New York City with minimal impact. When the Port Authority of New York and New Jersey (PANYNJ) began planning repairs and upgrades to Route 495 and the Lincoln Tunnel, one of the requirements was to repair two cast iron cement-encased water main sections at each end of the tunnel that supply water for fire prevention.  Sanexen Water was selected for its unparalleled expertise and its innovative Aqua-Pipe trenchless technology, to repair these aging water mains while other construction work was in progress. New trenchless technology is used for the replacement or rehabilitation of existing underground infrastructure with minimal excavation and disruption to surface traffic. 

Final double breakthrough at the Emscher sewer

With the breakthrough of the last two tunnel boring machines into the target pit in Oberhausen-Biefang on June 12, 2017 the tunnel and pipe jacking work for the Emscher sewer has been completed. Over a period of 25 years numerous Herrenknecht tunnelling machines and a wide range of additional equipment were successfully used in the Europe-wide unique environmental and sewage project of Emschergenossenschaft.

Bulls Bridge Replacement Penstock

In the early 1900s, the New Milford Power Company successfully completed the first commercially viable hydroelectric power plant on the Housatonic River in Connecticut.  The project, Bulls Bridge Development, broke ground in spring 1902 and was in operation by 1903. Bulls Bridge was named after the Bull family that had lived in the area for generations. 

Herrenknecht tunnel borers continue success story in L.A.

Los Angeles is a vibrant center of international film art and innovation - not just on the surface. The area below ground is the scene of state-of-the-art engineering achievements. German high-tech machines from Herrenknecht are creating underground arteries for the American city. Tunnel boring machine (TBM) , Harriet successfully completed her drive for the Crenshaw/LAX Transit Project in April 2017. Angeli just finished digging the first of two tunnels for the Regional Connector Transit Corridor on July 18th. From spring 2018 onward the tunnel boring stars will have additional company: for each of the "Purple Line Extension Sections 1 + 2", two more Herrenknecht TBMs will be working their way through the difficult ground. All three projects are part of the strategic subway extension in L.A. to relieve the traffic above ground.

Mexico City’s Record-Breaking Crossover TBM makes Final Breakthrough

In June , a select group of project officials, including Mexico's President Enrique Peña Nieto, celebrated the final breakthrough of an epic tunneling project.  The 8.7 m (28.5 ft) diameter Robbins Crossover TBM is the first such hybrid machine to operate in North America, and it completed the Túnel Emisor Poniente (TEP) II on a high note.  The TBM, known an XRE—a Crossover (X) between Rock (R) and EPB (E) TBMs—navigated fault zones, variable ground, low cover, and more to achieve a national record of 57 m (187 ft) in one day as well as maximum rates of 231 m (758 ft) in one week and 702 m (2,303 ft) in one month. 

Speedy pipeline connection in Australia

In just three months Australian drilling contractor Dunstans Construction Group installed a 700-meter-long pipeline in Anglesea (Victoria). A 250 tonne HDD Rig from Herrenknecht played a key role in the achievement. Within a very short time the construction crew built a sea outfall with the machine, as well as pulling in the pipeline all the way back to the local water treatment plant.

Worksite injuries driving demand for composite manhole covers

Composite materials are in demand as industries are experiencing hazards and injuries when using traditional steel and other metal products. Reports of crushed and amputated fingers and toes along with burns, back injuries and other ailments have given industries ranging from data centres to water treatment plants a reason to seek safer alternatives. In the United States in 2014-15 there were 3,675 incidences of reported injuries within the manufacturing industry alone. Thirty-two percent of these incidences were reported as back injuries which led to a total of 125,880 missed working days. Composites are an ideal solution to these problems due to their lightweight yet durable properties. By using lighter materials, operational injuries are prevented, worksites are made safer, and ease of installation and maintenance is made available to utility workers and contractors.

Montreal-based consultancy completes inspection and leak detection of six 1,200-mm steel watermains and one 1,500-mm PCCP main in Montreal

Since September 2013, GAME Consultants has been paving the way for the next generation of watermain condition assessment tools by using existing tools and working to improve the results with every project. The company’s position is to equip itself with a wide range of tools designed exclusively for use in watermains.

Subscribe to our free newsletter

Get our newsletter

Learn more

Robbins achieves another breakthrough in Bangalore

On June 8, 2016, one of two 6.4 m (21.0 ft) diameter mixed-face EPB machines broke through at Namma Metro. After being launched in March 2015, the TBM named Kaveri made its way through its difficult 750 meter (2,460 ft.) drive from Chickpet to Majestic. Sister machine Krishna, launched in December 2015 is not far behind, and is expected to break through in approximately two months.

Completion of trackwork for the Toronto-York Spadina Subway extension

A special event was held to celebrate the completion of trackwork in the new Toronto-York Spadina Subway Extension (TYSSE) tunnels and stations where a total of 17.4 kilometres of track and four sections of special track have been installed. Dignitaries walked down into the station to track level where they participated in a ceremonial tapping in of the last clips that hold the rails in place.

Pipe change at Prince Edward Island watermain expansion project

As a PVC-friendly city, Summerside, Prince Edward Island planned to use PVC pipe as it began Phase II of its Pope Road watermain expansion project. The project required 300 metres of 400-mm (16-inch) pipe, and was taking place in an area of the city with no existing water line.

Waterloo biofilm battle

In Canada, the quality of drinking water that flows from the taps of most households is for the most part taken for granted. While the country has pockets of populations with water quality concerns, Canadians generally regard their drinking water not only as safe, but of a higher quality than other developed nations.

Innovative approach to sanitary sewer cleaning

Civil engineers could be looking at London as a template for hard-to-access sewer cleaning jobs. The Ontario municipality recently installed three specialized manholes with sealed access flanges into one of its longest and oldest sewers in order to clean the pipe, after a camera probe two years ago identified it as being partially filled with solids and grit that would eventually restrict flows.

Turbidity problem addressed

In Dieppe, New Brunswick, complaints about the quality of drinking water running through a decades-old water main had city engineers scratching their heads for a solution that wouldn’t create too much disruption for residents.

Robbins EPB Begins Light Rail Link

Tucked away on a small jobsite in a quiet neighbourhood bordering a busy interstate highway, a Robbins Earth Pressure Balance (EPB) machine underwent Onsite First Time Assembly (OFTA). The OFTA method allows for TBMs to be assembled onsite, and results in time and cost savings to the contractor. On November 17, 2014 unbeknownst to commuters driving by, the 6.65-metre (21.8 feet) TBM rumbled to life and began its journey south into the city of Seattle, Washington.

Concrete Conduit Challenges Pipe-Bursting Contractor

One of the most effective ways of replacing a pipe using trenchless technology is pipe bursting, which replaces a traditional construction trench with launching and receiving pits that pull the new pipe through the existing one, breaking the old pipe into fragments that stay in the ground in-situ.

Subscribe to our free magazine

Get Our Magazine

Paper or Digital delivered monthly to you

Subscribe or Renew Learn more

Tendering the Environment

Environmental concerns and mishaps have been the cause of many delays, cost overruns, shutdowns and legal implications over the years. Many people in the industry will read this and think that delays caused by environmental factors are a result of multiple, complicated or changing regulations. While these are sometimes contributing factors, the root of the problem starts with contract tenders, more specifically the way they are written or not written.

Breaking Through to Billy Bishop

It is only 120 metres across the Western Gap of Toronto Harbour from the Toronto waterfront to the Billy Bishop Toronto City Airport (BBTCA) but it still requires a ferry boat ride for passengers going to and returning from the airport on Toronto Island. The ever-increasing popularity of this airport with close proximity to downtown Toronto has pushed the ferry capacity to its limits.

CUC crews endure extreme conditions to complete Air Liquide project

Working in underground construction, it’s common for utility contractors to encounter unexpected challenges. In fact, it’s those challenges that often test a company’s mettle, its expertise and its people. A successful outcome not only brings a sense of pride to those who were involved in the project, but can often cement a relationship with a customer that is both long-lasting and fruitful.

Revitalizing Toronto’s waterfront roads

Downtown Toronto benefits greatly from the natural beauty of Lake Ontario providing it with a stunning waterfront that attracts tourists and local residents on a daily basis. Combining traffic, transit, tourists and other factors in an area that was designed and developed many years ago has caused a call for revitalization along parts of the city’s waterfront.