The City has some 250,000 active laterals, many over 100 years old and are experiencing the effects of their age and the normal wear and tear. In 2006, City Council passed a resolution in which the city would assume responsibility for the operation and maintenance of all service laterals from the mainline sewer to the property line.
In developing a program to address the condition of the laterals, council insisted that the means to rehab program not disturb the environment and property owners — i.e. not digging up driveways, lawns or trees. The City of Hamilton has been an aggressive proponent of trenchless technology in the past and in recent years has encouraged the industry to develop a completely trenchless rehab solution to address its laterals.
“We have been fairly aggressive with our laterals, just as we have with any other rehab program. It just took a little longer for the lateral technology to catch up to the mainline relining technologies,” said Erika Waite, the city’s senior project manager of infrastructure programming. “Lateral liners have been around for a while, but they haven’t always been exactly what [the City of Hamilton] needed as a municipality.
“There were a few lateral products available but LiquiForce was able to develop one that didn’t require the cleanout,” Waite said. “We told them if they needed a testing ground for it, we are here.”
LiquiForce, a Kingsville, Ontario-based no-dig contractor that specializes in pipe and lateral lining, has worked with the City of Hamilton in recent years on various rehab projects. Over the last several years, the company has been working on a completely trenchless lateral repair system that would meet its needs as a company, as well as the City of Hamilton’s. The product LiquiForce came up with is its Junction Liner.
LiquiForce has been rehabbing laterals since the late 1990s, employing the traditional methods in the process. LiquiForce is a contracting company that manufactures its own equipment, including the cameras, cutters and liners. Early on, company CEO Kim K. Lewis said he knew he and his team wanted to streamline the lengthy lateral lining process and make it more cost-effective for the company and their clients.
“We looked at the components that make up lateral lining, which unlike full-length lining, is much more complicated,” he said. “There are so many more details to be managed. There are 13 individual steps from the first video to the final post- video for a lateral liner. There’s so much data to be managed to gain productivity and gain control of large projects.
“We got aggressive about two years ago about putting a system together where we could lift the manhole cover off, send devices down the mainline sewer and turn and go up to the home … creating a piece of equipment that would send a camera up the line so it serves as a big attachment with many different heads on it, such as a camera head, a cutter head and an electronic measuring device.”
What Lewis and his team came up with is the Junction Liner — a two-part robotic system that 1) cleans, inspects and measures the lateral liner and 2) goes through the manhole and sends a new liner from the main up to 150 ft to the lateral. Total curing time is about an hour.
Simply put, LiquiForce’s new state-of-the-art lateral repair process for sewer pipelines cleans the existing lateral connection, measures it for a new, custom-made replacement liner and installs the new lining system all from within the existing access points (manholes) of the mainline sewer connection. Access to homes or businesses in not necessary while repair work is under way and there is no need to dig a traditional clean-out on the property.
Lewis said the cleanout is not needed and just becomes an added cost for each lateral being rehabbed. “In the past, the cleanouts were used for cleaning the lateral when we didn’t have devices that could go down the main and clean. They also used to send a camera down the cleanout to make sure the liner being launched was accurately lined up. We now have systems that get around all of those previous needs for a cleanout.”
The system’s PFM truck (Prep from the Main) is described as a big, long, large vehicle that has a studio inside with four large monitors where a crewmember can watch all operations going on underground. The truck is also equipped with a series of reels and high-pressure equipment, measuring devices and cameras that are all built into one train that travels down the mainline to each lateral location. The truck also has a comprehensive, Web-based data management center that manages, tracks and stores the data for each job for LiquiForce and the customer.
Lewis noted that LiquiForce received support for development of this product from the federal government in Canada as well as the local, provincial government. “The government financial supports the infrastructure programs and they looked at it and realized that they will spend millions of dollars on lateral programs. Our system can reduce the cost of these projects by 20 to 50 percent, in some cases,” Lewis said.
In 2011, the Junction Liner was put to the test in a trial project in the City of Hamilton. Lewis reported that the system was used on 391 lateral installations, with only three of them requiring a cleanout due to location. LiquiForce recently signed a three-year contract worth $12 million with the City of Hamilton to rehab approximately 2,000 laterals in that timeframe using the Junction Liner.
“This is a significant program in Hamilton. With this contract, they will all be done using this totally trenchless process,” Lewis said. He estimates that more than 500 laterals will be rehabbed each year of the program.
The City is more than pleased with the result of the Junction Liner. “It’s been great and we’ve had no issues with it,” Waite said.
She noted that because the system eliminated the need for cleanout installations, it further eliminated the cost of legal surveys, restoration of lawns, driveways and trees, as well disturbing the property owners.
As Junction Liner has been introduced into the market, LiquiForce is working on an upgraded model of the system. “Version No. 2 of the system will simplify the process even more and will bring total costs down even further,” Lewis said.
Sharon M. Bueno is managing editor of Trenchless Technology.