December 2020 Vol. 75 No. 12
Directional Drilling
Delivering Clean Water to Canadian First Nation Communities
For residents in the Wauzhushk Onigum and Obashkaandagaang First Nations, clean, safe drinking water from the faucet is a luxury that hadn’t existed in nearly a decade. Located near Kenora, a small city situated on the Lake of the Woods in northwestern Ontario, Canada, about 124 miles east of Winnipeg, both of these communities had been under water-boil advisories since 2012.
With funding provided by Indigenous Services Canada (ISC) and the federal government, a project to connect the First Nations’ water and sewer infrastructure to the city of Kenora’s municipal water system was designed to greatly improve the communities’ poor water situation.
The full scope of the project included a new water plant with treatment and disinfection equipment, a below-grade concrete water reservoir under the building, a genset for backup power, a parking area around the building, electricity and communication lines to the building, a septic field for wastewater, a 246-foot water intake pipe and 311-foot backwash outfall pipe into Lake of the Woods, multiple distribution pumps, and 3,822 feet of watermain piping. Completed, the new facility was designed to eliminate two long-term water advisories and restore fresh drinking water to the two communities.
To install the water pipes from Kenora to Lake of the Woods, the city’s sewer and water department contracted Staal Irrigation & Contracting of Rosslyn, Ontario, for the horizontal directional drilling (HDD) work. Using a Vermeer D40x55DR S3 Navigator rig to complete the boring, owner Ian Staal and his crew were able to complete their part of the project in less than seven weeks.
“It was quite the project – not your run-of-the-mill drill shot into a lake, that’s for sure,” said Staal.
Drilling to the lake
The project called for the Staal crew to install two lines – 18-inch and 16-inch diameter – of Schedule 11, HDPE pipe on the Kenora side of the lake. For both pipes, the crew bored a 24-inch diameter hole. From where the drill was positioned on shore, each bore was approximately 370 feet in length.
Staal said the combination of a Mincon air hammer and Century Products’ Insta-Vis foam drilling fluid was ideal for tackling the rocky soil conditions for the 5.25-inch pilot bore. Powering the Mincon tool was a 1,600-cfm air compressor running at 375 psi. With this equipment and pressure, Staal said it was all about getting the bore hole right the first time.
“You can’t push it; you can’t rush it. You just have to be very methodical and think of every single move because you cannot redo your bore,” he said. “Because we were in rock, we really had to pre-plan every single inch, every foot and every percent.”
On the way back through the hole, the crew used a Vermeer reamer to expand it to 12 inches in diameter. Using the same reamer, but with a different carbide tip on the front end, the crews continued to go back through the bore path, lapping and spinning to increase the holes from 12 inches to 24 inches. Throughout the bores, the crews used a Digital Control DigiTrak Falcon F5 locating system to track their progress.
“Every time we needed to make a tool change, we had to do it on the lake. On the first bore, we rented a barge with a big crane and used that to help us push out additional rods, giving us more flexibility. Then we would go down, chain on the end of the pipe and crane it out. As the person on the drill would push up more rod from shore, the crane would give us more leverage and allow the pipe to come up easier,” said Staal.
“Then, we would get the pipe up on the edge of the barge – still connected to the drill – ratchet it all down on the deck of the barge, then lower the drill-head reamer down into the lake and pull it back,” Staal added. “It was a bit of a process, so on the second one, instead of using the barge, we used divers.”
Facing challenging conditions
One challenge encountered during the bores was the ground conditions changing unexpectedly on the lakebed.
“It was supposed to be all bedrock,” said Staal. “The problem was that about 200 feet out on the beach shore, there was a section that went from rock to native soil – and then went back into rock. Using that much pressure there and trying to hammer through, and then abruptly finding out that it’s not all rock, was really surprising. We were probably at a depth of 20 feet when we hit the dirt pocket.”
To alleviate the situation, his crews used fluted reamers with clay cutters on the end of their drilling rig to clean out the drill hole.
Staal estimated they bored out around 60 feet from shore and emerged in about 10 feet of water. Since the crews were going through differing ground conditions, their drilling averages varied widely.
“Sometimes we were able to go 10 feet, which is one rod, in about 35 to 40 minutes,” he said. “Other times, it would take 90 minutes or more to do the same amount of work.”
Staal noted that it can be stressful, but being patient is the best way to work through these types of challenges.
“You have to just be persistent and take your time,” he added. “I mean, we just let the air and the bit do the work, which meant that sometimes we were sitting there on the drill and going slowly. That is the best way to get the job done right.”
Connecting to the other side
According to Staal, at the same time his crew was doing the HDD work on the Kenora side, another contractor was doing all the sewer and water lines on the reserve side. That contractor used breakers and vertical drilling to blast the bedrock, then dug the material out of the way and trenched the pipe in.
Once the HDD bores to the lake were completed on the Kenora side, and the trenching was done on the reserve side, the project specs called for the two new pipes to be installed on the lakebed a little over 9 feet apart.
“The timing worked out really well,” said Staal. “While we worked on our bores, the other contractor was finishing the work on the reserve side. We finished up on both sides of the lake at about the same time and were ready to pressure test, set it up and tie it all in together.”
The pipe was welded together on the reserve side, and then the pipe – filled with air so it would float – was pulled into place with several boats. Divers connected the pipe to the end of the drill string above the “daylight hole” (bore exit point on the lakebed), and Staal’s crew and the Vermeer drill took it from there.
“When we brought the pipe to shore, we pumped water from our vac truck into the line to act as a counterweight and get the line to lay down in the water, so we would have a better entry angle,” explained Staal.
Once the pipe was pulled into position and connected on both shorelines, the two lines were anchored to the bottom of the lake using concrete weights.
For the Staal team, this Lake of the Woods water and sewer project was just another example of how far the company has come – from only installing sprinkler systems – in the past decade. Since then, Staal Irrigation & Contracting has expanded to five HDD crews with five Vermeer HDDs and several vacuum excavators.
The Lake of the Woods project was one of the first times the crews have operated a Mincon air hammer, but Staal said the team at Vermeer Canada and Mincon supported them every step of the way.
“We really appreciate all the time those folks spent with our guys on this job. They were every bit as invested in seeing us be successful on this project as we were, and that means a lot to all of us,” he concluded. •
FOR MORE INFORMATION:
Staal Irrigation & Contracting, (807) 577-1441, staalltd.com
Vermeer Corp., (888) 837-6337, vermeer.com
Century Products, (262) 832-3600, centuryproducts.net
Mincon, (618) 435-3404, Mincon.com
Digital Control Inc., (800) 288-3610, digital-control.com
Comments