In Lordsburg, New Mexico, the utility division of Morrow Enterprises Inc. is in the middle of a sewer line relocation project to help accommodate Union Pacific’s plans for future railroad expansion. The job entails installing four new sewer pipes under existing railroad tracks and a highway.
While this project isn’t a typical major sewer rehabilitation, something Morrow Enterprises handles frequently, its location and the need for accuracy makes it a challenging assignment. To get the job done, the Morrow Enterprises crew is relying on one of the oldest and most reliable trenchless methods — auger boring.
Morrow Enterprises is best known around Southern New Mexico for doing municipality utility work, paving and grading. However, the company is also skilled at performing the niche service of auger boring.
The Las Cruces, New Mexico, company was founded in 1973 by Leon Morrow. After a few years, his two sons, including current president, Leonard Morrow, joined in the business. The family-owned company dug septic tanks in those early years but have since evolved into more general contracting. Morrow Enterprises now employs around 80 people and was named a 2018 Star Client by the New Mexico Small Business Development Center.
According to Morrow Enterprises president Leonard Morrow, his company has focused on the needs of Southern New Mexico and has expanded its services accordingly. “Around four decades ago, we extended our services to include auger boring because subcontracting the work was becoming too much of a challenge,” he explained. “Having someone else handle the bores was throwing off the timing of projects so we decided that it would be better for our customers if we just did it ourselves.”
The Lordsburg Job
Leading the efforts on the Lordsburg job, as well as hundreds of other auger boring projects over the years, is Morrow Enterprises utilities superintendent Justin Sparks. “Justin was with me the day we bought our first auger boring machine at auction many, many years ago. He and his team do a great job,” Morrow commented.
Over the course of several weeks, Sparks and his team are performing four challenging underground crossings, including a 24-in. diameter, 440-ft bore, a 24-in. diameter, 130-ft bore, a 42-in. diameter, 220-ft bore and a 24-in. diameter 350-ft bore.
“Making sure everything is set up correctly is the most important part of an auger boring job,” Sparks explained. “Everything needed to be on-grade for this, and there was a very low tolerance for any deviation, which meant our pit floor had to be dug to the right depth, and we needed to stay on target with the bore path.”
Setting up an auger bore starts with potholing existing utilities, digging entrance and exit pits, pouring a concrete slab for the auger boring machine, setting up the tracks and then dropping in the machine. The utility crew is using two different size units on this job, a new McLaughlin MCL 54/60 auger boring machine for the 42-in. diameter bores and its older, but reliable, McLaughlin MCL 24 auger boring machine.
For this job, Morrow Enterprises is trying something they have never used before — the McLaughlin On-Target steering system. According to Morrow, one of the aspects he’s never liked about auger boring is not knowing precisely where the casing was in the ground. “Even with other steering systems we’ve used, or we made ourselves, there was always a chance of being off, sometimes it could be by as much as 7 ft,” he explained. “For us, that’s not close enough. So, when we heard about the McLaughlin On-Target system, we decided to give it a try.”
The McLaughlin On-Target steering system’s first test on the Lordsburg job was the 440-ft bore under railroad tracks using a 24-in. head and an MCL 54/60 auger boring machine. The crew executed the job perfectly. At 300 ft, the length of the tunnel, there was absolutely no grade deviation, and the line was perfect. The team continued to push to a distance of another 140 ft to eliminate the open cut and was off grade by only 0.25-in. and within an inch of the line.
“We are thrilled with the On-Target steering system,” said Sparks. “It was easy to check where we were at and make adjustments. Every time we pulled the auger back, we could check the position of the twin line projection lights. It’s pretty exact. With other systems, we just didn’t know, we were guessing.”
After that bore was completed, the crew flipped the auger boring equipment around in the same pit to complete another 140-ft (conversion) bore under the highway and then connected the casings in the pit.
Representatives from McLaughlin Underground were on site for the first job, which Sparks says he greatly appreciated. “With this being the first time, we used the On-Target system, having them there was helpful,” he explained. “They made sure we had everything connected correctly and provided direction when we needed it.”
The Morrow Enterprises’ crew is in the middle of the next bore. They are using a larger 42-in. On-Target steering head to go 220 ft. Once the casings are installed, the crew will run a 24-in. diameter sewer pipe through it.
“The pit on the bore is between 9 and 10 ft,” Sparks explained. “It took about half a day to dig it out, pour our pad and let the concrete set for a couple of days. After that, we set the tracks and got to work. So far, everything has been going smoothly. We’re expecting the results to be similar to what we did on the last bore.”
The final 350-ft bore, also needs to be on-grade and will house a 10-in. sewer line.
Renting and Buying
With the success Morrow Enterprise had using the McLaughlin On-Target steering system, Morrow and Sparks decided to purchase the 24-in. On-Target steering system. “That’s a pretty common size casing on auger boring projects, so we know it will be used often,” Morrow explained. “Last year, we had a project where we did 42 bores that were 24-in. in diameter.”
Since there isn’t as much of a demand for 42-in. bores, Morrow Enterprises chose to rent that head. “Having the option to buy or rent directly from McLaughlin is beneficial,” Morrow added. “They get it to us when we need, and if we need on-site support, they will send someone out. It’s a great partnership.”
Morrow discussed one other important component of this project — the work of his team is what has made this job, along with all of the company’s other utility projects, successful. “Justin (Sparks) and his team has done wonderful work,” he said. “They are the reason why Morrow Enterprises continues to grow and impress our customers.”