A Nebraska-based Company Completes Water Main Upgrade Using Vermeer Drill for HDD in Pella, Iowa.
Randy Happel Apr 04, 2012
Over the 19-plus years he has been involved with horizontal directional drilling (HDD), Craig True has gotten to know the Vermeer Corporation, along with many of the folks who reside in Pella, Iowa, pretty well. Having several times visited the 1.5 million square ft Vermeer manufacturing facility, located on the east side of this vibrant central Iowa town, he has often experienced their hospitality and exchanged pleasantries with the locals. Consequently, True wasn’t at all surprised by the keen interest he and his Nebraska-based Horizontal Boring & Tunneling Co. crew experienced from those residing along the 1,600 ft (487.6 m) installation route when they arrived to complete a water line upgrade project in Pella last November.
“There are likely only two communities in the entire world where so many of the residents not only understand HDD, but can probably suggest a drill model that would work best for a specific job,” True said. “One of those towns is Pella, Iowa.”
True, along with his years of HDD experience, recently joined Horizontal Boring & Tunneling Co., based in Exeter, Neb., as directional drill superintendent. Horizontal Boring & Tunneling Co. is one of the nation’s leading trenchless installation contractors with Midwest roots.
In 1982, Brent Moore and Roger Hall purchased the Horizontal Boring Company and added “Tunneling” to the official name and the Horizontal Boring & Tunneling Co. was established. Today, the company continues to grow and flourish and its success has led to further expansion and transition. Now owned by Brent Moore, Horizontal Boring & Tunneling Co. is currently supported by a workforce numbering more than 80 strong - all of whom are trenchless experts in their own right.
According to True, the company ventured into directional drilling in 1995 and trenchless installations have grown exponentially ever since. Given the company’s small town and rural community-based roots, it’s not surprising that over 75 percent of jobs completed by Horizontal Boring & Tunneling Co. take place in mostly suburban locations outside of the Cornhusker state. Hence, people in communities from several different states have witnessed the Horizontal Boring & Tunneling Co. fleet of equipment in their neighborhoods to complete a gas, sewer, water or fiber installation project.
Demand Exceeds Capacity
It is a situation that has become all too common among an increasing number of towns and cities across the U.S. aging utilities, whose capacity no longer fulfills demand, are commonplace - especially in well-established neighborhoods and in almost every municipality in the country. Such was the case for the residents living along Main Street — from Elm Street to Madison Street - in Pella.
Having been installed several decades earlier, an existing water main now lacked the capacity needed to meet the increasing demands of a growing neighborhood. After experiencing fluctuations in water pressure and supply during peak usage times, affected residents petitioned the city for a solution.
“Repeated fluctuations in pressure and supply, especially during the summer months, prompted concerns that the existing water line was no longer capable of keeping up,” True said. “There really weren’t any structural issues, leaks or anything like that. It was more just that fact that an old line could no longer handle the increased demand. What the city wanted to do was upgrade the capacity serving their neighborhood to match that of newer water lines installed in areas of recent development.”
Horizontal Boring & Tunneling landed the job after submitting a bid in response to the job description posted on the Internet. Having previously completed several trenchless projects in central Iowa, both True and the company’s crew was familiar with the rich, heavy clay soils that awaited them.
The project consisted of installing a 12-in. (30.5 cm) water line in a well-established neighborhood with huge trees, meticulously landscaped yards and stately, century-old homes. The original plan design called for the project to be completed using the open cut method. However, that quickly changed once True and the project contractor met with city officials to discuss a different approach as the advantages of HDD were obvious. A trenchless install would minimize disruption to the neighborhood and ultimately reduce costs by eliminating the need to break up a long stretch of sidewalk and several driveways, not to mention preventing damage to lawns and landscaping that would be unavoidable using open cut.
“Given the town where the project was located, it didn’t take much to convince officials the job should be completed using HDD,” True said. “Basically, we saved 1,500 ft (457.2 m) of sidewalk that ran in front of nicely maintained yards and avoided limiting driveway access for residents along the installation route. There would be no disruption to their daily routines, very few inconveniences and minimal invasion to the landscape. With the exception of our entry and exit pits, there was relatively no above-ground digging involved.”
Returning Home for Duty
Aside from some good-hearted ribbing focused primarily on how it was that a Nebraska-based company had landed the Pella, Iowa job, the good-natured residents of the proud Dutch community, whose stately homes line the installation route, were delighted that one of their own — a Vermeer D36x50 Series II Navigator horizontal directional drill with a 15 ft (4.8 m) Firestick drill rod — had returned home in the line of duty.
“We own several Vermeer drills but chose the D36x50 Series II to complete this project for several reasons,” True said. “By and large, because of the rod capacity that is capable of holding over 600 ft (182.9 m) of drill stem and the fact that we would be working in a residential area, so we didn’t want the weight and the footprint of setting a larger machine in there. It fit in the spot and had the pump and rotary capacity necessary. Plus, we didn’t have to hand-load many additional rods to complete the longest of the three bores.”
Three Bores, Two Weeks, One Drill.
As specified by the drill plan, the Horizontal Boring & Tunneling crew had 14 days to complete the job once they arrived on site at the beginning of November. With many of the world’s leading HDD experts located just a stone’s throw away at Vermeer world headquarters, city officials were well-prepared, having already located and potholed the location of existing utilities. This included sewer services, which marked each utility and completed the measurements off of the sewer service cards along the entire route by the time True’s crew arrived.
Despite making some adjustments to the drill plan to accommodate the location of an unanticipated sewer main, the crew was able to set up and complete each of the three pilot bores all in one day. Barring some adjustments that were required in order to navigate the maze of underground utilities present along the bore path, True was happy with the production rates his crews were able to maintain throughout the duration of the project.
One glitch was discovered at the time the first entry pit was dug: a secondary sewer system that paralleled the route of the new water main at a depth of approximately 22 ft (6.7 m), with several houses tied to it. Despite this being a secondary sewer, the line was connected to a common service that extended to a manhole and then on to the main sewer located directly in line with where the new water main was to be installed. Luckily, it was discovered at the beginning of the project so the city was able to reposition the manhole 3 ft (.9 m) with no disruption to service or a major change in the drill plan of the new water main.
The length of each of the three bores: 230 ft (70.1 m), 640 ft (195.1 m) and 730 ft (222.5 m) respectively, was dictated by valve placement. This was another advantage for using HDD as each of these locations would have to be excavated anyway to accommodate the installation of new valves for the upgraded water main. As a result, the only concrete damaged in completing the entire project was that which had already been slated for demolition at the precise locations where the new valves were to be installed. Depths weren’t much of a concern, ranging from 6 to 10 ft (1.8 to 3 m), and ground conditions - consisting of various densities of clay - were fairly consistent throughout.
The first 230 ft (70.1 m) bore was completed in one day followed by pre-reams of 16 and 22-in. (40.6 and 55.9 cm) that were both completed in one day as well. Having navigated around the entire existing infrastructure on the first bore, the subsequent bores were completed with relative ease, taking the crew only one day each to finish.
The 16-in (40.6 cm) pre-ream of the longest bore took two days to complete, plus one day for the third and final shorter bore. True used Vermeer helical-style tooling to complete the reams and pulled the product back through with a 20-in (50.8-cm) fluted-style packer. The entire 1,600 ft (487.7 m) of 12-in (30.5-cm) c900 Certa-Lok material was pulled through in less than three hours.
“We had a lot of people stopping by to check out the progress,” True recalled. “I remember one day a couple stopped by and said ‘I see you guys are running a new D36x50 Series II. Nice choice!’ While I expected a fair amount of interest in the job, I must admit I didn’t expect that. Fortunately, we were able to complete everything without a hitch, to the satisfaction of all.”