- ENGINEERING INFO
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The City of Minot, North Dakota has experienced significant growth in recent years due to the oil boom in the western part of the state. Located on the edge of the Bakken formation, the city and its surrounding area has a population exceeding 70,000 people. Minot is the largest city in the area and plays an important role in supporting the energy industry. The City also serves as home to many people who work in the industry.
With a population growth rate of approximately 20% per year over the past five years, much of the city’s infrastructure was rapidly becoming undersized, including the wastewater collection system. The sanitary sewer trunk line had reached 90% capacity and a new trunk collector system was urgently needed. Apex Engineering Group of Fargo, North Dakota was tasked by the City with designing a new 24-inch wastewater force main and a 30-inch gravity sewer system. Final alignment for the 24-inch section was along the busy and crowded 55th Street corridor which crosses US Highway 2, a critical east-west bypass artery for truck traffic in and out of the Bakken formation. The alignment also intersected the Burlington Northern Railroad main line, as well as numerous fiber optic lines for television, telephone, BNSF rail operations, and Minot Air Force Base communications.
Given the importance of minimizing impact to Highway 2, Apex Engineering determined that directionally drilling under the highway was the best solution. Shortly after crossing under the highway, the pipeline needed to also cross under the BNSF railway. With the prospect of a 3,200-plus foot directional drill and the need to cross a major railroad right-of-way with a 320-foot jack & bore installation, Apex turned to Fusible PVC® pipe for the trenchless sections. Fusible PVC® pipe’s proven track record on hundreds of complex directional drill projects, coupled with the ability to downsize the steel casings required by the railroad company, made it a natural solution for the project. Bell-and-spigot PVC pipe with mechanical restraining harnesses would have required a 42-inch steel casing versus the 30-inch steel casing used for the 24-inch Fusible PVC® pipe.
|Pipeline Details and Project Summary|
|Project:||55th Street Force Main and Gravity Sewer Improvements|
|Length/Size:||24” DR21 Fusible PVC® Pipe|
|Pipe Size:||Directional Drill: 3,210 LF Jack & Bore: 320 LF & 80 LF Slipline: 760 LF (steel casing installed open-cut) Open Cut: 1,090 LF|
|Owner:||City of Minot|
|Engineer:||Apex Engineering Group|
|Contractors:||S.J. Louis Construction (General Contractor) Nomad Pipeline Services (HDD Subcontractor)|
In addition to the 320 foot jack & bore installation, and to accommodate future expansion in its right-of-way, BNSF required another 760 feet of 30-inch steel casing to be installed open-cut, with Fusible PVC® pipe inserted as the carrier pipe. Finally, the section of the pipeline alignment between the directional drill and the two steel cased sections was designed to be fully restrained. In order to maintain consistency and continuity, Fusible PVC® pipe was installed via open-cut in this area as well.
S.J. Louis of Rockville, Minnesota was low bidder and was awarded the project in April 2014. S.J. Louis installed all of the direct bury, jack & bore, and steel cased sections, while Nomad Pipeline Services was selected to perform the directional drill work. Nomad completed the drill with an American Auger 440 Drill Rig. Pull-in was completed on September 5, 2014 in a little over 12 hours with maximum pull force topping out at 150,000 pounds. The entire pipeline was pressure tested and passed after all open cut and trenchless sections were completed.
Dan Jonasson, Director of Public Works for the City of Minot, provided the following insight: “The City of Minot had utilized fused PVC pipe on other bores, but nothing approaching this length. S.J. Louis, Nomad, and Underground Solutions provided us with a solution that addressed all of our issues and concerns, and in a very cost effective way. Decreased boring size, downsized casings, and a shorter installation timeframe were a win-win for the City. We prefer fused PVC pipe because we can use standard fittings for connections and repairs if needed, which lowers the amount of non-standard fittings we need to keep in inventory.”
Tim Paustian, Project Manager for Apex, added: “Fused PVC pipe proved to be an excellent product for the project and the various required applications. By utilizing multiple trenchless techniques, including a very challenging directional drill, the City of Minot realized countless benefits through limited traffic disruption in the HDD areas and decreased casing size in the boring and jacking areas. UGSI was an excellent partner in providing technical support on both the engineering and construction ends of the project.”
Mike Spruill, Superintendent with S.J. Louis on the 55th St. Minot project, said, “Underground Solutions did a great job for us in Minot. We look forward to working as a team on another project in the near future.”