2020 Project of the Year Rehabilitation Honorable Mention: Rehabilitating 1,890 ft of Water Line
Much of Kansas City, Kansas has its potable water infrastructure maintained by Water One, a quasi-municipal water utility that prides itself on the quality of its water and its ability to repair and install pipes with its own construction teams.
Maintenance on these lines can be challenging not only due to aging pipelines and corrosion, but also due to costs associated with permitting around railroad lines, public roads and thoroughfares, and other infrastructure. Due to operational time constraints, the project was required to be completed in the middle of winter, with temperatures on the job site consistently averaging below freezing.
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In this case, a 24-in. potable water line was in need of rehabilitation but it ran 1,890 ft under a freshly paved road, railroad crossing and highway overpass. Not only that, but the line had a 90-degree bend, a 30-degree bend, and a 45-degree bend along its run, limiting rehabilitation options.
The Kevlar-reinforced flexible polyethylene pipe manufactured by Primus Line was the optimal solution for this project.
During the evaluation process for this project the host pipe diameter of 24 in. was compared to the Primus Line 20-in. diameter pipe, the DN500, and was determined to be more than enough capacity. Although slightly undersized, it was determined that Primus Line would maintain an adequate flow rate, with a C-Factor of 150, compared to the existing host pipe.
The flexibility of the liner allowed for the navigation of one 90-degree bend and two 45-degree bends in this line, while the Kevlar weave of the liner was able to handle the required pressure the line would be under during operation: about 100 PSI.
Since no excavation was required for the bends under the roadway, the entrance and exit pits were located outside of high traffic areas, minimizing any impact to local traffic. Upon seeing the line was in good condition, the Primus Line was brought on site and inserted from the reel at an angle of 180-degrees, being pulled out of the exit pit at a 45-degree bend by a winch.
After this, the patented connectors were installed to anchor the Kevlar line in the host pipe and reinstate the water line via an ANSI flange and spool piece. The Primus process was successfully completed by the expert workers of Water One and was finished in less than four days’ time.
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Why Project is Outstanding:
t least three bends in this line, including one at a 90-degree angle, were located directly beneath a freshly paved street and recently redone railroad crossing. The alternative option for repair was to dig and replace, increasing the cost of the project by $1 million. It would not only increase the price of the repairs due to the extra digging and permitting required to remove the bends, but it would also increase congestion and traffic in the area, adding an additional cost to local businesses and commuters.
The additional pits required for the removal and replacement of this pipe was not the only concern. The required pressure rating of 100 PSI for this now-20-in. potable water line navigating these sharp bends would be a steep (if not impossible) ask for any other trenchless technology. Primus Line’s flexible, Kevlar-reinforced technology provided the maximum operating pressure required for the pipe.
With cost savings of $1 million, a short installation period of only four days, no additional permitting from local municipalities required, and a preservation of normal traffic conditions in a busy area with nearby business park, the choice was clear.
No other trenchless technology would have the ability to navigate these bends, maintain the required pressure, and be able to be installed in such a short time period.
Project Owner: Water One
Contractor: Water One
Vendor: Primus Line
Value of Trenchless Project (US$): $253,075
Sharon M. Bueno is managing editor at Trenchless Technology.
