950 N Sewer Trunkline
This sanitary sewer project represents an exciting first for Northwest Pipe Company—the first installation of Perfect Pipe (HDPE-Lined RCP) manufactured at our Geneva Pipe and Precast plant in Orem, Utah. The Central Davis Sewer District is expanding their service area in Kaysville, Utah, with a new 3,400 LF trunkline consisting of 24- and 32-inch Perfect Pipe. The trunkline provides an outfall for expected future development adjacent to the planned West Davis Corridor.
Perfect Pipe was selected for this project over non-lined alternatives for numerous reasons, including corrosion resistance. The integrated HDPE-liner protects concrete from microbial induced corrosion and extends the longevity of the sanitary sewer system. Other factors project designers considered in specifying Perfect Pipe include:
- Durability and Constructability– Installation depths for this project reached nearly 23 feet, which raised concerns about loading of soil on the pipe. There were also constructability concerns about installing and welding HDPE pipe in such a deep trench. Perfect Pipe offered the durability to withstand soil loading forces, while offering an integrated joint coupler eliminating the need for field welds and still creating watertight joints.
- High Groundwater Concerns –Perfect Pipe products prevent infiltration, which can reduce the capacity of the pipeline.
- Production Schedule – Our team worked with project stakeholders to ensure the product was manufactured and delivered on time, ensuring the construction timeline was met.
Utilizing a crew of seven workers with three in the trench, contractors from Red Pine Construction successfully installed the Perfect Pipe trunkline at a rate of up to 150 LF per day—an impressive speed for the install depth, which reached 22.9 feet. The tallest manhole for this project had a rim-invert difference of 21.06 feet.
In addition to the HDPE-lined RCP, Geneva Pipe supplied a 60-inch lined precast manhole for this project, which provides a corrosion-resistant junction within the new sanitary sewer system consisting of an FRP-lined manhole base and HDPE-lined manhole risers.