When a storm water management project plan left the material choice to the discretion of the contractor, Northwest Asphalt had an important decision to make. Initially, the contractor planned to use polypropylene pipe, under the assumption it would provide cost savings. However, once they realized mandrel testing could set the project timeline back and increase costs if even one plastic pipe needed to be replaced, the contractor changed their preference to Reinforced Concrete Pipe manufactured by County Materials. Concrete pipe is factory tested to ensure its strength and rigidity can withstand elements over a prolonged service life without the need for additional maintenance, making it the preferred choice of engineers and contractors.