2728 Capital Blvd Sand Filter – Retention System

Published by Hank Gottschalk

In January 2022, CP&P was asked to look at a combination storm water retention and sand filter system for a project called “2728 Capital Blvd” located just outside of downtown Raleigh, NC. The project consisted of a renovation to an existing warehouse with additional parking and storm drainage required. The project documents did not specifically detail the storm water retention and sand filter system that would need to be located next to the parking lot while still allowing for an aesthetic landscaped entrance.

Fortiline Waterworks of Raleigh contacted the sales and estimating staff at CP&P’s Dunn North Carolina Precast Plant for help with providing a design and a quote for the project. With assistance from our engineering team, plant input, and several years of experience, the team was able to recommend a design utilizing a “Double Cell Monolithic Box Culvert.” The design consisted of two runs of 7’-6” x 5’-6” (inside) Double Cell Monolithic culvert with an overall system footprint of 34’-0” x 32’-8” (1111 square feet area) providing approximately 4,950 cubic feet of storage/treatment capacity. The heaviest precast concrete section weighed approximately 40,500 lbs.

After the design was approved, the team at Dunn successfully completed fabrication of the sand filter system as requested, on time. However, while the installation crew was excavating the area for the system they ran into a Fiber Optic line that no one knew existed, or who owned it, or if it was even still in use. After about two months of setback, the owner was able to slightly adjust location of the new sand filter system in order to clear the conflict and avoid any problems with potentially hitting the Fiber Optic line.

The system was all delivered and installed in about one day, even after having a few “set-backs” on the site.

Great job Team Dunn on another successful project!