Stormwater management requirements have become common practice for most site development. With the implementation of the EPA’s Phase II Stormwater Program (NPDES), these requirements will expand even further.
CSP systems provide cost-effective solutions to stormwater management requirements. Subsurface practices such as detention, infiltration and filtration provide a method to meet stormwater objectives and permit efficient use of the site. Underground systems eliminate the hazards, risks and poor aesthetics of above-ground ponds.
Detention Systems
CSP detention systems have been used predominantly to temporarily store runoff and release it at a predetermined rate. Large pipes are installed underground, often beneath parking lots, allowing above-ground use of the site. The use of this land for other purposes results in substantial cost savings.
Infiltration
Where the proper soils are present, perforated CSP can be used as an infiltration system. This water quality practice duplicates undeveloped conditions by directing runoff back into the ground. CSP has the advantages of minimizing excavation, as compared to a conventional infiltration trench, and allowing access into the system.
CSP Sand Filters
One of the most promising techniques of providing water quality improvement is through filtration. Runoff is passed through a filter media, typically sand, for treatment purposes. These systems provide high pollutant-removal efficiencies and are particularly appropriate for the “ultra urban” environment.
Versatility in Fabrication
CSP can be readily fabricated into elbows, tees, manifolds, inlets and outlet control structures. This flexibility in design and system layout cannot be achieved with other materials. Also, plant fabrication means faster installation and lower job site costs.
Strength
CSP provides a high-strength containment system that can be used for heavy loading and low cover conditions. The combination of steel’s proven long-term material properties and fittings reinforcement design criteria (ASTM 998) ensures product performance throughout the life of the structure.
Service Life
Inspections performed by Parsons Brinkerhoff and research by Corrpro Companies confirm that CSP stormwater management systems are performing well. While conditions in most systems are benign, a broad range of CSP coating systems are available to economically meet any project design life up to 100+ years.