Retention/Detention Systems

Underground Stormwater Storage Products have become a popular BMP as Developers and Commercial Property Owners strive to save land space that can ultimately be used as an available building area to generate more income for a project. The placement of these Stormwater BMPs underneath Parking Lots, Roadways, Athletic Fields and set back open space areas permit volumes of Stormwater runoff to be stored underground, where it can be reused, discharged to public storm sewers or infiltrated into the soil to recharge local aquifers.

To protect underground CPP Pipe Stormwater Detention/Retention systems from trash and sediment accumulation as well as floatable items, such as plastic bags, from entering an underground pipe Storage System, CPP, Inc. recommends the use of the Catch Basin inserts screen called Trash Guard ®. These durable plastic screens have been demonstrated to remove not only unsightly trash, but also parking lot sediments laced with regulated metals, Nitrogen and Phosphorus. By removing the unwanted trash and toxic sediments from the Stormwater flow at the Trash Guard ® protected Catch Basin, CPP underground detention systems last longer because they are not becoming clogged. At numerous locations from mountains to the Carolina and California coasts, the cleaning cycles required of Trash Guard ® protected Catch Basins has been either Quarterly or Semi-Annual under a variety of rainfall and topography conditions. Removal of trash and sediments from a Catch Basin is much less expensive than from an underground BMP storage system once the Post Construction life of a project begins.

Rainfall runoff control with CPP Parking Lot Retention-Detention filtration systems for stormwater infrastructure site utility development.

Trash Guard ® is a patented product: patent # 7276156
Inserts Screens Available in three sizes: 23″, 28″ & 34″
For more information on the Trash Guard please visit their website:

CPP Stormwater Best Management Practice (BMP) Retention-Detention systems mimic nature’s rainwater filtration polishing process for sustainable development civil engineering.

CPP special fabricated Manifold T’s and plastic culverts perform at near zero deflection under traffic bearing pavement, thus creates great labor savings with faster construction site work schedules.

Onsite stormwater control Retention/Detention Infiltration beds save valuable development space.

CPP offers a variety of Catch Basin Inlets required for parking lot Detention-Retention Systems.

48″ Tee with 12″ Clean out.
36″ Triple Tee Manifold.