Subsurface systems are mainly designed for stormwater detention, where surface runoff is stored for a shorter term then released into the sewer system afterwards. Where feasible site conditions occur including design, siting and construction, subsurface systems can also render retention—in such a way that all open-bottom systems allow for soil infiltration with the exception of closed-bottom vaults and tanks.
Together with our highly skilled team of engineers, we will tackle all four subsurface systems below for your pros-and-cons comparison:
Typically constructed from precast concrete, cast-in-place concrete or corrugated metal pipe (CMP), storage vaults and tanks are closed concrete systems useful for sites with undesirable infiltration, constrained space or internal systems. However, cross out all these site criteria above and you can overhaul your storage vaults and tanks from closed to open-bottom systems, allowing soil infiltration which effectively reduces the water detention level.
As its name implies, gravel bed systems consist of stone aggregate storage bed. These excavated systems filled with gravel usually take up a large contact area with the soil, rendering high infiltration rate when stormwater seeps through the spaces of your coarse aggregates.
Perforated pipes combine the two types of subsurface systems above—such that 4 to 48" parallel pipes which are embedded in gravel bed for stormwater holding capacity also act as your storage tanks, yielding you two-in-one benefits for your soil infiltration.
Similar to the third subsurface system mentioned, stormwater chambers are very much akin to gravel-embedded perforated pipes except for its intrinsic use of plastic storage chambers. Intended to be installed based from the manufacturer's specification, this prefabricated subsurface system gives you a dual advantage in stormwater storage through maximum void ratio in storage chambers and maximum void space in the gravel bed.
Which subsurface system you choose, New York Engineers ensure you that your stormwater design will cater to the most exacting specifications for optimal performance.