One of the most frequent questions we receive when talking to engineers is, “Do the products get water quality credit?”
Up until recently, the answer was no. This is because the StormTank management systems themselves are nothing more than the storage mechanism incorporated into the overall project design – just like the stone storage of most manuals, but at a much higher void space.
The good news is that the answer has changed over the past year with the completion of a testing configuration of the StormTank Module Debris Row. The test simulated an installed Debris Row in a testing rig and found that removal efficiencies exceeded 96% based upon a footprint of product calculated by the inflow rate times a coefficient. The second was computational fluid dynamics (CFD) analysis of the StormTank Shield, which showed that 100% of floatables and oils are retained, while removal efficiency depends on inflow rate and size of the structure.
What seems to be more interesting to most engineers is that the system can actually receive credits depending on the application for which it is being installed. So what does that mean? If you are installing the system as an infiltration basin, you can get the credit per your local or state manuals, and in addition, if you are installing it as part of a bio-retention (rain garden) or pervious pavement area, you can also receive the credits for those applications. These application-based credits apply to all StormTank systems.
For more information about water quality credits and the StormTank testing mentioned above, contact your local representative, and we’ll be happy to share the technical details with you.