StormTree™ is not a closed concrete box, therefore the amount of runoff treated is not based on the size of a concrete structure. StormTree relies on direct infiltration, as well as an expanded engineered media layer to treat larger drainage areas. Our standard 7’X 5′ system can treat up to 0.50 acres (or greater) with a smaller footprint than closed box systems. Our systems can be integrated with conventional stormwater structures, stormwater chambers, drainage piping, or simply as a “stand-alone” system.

Precast Concrete Frame

Can be configured in multiple ways to suit the most demanding site constraints. It is designed to support HS-20 loading and does not need a crane to be installed. The surface is coated with a salt inhibiting epoxy coating, and can be colored to suit an aesthetic requirement. Optional fiberglass frame also available where HS-20 loading requirements are not necessary.

Media Matters

The engineered media within the system serves two important, yet somewhat contradictory functions: (1) provide rapid infiltration; (2) maintain ample soil water to allow for microbial activity and sustain healthy tree growth. We have developed 3 non proprietary media “recipes” each of which provides just the right balance of infiltration and moisture holding capacity and is designed to blend with existing (native) soils assuring unrestricted infiltration and tree root migration. The media is pH neutral and chemically inert therefore guaranteeing that no nutrients are introduced into the subsurface soil matrix.

Tree filters, like other bioretention systems including rain gardens, have a high degree of stormwater pollutant removal capacity. The physical, biological, and chemical remediation functions are hard at work to separate, partition, adsorb, metabolize, and sequester both organic and inorganic constituents in the stormwater train.

                         Reported Pollutant Removal Rates for Tree Filter Systems*
                           Pollutant                          Removal Rate
      Total Suspended Solids (TSS)                               >85%                
               Total Phosphorus                               >63%
                   Total Nitrogen                               >50%
                      Total Metals                          50% to 88%
                   Oil and Grease                               >85%

* Based on published 3rd party testing of generic and proprietary tree filter systems

We Use Trees In Our Systems

Since the unique open design allows for unrestricted tree root expansion, we have a large ornamental tree list to work with. We primarily incorporate small to medium sized trees which typically achieve a mature height of no greater than 30 feet. This works particularly well in situations where overhead electrical wires are an issue.

We provide our client with our preferred tree list and/or consult with the landscape professional regarding their alternative selections.  We provide the tree as part of our turnkey systems, or coordinate selection and installation with the client’s contractor.  Balled and burlap or bare root trees in the 1.5″ to 2″ caliper range are typically specified for the newly installed StormTree system. However, trees up to 2.5″ caliper can be utilized in specific applications. Trees are inspected for potential girdling or other deformities that could hinder establishment and growth prior to final selection.

Small Street Trees