Where runoff needs to be filtered and then transferred into the stormwater system, a bioretention- or flowthrough-planter is used. This typically occurs next to or on top of buildings, or draining roof areas. Pollutants are removed as runoff passes through biotreatment soil mix, and is collected in an underlying drain rock layer containing a perforated drain. The filtered runoff is directed to a storm drain or other discharge point.
Tournesol turnkey bioretention systems are easy to specify and delivered complete. Just add locally-available bioretention media and plants. Available in three standard and many custom sizes, the lightweight GFRC concrete can be used in most on-structure applications. Multiple units may be connected or ganged for high drainage inflow requirements using Tournesol's "Scoop" system. Tournesol Siteworks' engineering staff is available to consult on filtration requirements. Ask your local salesperson for details!